One Week Wonder

Lucid Lynx on an iBook G3

2012-01-09T21:24:00.003Z

Way back in September '09 I blogged about my xubuntu 9.04 install (twice) and finally, in January 2012 I decided to upgrade to xubuntu.. a whole year later! As usual there were problems with the display, but now it's sorted I have an even better machine than before, so I thought I'd use it to write this blog.

Every new version of xubuntu seems to improve upon the old one, despite the sluggishness of new software the O/S seems somehow to keep up and delivers me a nicer experience as well as a few hurdles to get over.

So how is this one different? My first step this time was to backup all my old home folder to some CDs - because I wanted to triple-boot the iBook into Mac OS X, Mac OS 9 or Linux. I wanted Mac OS 9, because I have an old Dazzle USB composite video grabber which doesn't work with Mac OS X AFAIK, but I wanted to grab better quality videos and images of my FIGnition DIY 8-bit computer in action!

But of course, Linux is essential for running anything new, e.g. this version of Firefox I'm writing the blog on.

The first hurdle was the installation. I found a guide on LowEndMac which recommended running the alternative CD installer. Either way, I found the disk image too big for writing to a CD, even using the command-line hdiutil so in the end I wrote it to DVD using my iMac G5; and then booted it on my combo-drive iBook. It wasn't a problem installing via the text screens, in fact it's better because the response time is so much quicker; I recommend it from here on!

As usual, the second hurdle was the video display mode. For some reason no xubuntu setup I've ever tried has initially worked in the correct video mode and this is no exception. What was worse this time was that after 9.10 ubuntu stopped using the xorg.conf and instead auto-detects the modes, so I couldn't simply edit it. Fortunately, a number of links tell you what to do:

Basically it involved booting into text mode from Yaboot:

Linux init=/usr/bin/bash rw

creating the xorg.conf:

sudo Xorg -configure

and copying xorg.conf.new to /etc/X11/xorg.conf. I didn't need to add all the special device and monitor sections as before, because the auto-generated one actually had the correct primary setting listed as I wanted (except it's chosen 24-bit colour instead of 16-bit colour).

So now I have a new lease of life for my iBook - Yet AGAIN! FireFox looks modern, I've restored all my data; the eject button works for CDs (in 9.04 I needed a command line utility) and of course it includes lots of the newer features. One of the best things is that the trackpad is no longer over-sensitive, the cursor doesn't skit around the screen and set the typing position to a random location merely because my fingers are close to it! Lovely, lovely, these people are doing a great job!

I'm happy! Hope this is of some help :-)

FIGnition HiRes Graphics, API: RFC.

2011-11-24T12:46:00.003Z

This is a short post describing a proposed Bitmapped Graphics API for FIGnition.

Bitmap Format

A FIGnition bitmap (including the display) is stored as a grid of 8x8 bit tiles:

etc...

A bitmap itself is specified explicitly using a pointer to the bitmap and its dimensions in tiles: y*256+x.

In the case of the display the bitmap is 20x20 tiles, representing 160x160 pixels. A tile format is good for being able to efficiently copy bitmaps to the FIGnition's serial memory, because a single 8x8 tile only requires 11 SPI accesses compared with 32 SPI accesses if the target bitmap was a simple raster. Better savings are made if the target bitmap is larger, an 8x16 bitmap requires only 19 SPI accesses compared with 40 SPI accesses for a simple raster.

Video Prefetch

In the FIGnition's bitmap mode, program access to SRAM must be interleaved with video fetching from SRAM. Since the SRAM chip never provides a means of correctly interrupting an SPI access (you can't read it to find out what operation was last being used and what the last address was); we rely on the SRAM access being interrupted during Forth ROM access; program jumps or memory accesses frequently enough to be able to prefetch the data during the video scanning. This means you can't unroll loops too much in hires mode or video glitches will occur.

Video Prefetch fetches a whole 160 byte row of the frame buffer at a time and copies it to internal RAM, the RAM used by the normal video RAM in text mode. This operation requires 160µs every 512µs and thus is within the bandwidth of the memory system; leaving around 352µs of which 88µs is free for program execution (around 16µs for each of the 5.5 scans), enough for typically 11 instructions (at around 120KIPS on average, the raw average performance of FIGnition). It's likely therefore that program execution will be suspended during video scanning (currently it isn't) and this will reduce performance by about 0.5%.

The prefetching needs to prefetch a whole 160bytes, because the video scan must output it in raster order, displaying every 8th byte of the buffer per scan byte and repeating the same process starting one byte further for the next scan.

Therefore, we have to use a 2x 160b buffers for video scanning, leaving 728-320 = 408b free for a blitter cache called the Tile Buffer.

The Tile Buffer

In general, using serial SRAM to blit data represents a major bottleneck in the system. Therefore it's advantageous to use internal RAM as much as possible, in our case as a cache of tiles for our bitmap images (such as sprites) as well as using it as a cache for parts of the frame buffer when we write bitmaps to the frame buffer.

408 bytes provides room for 51 tiles. One tile (tile 0) will be used as a single tile cache for plot. The subsequent tiles are intended to be used by your program (1..50) and the tiles working from the end of the buffer, backwards (50..11) are to be used for caching the frame buffer. At maximum, only 40 can ever be used. For example, if you use a number of 16x16 sprites and no other larger graphic objects, in practice only 2 rows of 3 frame buffer tiles will be used, 6 tiles.

Even though there's only 51 tiles available, this doesn't mean FIGnition graphics are limited to 51 tiles; it just means you can only cache 51 tiles at any one point: changing the cached tiles won't change anything on the screen, because the frame buffer is stored independently. So you can cache a number of tiles; do some blitting; cache some other tiles; do some more blitting and it'll all work out correctly.

Blitter API

Here's the proposed Blitter API (the parameters may change a bit, it's the concepts that are important here).

The first aspect is support for tiles. There's a single function, to copy from SRAM to tiles:

bitmap dim dx dy tile# tile

This copies the bitmap whose dim is height*256+width with a shift of (dx,dy) pixels to tile tile#. Note, this means you can pre-shift tiles by up to 8 pixels in 2 directions. If the tile is shifted in x by more than 0 it'll take up width+1 tiles, and similarly if it's shifted in y by more than 0 it'll take up height+1 rows.

The blitter itself works a bit like emit; having a pen location where tiles are to be blitted next.

x y at ( in graphics mode sets the x y pen coordinate for the blitter)

dx dy clip ( clips from the pen coordinate to dx dy in the current frame buffer, blits outside the clip area aren't displayed).

tile# dim blt ( blits a single tile to the frame buffer in xor mode).

tile# dim tile2# dim2 x2 y2 2blt ( is a double-blit routine; blitting both tile# and tile2# to the frame buffer in order to eliminate flicker it uses an xor mode).

tile# dim xrep yrep blts ( is a background tile blit routine; copying a single tile to the frame buffer at the current position, it doesn't use xor).

This graphics system has a number of useful characteristics.

It splits the blitting into SRAM->Internal RAM and Internal RAM -> SRAM operations; thus reducing the contention for SRAM at any one point.
It increases the re-use of Internal RAM by being able to cache tiles. Thus, repetitive tiles can be easily reproduced using blts and repeated use of sprites is possible (e.g. with galaxians or space invaders where the same graphics are used multiple times).
It allows blitting to be treated like printing; the blit position is advanced tile by tile.
It allows characters to be displayed easily, we use use the address of a character from the character set in firmware as the tile to be displayed (simple tiling is just a cmove).
It's pretty minimal. You can get away with knowing only 3 routines and then later expand your knowledge to all 5!

I'm considering adding a built-in scroll routine too. Here, we'd fill tiles with the background data to be revealed by the scroll and then use dx dy scroll; where dx dy are values in the range -8 to 8. The problem here is that theoretically we'd need up to 80 tiles to do this, but we only have 51.

Performance Estimations

Some rough estimations follow, though they could be up to 2x slower or so than these estimates; be warned!

blts could operate at up to roughly 2us/byte or 500Kbytes/s, so we’d get a full-screen blts in 6.4ms. Tile/blt would be slower. 2x2 graphics would operate at roughly 2us / byte for the tile+40us? blt would operate at around 4us/byte, because each byte must be read and written once, so that’s 32*2+40 + 72*4+10 = 402us for a 16x16 sprite. 2blt would be a bit slower, but it probably won’t be worth it if it’s more than 50% slower than using blt (otherwise we might as well just use blt twice). So that’s 603us for a 16x16 sprite. Let’s say we need 12.5Hz for OK performance and we can’t use more than 70% CPU, so that’s: 603/.7 = 861µs for a 16x16 sprite, *12 = 10.8ms = about 92 16x16 sprites maximum/second.

Of course, the performance for blt can be better if some sprites are always being cached then we save 100µs / sprite, or 111/second.

I think these guesses are decent for the kind of architecture we have here, but the real question is: is this kind of performance good enough for 8-bit games? If not, we'll have to approach it differently.

Comments are very welcome!

FIGnition HiRes Graphics: The Rejects

2011-11-01T15:08:00.007Z

This is an introduction to the High Resolution Graphics Support on FIGnition, somewhat documented as I develop it. Because I'm working on this at the same time, there's probably going to be a lack of actual graphical images explaining what I'm doing - for the moment I just want to give the gist of the development up until now.

FIGnition development started just over a year ago and as normal for all my developments I document my work in a journal as I go along. I first started my FIGnition journal with an article about Tiled graphics.

Tiled Graphics

Tiled graphics have an illustrious history, mostly because they were used extensively for Games Consoles when RAM was limited. The 6502-based Nintendo Entertainment System, NES used a sophisticated Tile-based system. Arcade consoles such as PacMan also used tiled graphics as is revealed nicely when you exceed the 256th level. Many AVR based games consoles use a form of Tile-graphics, because Tile graphics are a form of character-based graphics and so you can save RAM by only requiring a character RAM table, where each byte points to a graphical tile in Flash.

At the time I was going to use an AtMega328, which provides 2Kb of RAM, so I was willing to allocate 1.5Kb to video. In Tile mode, the Video display of 240x192 is divided into 16x8 pixel regions called tileRefs. There’s 15x24 of these:

This way I only need half the number of bytes for the text display. The rest of memory is divided into tiles each of which occupies 16b. There are 73.5 tiles. The last 0.5 of a tile contains meta-data for the game mode: The offset for TextField 1 (2 bytes); the offset for TextField 2 (2 bytes) + 4b spare.

Each tileRef is a single byte. Byte values in the range 0..127 are text tileRefs, they point to a pair of characters at offsetForTextField(tileRef.y/8)+tileRef*2. These characters are displayed like normal ROM characters, and can be true video or inverse. Thus we can cover the entire screen with characters, but we only need as much character data as necessary. Typically a game will need a status line at the top, requiring 2 tiles.

Byte values in the range 128..255 are graphics tileRefs, they simply point to a 16x8 bitmapped tile at offset: tileRef*16.

When I moved to using an AtMega168 I reimagined it at a new resolution: 192x192 = 12x24 tiles, using 288b leaving space for about 55 tiles.

The difficulty with Tile mode is that it's simply very awkward. FIGnition is supposed to programmed by relative novices, so the graphics interface has to be pretty simple. Instead the graphics engine required on top of a Tiled mode requires the programmer to think about how many of the 55 tiles might be free and the underlying firmware has to keep track of allocating and deallocating tiles. So, in the end, despite the fact that it looks appealing (and I spent quite a number of hours working on the concepts), it was dumped and I wouldn't even implement a version of it if FIGnition used an AtMega328 (which is not planned).

Medium Resolution Graphics

Another option, of course is to use medium resolution bitmapped graphics. Here we'd simply use the existing video memory to provide a better graphical resolution, because the text mode only uses a maximum of 4-bits per byte for graphics.

We can work out the consequences easily: there's 728 bytes of Video+UDG memory, so we could support a sensible maximum of: 5824pixels, which at a 3/4 aspect ratio gives 88 x 66 pixels. We can see that although this would be better than the current 50 x 48, it would just give us some pretty boring graphics and wouldn't be worthwhile since no-one would want to use it.

High Resolution Graphics

In the end I decided to go straight to High-Resolution 160x160 pixels graphics - that is if you can call 160x160 high resolution, which Commodore did for their Vic-20 ;-)

The apparent problem is that there isn't enough internal RAM for this resolution: you'd need 3200 bytes. Now you could get enough RAM if you used main RAM, but there are two main issues you'd need to deal with:

The main FIGnition RAM is Serial RAM and it's really slow, running at 1µs/byte maximum vs an effective 100ns/byte for internal RAM (because you need to process it using 2 cycle instructions at best).
The serial RAM is used to run normal Forth programs, so you'd be interrupting access from Forth and the SPI-based Serial RAM simply isn't designed to be interrupted, because there's no way of reading the internal address register on the chip, which means that if the main code was changing the current address being read from, which involves sending a command and the Video interrupt routine ran, then there's no way for the video routine to know what the main code was trying to do and no way to restore the RAM properly to its previous state.

And it turns out both of these problems can be solved. Video is clocked out at 1 byte every 32 cycles and SRAM requires only 18 cycles to read a byte, therefore we can (in theory) read from SRAM and keep up with the video output.

Secondly, and this is really handy - Take note geeks! It turns out that we can interrupt Serial RAM access whenever we assert or deassert the SRAM's Chip Select Line. This is done by activating the PCINT1 interrupt on pin change. So, whenever we try to jump to another SRAM address and we should be fetching video, PCINT1 will be activated and we can interrupt the main code's use of SRAM without incurring any performance penalty at other times; and we don't need to remember what the old state of the SRAM was, because when we return from the interrupt, the main code will set the SRAM address correctly.

So, this is how it'll be done! Tune in to part 2 soon!

The Duplo®code Fallacy

2011-10-13T09:14:00.005+01:00

I've just been watching this BBC news article, which features luminaries from the UK industry talking about the woeful programming skills in the new generation of kids.

Let's make a case here: not only does the education system have computing wrong because we focus on ICT, but the programming industry has the wrong emphasis on computer science, because they believe in teaching kids using powerful environments on powerful systems; when what we need is dirt simple systems and environments.

The case is really quite simple. Firstly, let's consider the programmers in the article: Ian Livingstone (2:14), David Braben (4:00), Alex Evans (6:36). They all learned to program on simple computers. Look at the clip from Making the most of the micro (3:25): it shows a BBC micro, a computer ready to program as soon as you switch it on and a listing from a printer containing a hundred lines of code.

Secondly, we learned to program without the aid of a Computer Studies class: instead our parents bought computers for us and there was basically no access in schools. By the time we got to the class we already knew more about programming than what an entire 'O' level would tell us. The classes just helped us do more of what we enjoyed.

Thirdly, let's consider the opportunities kids have to program these days. You'd think, they would be 'better' than in the 80s, because for all the thousands of hours kids and adults spend on a desktop or laptop computer they're only 2 clicks away from getting into code, only 2 clicks away from Javascript. Or, you could drop into a terminal window and hack out a simple java/C/shell script program within seconds

So why don't they? If more powerful computers and sophisticated environments are what you need and this kind of thing is available now why are there far fewer kids learning to program? Think about it: programming is 2 CLICKs away today, but our generation had to wait until we'd gone home and finished our homework before setting up our puny, slow, memory starved computers with grotty low-res screens, crude languages and unreliable tapes before we could even start doing anything.

How can it be that computers are >10,000 times more powerful and yet an order of magnitude less appealing to program?

The clue has to be in the question: it's the power itself that acts as an obstacle. Look at the 3 programming clips: There's the BBC micro clip, there's no obstacle because the display is directly programmed and you have a nice listing so you can see everything - a few hundred lines of code. It looks fearsome, but it's nothing compared with the David Braben example (4:09). Here, the screen shows a relatively sophisticated environment: there's at least 5 different screen panels; multiple tabs to access different options; a massive screen and you can 'edit' roughly 15 lines of Duplo® code. This is on his 'simple' Raspberry PI computer, which contains 300 million lines of code.

It's that kind of gob-smacking contrast that should make us wake up: all that power and sophistication driving 15 lines of Duplo®code. The computing culture today uncritically equates power and complexity with being better, which means we try to solve problems like the lack of programming expertise by throwing powerful tools at it. It's the powerful tools that are the problem when it comes to learning this stuff, not the solution.

This is why:

People are put off programming, because the tools we use are geared for other tasks. For example, I'm writing a blog instead of coding. It's easy to blog and there's lots of webby distractions, so the effort/benefit ratio of coding is much lower.
Kids get put off programming because the environment is complex. I don't want to boot up an IDE and learn its arcane windows, menus, language, libraries, syntax and frameworks when I start learning. Instead I just want to get a kick out of doing something like making the computer display my name 1000 times: : hi 1000 0 do ." Julz is FAB!" loop ;
Kids get put off programming because the many layers of software adds too much guff to the effort. If I view source on a web page to see Javascript I find it's wrapped in Html (because Javascript is built on browser technology) and outputting to a screen or getting data from a keyboard or mouse or whatever is just so much more effort than on the BBC micro where David Braben learned his skills. The guff affects the third coding example on the video at 8:37, they're editing SQLite database stuff - and that's exciting? Well, of course, it's more exciting than learning Excel!
Kids will get put off programming because creating Duplo®code environments on top of sophisticated systems is patronising and deceptive. Any 7 year old will realise that the real computer is nothing like what they're learning and that the linguistic padding (e.g. the use of the 'green' colour in the language) is magical: that is what's really going on hides a wad of complexity you don't have access to.
Finally, kids will get put off programming if there's a hierarchy of access. Even if I ever think Duplo®code is a real language, my programs will never really run on a real PC/Mac/Linux/Nintendo/XBox/iPhone and be distributed on an equal footing with everyone else's code. It's a world away from when we learned to program when our code ran on computers people really owned and we could have it published in magazines or distribute it ourselves on tapes. So, the kids know... in their hearts... Duplo®code is a waste of time.

It's great that there's initiatives to encourage kids to program today. But our plan is like teaching kids to read using War And Peace, but only letting them read the simple words while we do the rest and teaching them to write by letting them arrange paragraphs and chapters. Nobody in their right mind would teach kids to read or write in this way, but this is exactly what being proposed here.

The real lesson to learn is that we need simple, but real systems. Simple systems have no distractions; they're easy to access; they have a clean and simple syntax; they're not patronising and deceptive and it's egalitarian. Simple systems were the way we learned - that's why it worked.

Enfranchize the workforce

2011-09-30T09:53:00.003+01:00

In a world that's in the middle (or possibly still near the beginning) of a recession/depression, the pressure is on employers to cut costs by reducing workers' pay and making redundancies and so the people who carry the consequences are those with the least power. To defend themselves, employees are increasingly looking to taking strike action.

Striking has a long history within the labour movement. Here's a proposal for a simple alternative for a workers' action. Instead of striking for pay increases during a recession, why not campaign for greater stakeholder influence? That is, it's understandable if there's no pay increase in a recession or depression, but it's not the worker's fault (nor I would argue is it necessarily the management fault either). But if the management can't maintain wages, is there any reason why they can't provide shares in the company?

Campaigning for shares (i.e. shares for individual members) would have numerous consequences.

It'd mean that the workforce would potentially receive compensation for their loss of earnings, albeit deferred to when dividends would become available.
It'd mean that the workforce would have more of a vested interest in the company's success.
It'd mean that all levels of the workforce would have a stake in the company power base: the company would be taking a step towards being a cooperative.
It'd be much easier for outsiders to sympathize with the aims of the workers: it's hard to justify penalizing your employees and simultaneously keeping them disenfranchised when the entire company's existence depends on them.

Enfranchise the workforce - what's there not to like :-) ?

Ref: Maverick.

Accessing Ram on an Intel 4004

2011-09-03T11:18:00.002+01:00

Hi folks,

I've recently been trying to work out how RAM is accessed on an Intel 4004, 4-bit Microprocessor. The most valuable information I've found is from:

http://e4004.szyc.org/iset.html

Whose website provides a javascript emulator for the 4004.

The 4004 is a seriously primitive device. One of its odd behaviours is that it doesn't really address RAM as such. What it does is provide a means of sending an address to a RAM chip and it expects each RAM chip to contain its own address register, this is done with an SRC ixr instruction, which outputs the contents of one of its 8 * 4-bit register pairs on its multiplexed address bus, selecting RAM if the upper 2 bits are [This bit I don't know] and ROM if the upper 2 bits are [Similarly Unknown].

Ram is organised as follows:

You can have up to 8 RAM bank chips which are selected using DCL nnn instructions which simply output nnn to CM lines 1..3 on the chip. (There's the default Ram Bank 0 which is selected when nnn=0, which activates CM0, and the rest nnn>0 which literally output to CM1..CM3, so you can attach a 3:8 decoder and decode the other 8 - though that doesn't quite make sense).

Next up: The Src instruction outputs a register pair as described above. The top 2 bits are ignored by the RAM chip itself. The bottom 6 bits select one of 64 addresses (4 registers of 16 4-bit 'characters'). You can then transfer between RAM and the Accumulator using RDM (to read from the RAM address), WRM ( to write Acc to the RAM). There's also ADM and SBM to add (with carry) and subtract (with borrow) the addressed RAM nybble to/from the Acc (and store in the Acc).

In addition, each 4004 RAM chip supports 4 'status characters', per register - bonus nybbles, so each register really contains 20 nybbles. You can access these using RD0 to RD3 and WR0 to WR3, so you can't index them via registers. It's all very strange.

But it gets stranger still. I/O is also accessed via the RAM and ROM chips which each provide 4-bits of I/O (RAM is output only) which you can access via RDR (read ROM port), WRR (write ROM port), and WMP (to write to the RAM output port).

Anyway, this blog explains why you can access 5120 bits of RAM: (8 RAM banks selected via DCL * 4 registers * 20 nybbles/register) * 4-bits / nybble = 5120 bits.

You can't have it both ways

2011-08-02T15:32:00.003+01:00

My cousin (and president of Birmingham Uni's Atheist society) Benjamin reposted a YouTube video which argues that Christians don't have the objective morality they can often claim to have, they have a subjective morality like everyone else.

OK, so here's a bit of a response, as per these debates I'd be very surprised if it got anywhere, but here goes!

The real problem with the argument is that it fails to distinguish between a command and a moral principle, so for example when the antagonist says: "Today's the sabbath, they're supposed to be put to death if they worked (Exodus 31:15)" the Bible verse is talking about a command, not a moral principle.

The underlying command: that of having a day of rest is still valid (Ex 20:10). Similarly, Lev 20:10 the underlying principle of not committing adultery is still valid. Similarly, Deut 21:18-21 and Prov 20:20, honouring your parents is still a moral principle. So it turns out that all the moral points the verses refer to are still valid, and so the argument here against objective morality doesn't stand.

In which case the Christian's argument is valid insofar that the New Testament maintains that the O.T morality is correct, though the way our failure to maintain it isn't: that's what the New Covenant in Jesus is about.

What's not quite right is the Christian's statement: "The old laws were made in the context of a very different culture and time period." What's happening here is that DarkMatter2525 is injecting the antagonist's definition of subjective morality here as an explanation for the difference between the Old and New Covenant.

In reality, the difference with the New Covenant has nothing to do with a change in the culture and time period. It's to do with the fact that (a) the Old Testament demonstrates that Israel couldn't keep the morality embodied by the law by their own efforts (and neither can we), Rom 3:2-21 (b) Jesus did keep it and because we can be 'in him', God's agreement with Israel is shared with us: Rom 8:3-4.

The key thing here in Rom 8, goes to the heart of what morality is about, since the natural question to ask is why the command in Ex 31:15 is not the same as the principle in Ex 20:10 when both appear as commands. That I'll leave for another time.

-cheers from julz

For reference, here's the transcript:

(Calm expression) "Morality is subjective, the perception of Morality depends greatly on the on context of the culture and the time period. As such it can be uniquely defined and subject to change."

(Angry) "NO, morality is objective, morality comes from God and God doesn't change. A sin is a sin no matter when or where. What's wrong today was wrong yesterday and what's wrong here is wrong everywhere."

(Calm)"Did any of your friends or family do any work today?"

"Yeah."

"Today's the sabbath, they're supposed to be put to death if they worked (Exodus 31:15). And according to the Bible you should condone the killing of adulterers and witches, disobedient children.. (more Bible verses: Lev 20:10, Deut 21:18-21, Prov 20:20, Lev 20:9, Ex 21:15)"

(Shock)"Oh my God! What's That?" (points right, antagonist follows)

"What - What?" ( Christian steals the "Subjective" heading from his antagonist and replaces his old "Objective" heading with it)

"Uh, I guess it was nothing. Anyway, that was the Old Testament, there's a new covenant with Jesus Christ. The old laws were made in the context of a very different culture and time period."

"Hey, you just stole my word."

"I don't appreciate these accusations, why the Hell would I..."

"Hey, Look out!"

"Yeah, right, like I'm gonna faaeeuugghh." (gets eaten by Alien).

FIGnition oxo game! (noughts and crosses/ tic-tac-toe)

2011-07-19T15:13:00.013+01:00

After my doom and gloom blog about the arctic, I thought I'd write a bit of a journal on how to write a simple noughts and crosses game. So, this'll be technical, and fairly involved as it'll include code, but at the same time will give a bit of insight into FIGnition, Forth and simple strategy games.

FIGnition is a real 80s-style computer. It's got enough memory (8Kb) to write simple programs and enough built-in storage to develop them in. The keyboard's somewhat awkward, but I'm getting used to it (I designed it).

The Computer History Museum is running an event called Hacker's delight, and as I'm exhibiting, they've asked me to produce a version of noughts and crosses to be demoed there. Demoing the development is as important as playing the game.

I started by looking at a few versions of tic-tac-toe. It's possible to write a recursive min-max algorithm, but I took my original cue from an online version of Not Only 30 Programs for the Sinclair ZX81. There are some insights into playing the game here.

Firstly, how to number the board. The board is numbered not in the order:

1|2|3
-+-+-
4|5|6
-+-+-
7|8|9

But

1|2|3
-+-+-
8|0|4
-+-+-
7|6|5

And it's done this way to make it easier to analyse the board. Opposite corners have a difference of 4 and subsequent diagonals have a difference of 2. In fact it's best to represent the board like this, because it reflects the real structure of a oxo board: if you rotate it by 90º it's still the same.

So let's first convert the ZX81 game. The ZX81 version simplifies the game by making the computer go first, by placing an 'X' in the centre. It then follows the following strategy:

In the first move (A=1), the computer plays the opponents move+1 (so, if the user played to middle, the computer plays to the next corner and if the user plays to the corner, the computer plays to the next middle).
In all other moves, if the user fails to block, then the computer plays opposite of the previous move and wins (i.e. because the user failed to block).
Otherwise, for the computer's third move if the user had played to the middle of a row in its first move then we step 1 back from our previous move and win. (That's our other winning case). That's because the computer's second move always creates a dual two-in-a-row where the previous location is its other winning choice.
Otherwise for the fourth move then we backwards by 2 and it's a draw.

It's a really simple strategy, which if you note, doesn't involve responding directly to the user's moves, except to record whether they first played on an odd or even square or whether they last blocked the computer's move.

In Forth we can simplify it by representing the moves as a table, one set for when the person played to an even-numbered square and the other set for when the person played to an odd-numbered square:

cdata compMoves 1 c, 2 c, 7 c, 0 c, 1 c, 2 c, 3 c, 6 c,

And then the algorithm simplifies to:

If the user didn't block or we haven't played yet, then pick the next move from the table adding it to our current position and if the move was '7' we win, else if it was a '6' we draw.
Otherwise we move to the opposite side of the board to our last move and win.

In Forth this is:

: compPlay ( movnum comp h -- m c f )
dup opp + brdRange = ( m c h h+4=c )
>r over = r> or if
  over compMoves + c@ dup >r + r>;
  7 =
else
  opp + 1
then
;

An entire oxo game in approximately 9 lines of code! The entire game is listed on the FIGnition website and also here. It takes up approximately 5 screens and 554 bytes.

( Simple oxo )
: 2drop drop drop ;

: .brdLine
cr ." -+-+-" cr ;

: . Board
." 1|2|3" .brdLine
." 8|X|4" .brdLine
." 7|6|5" ;

4 const opp
64 15 + const (o)
64 24 + const (x)

: cdata <build does> ;

0 var board

cdata posConv
0 c, 0 c, 1 c, 2 c,
5 c, 8 c, 7 c, 6 c,
3 c,

: pos2xy posConv + c@
  3 /mod 1 << swap   1 << swap ;

: place ( pos ch -- f )
over 1 swap << board @   swap over or   2dup =
if ( pc old nu )
  2drop 2drop 0
else
  swap drop board !
  swap pos2xy at emit  1
then ;

: range? (val lo hi --     val | 0 )
rot swap over <
>r swap over > r>
or if drop 0 then ;

: humPlay
  0 begin drop
   begin
      key 49 57 range?
   dup until
   48 - dup (o) place
  until
;

: brdRange 1 - 7 and 1+ ;

cdata compMoves
 1 c, 2 c, 7 c, 0 c,
 1 c, 2 c, 3 c, 6 c,

: compPlay ( mv c h ..)
  2dup opp + brdRange =
  >r over = r> or if
   over compMoves +
   c@ dup >r + brdRange
   r> 7 =
  else
   opp + 1
 then
  over (x) place drop
;  ( .. -- mv c f )

: init 0 board ! cls .brd
;

: win? 5 0 at
  ?dup if
     ." I WIN!" key drop 1
  else
    over compMoves + c@ 6 =
  ?dup if
      ." DRAW!" key drop 1
  else 0 then then ;

: oxo
  init humPlay dup 1 and
  4 * swap dup
  begin
   compPlay win?
  0= while
      swap 1+ swap humPlay
  repeat
  2drop ;

In a future post I'll look into a more sophisticated (2Kb!) version of noughts and crosses: where the person can start first, where I use real UDGs for a full-screen display and where the computer can LOSE ;-) !

Arctic Smashed

2011-07-18T10:08:00.005+01:00

I've been doing some simple analysis of the arctic sea ice extent data in order to generate my own prediction of the summer low. I'm now almost entirely convinced that the 2011 record will be smashed in 2011.

I've based it on the Jaxa arctic data from 2002 to 2011, which I imported into a gnumeric spreadsheet. You can see from the initial image that the SIE for 2011 is below the record-breaking year 2007 and has been every day since mid-May. In itself, this should be cause for alarm, but let's go back to 2007 to see why it's even worse than you might think.

2007 was a record-breaking year, but it didn't look that way until it lurched into free-fall in the last 10 days of June, due to a 'perfect-storm' of (AGW-induced) weather conditions, which set the scene for a record loss in late September. So the fact that 2011 has been lower since May isn't conclusive.

So, what I did was take the Jaxa data an import it into a spreadsheet. My first estimates were based simply on the ice loss from previous years after July 16 bolted on to July 16, 2011. There I discovered that the SIE minimum for this year would be about 4.16million KM2 - a new record, but not by much, a mere 80,000Km2. What's scary though is that simply bolting on the curves means that we'd get a record for 7/9 of the previous 9 years.

July 16: 2011	7347656
Year:	2010	2009	2008	2007	2006	2005	2004	2003	2002
Minimum:	4813594	5249844	4707813	4254531	5781719	5315156	5784688	6032031	5646875
July 16	8025000	8342969	8423438	7592500	8079844	8401094	9029375	8858281	8832969
Simple Prediction:	4093125	4199219	3549219	3911874	5024844	4174218	4058906	4426406	4077187
Average:	4168333

But it's not a realistic estimate - it's likely to be an underestimation. That's because SIE curves tend to have some continuity between the current state (and conditions) and the future state. So I constructed a slightly better estimation. In this one, I calculated the slope of the ice loss from July 1 to July 16 and compared the ratio with the eventual ice-loss at the minimum SIE for every year.

July 1 to July 16:	1715157
Year:	2010	2009	2008	2007	2006	2005	2004	2003	2002
July 1-July 16:	781563	1379844	1221562	1696406	1158750	1214375	1031250	1108750	1210937
Ratio to min SIE	5.11	3.24	4.04	2.97	2.98	3.54	4.15	3.55	3.63
July 1-16 Extrapolated:	3.002E+05	3.503E+06	2.131E+06	3.973E+06	3.946E+06	2.989E+06	1.951E+06	2.976E+06	2.835E+06
Average:	2.734E+06

With this, the best-case projection (i.e. maximum minimum SIE) will be 3.95million Km2 and the worst case will be 300,000Km2 (average 2.7million Km2). That's - stunning, and stunning doesn't even cover it: a 50% ice loss from 2007 in the best case, a 93% ice loss in the worst case, 33% ice loss in the average case.

The question is then how reliable these estimates are. Well, I'd be the first to say, "not very". My projections can be skewed easily by a steep anomaly in early July 2011 which would project a much lower summer minimum than would be likely.

The irony is that 2011 has had a smoothly falling curve between May and mid-July and it was 2007 which had the sudden acceleration over July. So 2007 makes my 2011 estimate look higher than it's likely to be. So, I'll stick my neck out at this point and say I figure the arctic record will be smashed this year, it's likely to be around 20% lower than 2007, probably in the range of 3.5million Km2, almost certainly lower than 4.0million Km2 and perhaps even as low as 3.0million Km2.

Flashy FIGnition!

2011-07-01T12:26:00.006+01:00

I'm the designer and developer of the FIGnition DIY 8-bit computer from nichemachines and I'd like to share a major milestone in its development with you.

FIGnition contains 512KB or 1Mb of raw Amic Flash storage. I've been working for quite a while on making the chips work like a proper disk, like USB memory sticks do and at last it appears to work and this is a momentous achievement!

Making Flash work like a proper disk is hard, because Flash memory is a development of an old technology called EPROM, which could only be written once and then required sitting under a UV light for 20 minutes to re-initialise it all (losing all the previous data). The only difference with Flash is that you can erase it electronically. Using Flash memory is like trying to write a book with an old mechanical typewriter and without tippex, but with a portable recycling unit. Every time you make a mistake on a page or need to change it you need to pick up a new clean page. Moreover, you're not allowed to change the orders of pages so you'd end up with all the page numbers in the wrong order. It's one redeeming feature is that you can take 16 or 32 consecutively edited pages and stick them through the recycling unit to give you new clean pages.

If everyone had to type like that I figure no-one would have ever bothered.

But that's how Flash is. On the (easier-to-use) Amic chips you can write a block of up to 256b at a time ( a page ), but you can't rewrite it; and you can recycle 16 pages at a time.

This FIGnition firmware is therefore so amazing it needs a blog of its own. As far as I know it's the smallest virtual flash disk software around at only 1.5Kb of compiled 'C' code (on an AVR Microcontroller). The firmware abstracts the Flash memory so that you can read and write 512b blocks to your hearts content; it remaps them to physical flash pages on the fly and recycles all the modified pages. The algorithm is so short you could port it to the internal Flash memory of a Microcontroller and use it as a proper disk and could be converted to work with as little as 4 original 28F010 devices (128Kb drive) (or 1 AMD 29F010 device (80Kb drive)).

To give you an idea of how good this is, it's worth comparing with existing uses of Flash chips. Most standard introductions to the embedded use of Flash memory tell you to create the memory image on the host and simply write it to the target. AmForth, for example uses internal Flash memory to store programs, but if you make a mistake you have to erase the lot again: you can't Forget definitions. Butterfly basic (for the MSP430) is similar, you can write and edit over individual lines of code, but once the Flash is all used up (even if there are reclaimable areas of flash) you have to erase the lot. UCLinux (a fairly complex embedded OS) can either use the rather large MTD flash driver or be restricted to the write-once blkmem driver. The original Psion SSDs on both the Organiser II and Psion 3 systems (both far more complex than FIGnition) used sequential, variable-length records and you had to copy the entire SSD to another one when it ran out.

VDsk FIGnition's VDsk flash system is also a bit of a 19 year personal dream. In the early 1990s I was working at a embedded company called Micro control systems where we developed solid-state storage systems using the then brand-new Intel 28F010 Flash memory chips and a bit later, the early PCMCIA flash cards. They were MS-DOS based systems and you could prepare MS-DOS formatted disks in a sort of write-once procedure. I spent quite a bit of time working on a truly general purpose flash disk system, which could have appeared at the same time as the first San-Disk Flash disks. But it was never in the company's commercial interest, so it could never be justified.

Later still, I worked at Teleca.com where we base-ported Symbian OS (Nokia and SonyErricon's Smartphone platform in the early 00's) to new phone hardware. The Flash drivers were good, but formidably complex! Inbetween I toyed with variants of simple Flash filing, either targetted at an old Apple IIc or ficticious embedded systems.

But now it's done - a simple, purging, embedded Flash Disk system which supports wear-levelling and is reasonably robust in the face of sudden power failures. It's been tested for over 60,000 block re-writes (30K on 2 different device types) with no errors. Enjoy.

It's Good To Ask Questions

2011-06-08T20:10:00.004+01:00

On facebook my cousin Benjamin shared a reference to an article in an Irish newspaper about her deconversion to Atheism and asked "I'd like to see a theist's take on this article."

So, I thought I'd take him up on it. Hope the response isn't too dry! First it'd be a good idea if you read her article - it's well written and gets to the point.

“Atheism Is the True Embrace of Reality”

Paula's article consists of two major points.

Firstly: she explores the variety of Christian beliefs and finds them completely inconsistent. Therefore you can't know anything about the truth of the existence of the Christian God.

Secondly: Atheism isn't a belief, but a rejection of beliefs not based on evidence.

The first point is essentially an argument from subjectivity. I.e. a subjective experience can't tell us anything about the existence of God. And that's kind of correct, a subjective experience isn't a basis for even determining God's existence, never mind his/her/its properties or character. And that's primarily because from an external viewpoint (which is what the observer has), the subject is simply another item within the reality we live in: a heap of well-organised DNA, generating sound waves.

The problem therefore with the argument is that it's the wrong way round. God, if he/she/it existed determines us and our reality, in a roughly analogous way to the way mathematical axioms determine valid mathematical theorems, or (going another step back) a mathematician determines the set of axioms, which then determine mathematical theorems. It's not possible to determine God's existence from subjectivity in the same way it's not possible to determine the historical existence of Euclid from the existence of parallel lines, not even if the parallel lines could say "I wouldn't be where I was today without Euclid!" ;-)

So, the problem remains, if subjectivity isn't a valid basis for believing in God's existence then what would the basis be?

So, onto the second point: "Atheism isn't a belief, but a rejection of beliefs not based on evidence". So, the questions I would raise are firstly: What is precisely meant by 'evidence' here? Secondly: Is evidence a sufficient basis for beliefs?

I suspect that what she means is scientifically attested evidence supported by a consistent rationale (although she doesn't really mention anything at all about the need for reason in connection with evidence in her article). What she doesn't mean is subjective evidence, i.e. "I went on a milkshake diet last week and lost 2Kg", even if the person could prove that they did go on a milkshake diet last week and lose 2Kg.

The issue in her part of the argument is that all her qualifying terms, such as: 'valid' (as in "a deity for which no valid evidence…") or "reality" (as in "one you have faced up to the reality that there is no evidence") end up being circular. What is 'valid' means (I presume): "scientifically attested" (i.e. attested, because repeated experiments have provided consistent evidence). What "reality" means is: the reality one can infer from valid evidence and reason, etc.

With her second point the problem again is that "evidence" can't be a sufficient basis for beliefs. Let's consider one of her statements: "there is no evidence to suggest there is another life after this one, it becomes all the more important to live this finite life to the full, learning and growing, and caring for others, because this is their only life, too.."

But this doesn't follow. If there's no life following this one, then why not just stomp on everyone else to get your own way? We're both going to die after all. Or putting it slightly differently: there's no life after this one, so why not just try and make as much money as possible? There's no life after this one so why not just party? There's no life after this one so why bother getting up in the morning? All these things, I think, follow just as well don't they?

Conversely, what if the evidence proves unpalatable ideas - should we change our beliefs? What if objective evidence in the end justifies genocide - that is that unless we bump off the weaker members of our society (e.g. religious people) then humanity is doomed. What comes first in that case?

So, as I see it, the nub of the problem is the question of what counts as a sufficient basis for anyone's beliefs on any kind. Subjective claims aren't a sufficient basis for knowing truth, but 'evidence' is a badly defined term and a complete minefield as a basis for constructing beliefs about how to live.

But it's good to ask questions isn't it?

Carjacked Honeymoon

2011-04-21T09:03:00.002+01:00

I guess most of you already know what happened to us in brief. I thought it would be a good opportunity to write down the current situation as it's too long for a facebook status.

Anyway, this is what happened. We arrived in Naples on April 18 in the evening, about 20:35. We picked up the hire car, a basic Fiat Panda without SatNav. It took us 90minutes and I had to get an overdraft extension just to be able to pay for the excess which hadn't been specified on the form. And then we started to try and navigate our way out of Naples in dark.

Except it just wasn't easy at all - the main highway to the A3 which would take us to Sorento was blocked so we ended up going round half of Naples and in and out of the airport for thirty minutes before we found a street which sign posted a turning for the autostrada.

While we were trying to figure out whether the turning would take us in the right direction a motorbike pulled up on our left; the back passenger got off and came up to the car. I can't remember too clearly what happened next as it was a bit of a blur. The guy was gesticulating and shouting and when I expressed my confusion I saw he had pulled out a pistol and cocked it into position (by pulling the top section back, it was an automatic).

I got out of the car and wandered over to the other side of the motorbike; I saw the other guy get in as Helen got out and the first guy started pointing at my wedding ring (a fairtrade gold ring, one of the first that could be bought that way) and when I refused put his hand in his pocket to pull out a gun...

but before he could do anything a car appeared round the corner and they both sped off, leaving us without our car, clothes, money, cards, Kindle, passports etc. They took everything except the clothes we were standing in; our rings and mobile phones, only one of which had any power.

So then we spent the rest of the night stuck with the police. The incident took place just outside a house, and the occupants let us in after they saw Helen calling for help. With the help of Yahoo Babelfish we were able to explain something of what happened; they called the police (5 officers arrived); and after 90minutes where precious few details were taken we went to the main police station to take down a statement, but just ended up waiting so long we were then escorted to a hotel for the night (pre-paid for by Helen's friend Mary), where eventually the hotel managers let us in (they wanted to see our documents... which of course we didn't have).

Mostly we've been spending the rest of the honeymoon trying to get enough things into place, but it's all so terribly involved. It took a whole morning to get a fairly simple statement down. We now have some changes of clothes, a temporary passport and a little money and we've spent 2 nights in our hotel. We have yet to sort out what happened to the car and other things it's probably not best to go into details with on this blog.

However, we are completely unhurt, we must emphasize that. Many people have been very helpful, we'd like to thank the British Consulate in Naples for their extended help along with the kind support of the staff at our hotel as well as other sympathetic individuals. Thanks for all the support from all our friends, I hope this blog helps you know where we're up to.

Much love from julz and Helen

Televisors!

2010-12-06T13:46:00.004Z

This is just a short - scruffy post about Televisors. A friend of mine pointed me to the MUTR website which is selling minature Televisors and it set me thinking about variations on the theme. But first some information on the Televisor frame format.

Frame Format

There are variations on the Televisor format, but here's a summary of the MUTR one.

Frame rate is 12.5Hz.
There's 32 vertical scans so each scan is 400Hz.
The original doc specifying the minature Televisor specc'd the pixels frequency at 80 pixels per scan, so each pixel is at 25.6KHz.
Voltages are similar to composite TV: 1V peak-to-peak is normal. Sync is at 0V, black is at 0.3V, white is at 1.0V.
Frame sync is the entire 32nd scan - so the 32nd hole on the disc is used to check frame sync.
Line sync (here vertical sync) uses the bottom 7.5% of each scan, the bottom 6 pixels. So, there are 74 video pixels available.

That about sums it up, now for the ideas:

Visorpong

It should be possible, just using nearly the lowest MCU available ( e.g a PIC 12F509) running at 4MHz to implement pong, producing televisor video output. Here the PIC generates up to 78 pixels per scan; that's 32 clocks/pixel with 5.8 sync pixels. I worked out a basic output routine:

btfcc TMR0,0 ;(btfcs for odd pixels).

goto .-1

movf gGpio,w

btfsc 0x10+(pix/8),7-(pix&7)

addlw 1 ;bit 0=video signal.

movwf GPIO

Which takes 6+3n where n is the number of wait loops, so we have up to 26 c for computation; about 1872 overall. There's up to 10% jitter on pixel output. There's also 196 cycles available during sync.

Digital Televisor

Similarly a more highly-specced MCU, e.g. an AtTiny25 should be able to sample incoming Televisor video and control a real Televisor disc and output video onto it. This would greatly reduce the part count and the MCU would also be able to do automatic line and frame sync.

Televisor Simulation

You don't need a 75MHz Pentium to simulate a Televisor - a ZX Spectrum with an analog in would (just) be able to keep up with converting Televisor input onto its screen, my draft routine uses 75% of CPU converting samples into dithered bitmaps, here's the core of it:

in a,(sampler) ;10c?

out (sampleTrig),a ;start next sample (data is irrelevant). 21

add a

ld e,a

ld a,(de) ;first conversion sample.

inc e

ld (hl),a

inc h

ld a,(de) ;second conv sample.

ld (hl),a

inc h

I've been trying to think about how a VIC-20 could keep pace; running it in 16 chars x 20 lines with 4x2 VIC-20 pixels per real pixel, but my best basic routine so far would take 38cycles, about 20% too slow.

NSXMLParserDelegate fix for different iPhone iOS versions

2010-09-20T14:04:00.003+01:00

This is a short blog providing a better fix than I've yet seen for supporting consistent NSXMLParserDelegate code across different versions of iOS.

The problem occurs because the NSXMLParser class was changed between iOS 3.0 and 4.0. Originally it informally declared some delegate methods and this was turned into a formal delegate protocol: NSXMLParserDelegate.

This means that you'd need to fake the delegate class with:

@protocol NSXMLParserDelegate
@end

if you're compiling for a iOS 3.0 target, but this will generate a duplicate @protocol declaration warning if you then compile for after 4.x. So, really you want the protocol declaration only for versions of iOS below 4.0.

The easiest way to do this is simply to wrap the protocol declaration with:

#ifndef __iphone_4_0
@protocol nsxmlparserdelegate
@end
endif

That's how you test for the current SDK version - in any particular sdk there's a #define for each version up until the current version, so version 4.1 has __IPHONE_

-cheers from julz

British Christian Doctors aren't killing enough patients

2010-08-27T07:04:00.003+01:00

In one of the strangest BBC articles I've seen in ages, the BMA has complained that Christians are more likely to prolong the life of their patients by suggesting pallative care - and that's a BAD thing, because everyone should be a functional Atheist at work.

In this weird and rambling article, the BBC claims (conflictingly) both that Christian doctors should leave their principles at the surgery door, and work in a purely dispassionate, objective way and also that they should have their patients interests at heart.

I thought doctors were supposed to be following the hypocratic oath, which is primarily concerned with doing good and at the least, not harming the patient.

This does rather all smack of secular propaganda, for example, it's an article attacking religious people, but no viewpoints of Christians are offered, so there's no balance. It does however put forward 'Dying with dignity' agenda across, a pro-euthanasia organisation. It also uses the way in which the secular industry's pro-death media campaign has shifted public opinion over the decades (by publicizing a number of cases of people who want to die) to then put the pressure on Christian doctors.

The reality is that one's beliefs (or lack of them) actually do influence a person's professional conduct, because they influence one's ideas and goals. This is true for religious people and secular people. There's no neutral setting and defining oneself as being neutral doesn't change that.

Climate Change Weather Index

2010-08-15T09:06:00.003+01:00

One of the biggest issues with assessing climate change is how we link climate with weather. We know that climate change ought to produce a corresponding change in weather patterns, but we can't demonstrate that individual weather events are a product of climate change and in the minds of most people weather is what we see (natch), not climate.

So, although the Russian president attributed the recent heatwave to climate change, even New Scientist are far more cautious in doing so.

I think the way to resolve this is not to look for demonstrations of extreme events, but to relate all weather events to climate change. This is how:

Essentially, if climate change is being driven by global warming then what we're saying is that there's more energy present in the earth's system, because heat is a measure of energy and temperature is: ºC = J/(Kg * SpecificHeatCapacityOfAtmosphere).

Extreme weather events are powered by the extra energy in the system. So in a sense all we have to do to relate weather events to climate change is calculate (even roughly) the energy in any particular weather event and add it all up. We can then provide a total and a probability that this total thus far lies within the natural variance. We make these two figures part of normal weather forecasts.

This technique will work well for relatively local weather as well as global weather and as weather events add up to a convincing argument for climate change people will want to see the Climate Change Weather Index falling - they'll want to do what it takes to reduce flooding, heatstrokes, air-conditioning and blizzards.

Death Throes In The Arctic

2010-06-04T14:37:00.002+01:00

Be prepared to be shocked, the Arctic is seriously likely to reach a record-breaking low extent this summer. I thought I'd write a short blog on why; and why I think the arctic is in its death throws.

This year's Arctic record low will be easy to understand. We're predicted to have a record-breaking ground and sea temperature; we've had record breaking increases in CO2 (3ppm in a year, during a recession I might add); the ice volume anomaly has already broken records by about 100% (compared with 2007). The ice-extent itself declined from a near 1979-2000 average in early April to below the record low for this time of the year (which occured in 2006) so if it tracks at the same rate it'll take until July at the earliest before 2007 catches up. However, it will almost certainly accelerate.

So far so bad, but actually it's much worse. Climate Scientists have been predicting imminent new record lows since 2007, because the 2008 and onwards Winter ice has been thin and therefore prone to melting - so the ice extent over the past few years has been deceptive. In fact summer 2008 and 2009 were almost as bad as 2007 and it should have been newsworthy even though it wasn't terribly surprising.

The real killer though isn't the thin ice, but that so much of the Arctic ice is no longer solid, but broken regions of ice held together by refreezing - rotten ice. There are numerous first hand reports confirming this; that is, detailed satellite picture analysis and fly overs. I think we should now consider the Arctic to really be basically a mass of loosely connected ice-floes primed to float south at the slightest provocation. This 'ice-mass' is moving quickly as some Arctic explorers recently found out.

That's the problem - the Arctic ice no longer even needs to melt as such, it can just drift into oblivion.

Someone beat us to it!

2010-05-04T23:29:00.003+01:00

Did anyone ever tell you what happened to the great ancient library of Alexandria? It was like a major wonder of the world and held so many classic texts that its destruction precipitated the half-millenium long Dark Ages. I've spent roughly 22 years under the unhappy impression a mob of brutal, ignorant Christians burnt it to the ground for the crime of being heretical. It turns out someone beat us to it.

By centuries.

You can read the entire story here. The point of this blog isn't really to shift the blame though, but my story of this story - how I kept coming across this myth and how different & more complex a more accurate history is.

This is how it goes. In my middle childhood to mid-teens I embraced Atheism, consciously understanding what it was about and genuinely valuing how science and reason had helped humanity progress beyond religion (as I understood it then). Part of this meant I was really into popular science literature and this is where I came across the story via the otherwise brilliant book Connections by James Burke. I've summarised it above, but the basic idea is that the late 4th century Christians, being opposed to reason and knowledge burnt it down in a riotous act of wanton vandalism, because esp, the Librarian was female.

At the time that made sense to me and I guess I internalised its point, but by the time I was doing my PGCE in 1990/1991 I'd become a Christian and forgotten it all; so I was quite shaken when a rather angry Atheist on my course launched into a tirade on the concrete walkways of UEA, using this an a prime example of why he really couldn't stand Christianity and Christians.

OK I thought, well Christians are perfectly capable of messing up badly. So the (indirect) shame stuck with me for about 10 years until I found myself on the Anvil Workshop course in 2001. Here I got a slightly different version of the story where the riot was caused because the female Librarian had moved the Library to a pagan temple (which the Christians wouldn't visit).

And that's still pretty bad and yet on this course I learned a few things that didn't quite add up. Firstly, many of the early Christian leaders had had their theological training at Alexandria and so were well versed in Classic literature. Secondly, the Septuagint (an ancient Greek translation of the Old Testament often quoted from by the writers of the New Testament) was translated at Alexandria too. It doesn't make quite so much sense for these types of people to want to burn it all down.

I should have started questioning the story a few years later when I found out that the Christianisation of Ireland beginning with St. Patrick (a real person, who never drank Guiness ;-) ) resulted in generations of Irish Christians who made the acquisition, preservation (and reading) of ancient literature a high priority. These amazing people were responsible for maintaining the majority of all such texts Europe had access to until the influx of books from the middle east after the Crusades.

I kinda just assumed they'd got them from elsewhere. It turns out that the history is both simpler and more subtly complex. To put it simply: Christians didn't burn the Library, it's a myth. More subtly, they couldn't have, because Alexandria had multiple libraries.

It's actually a conflation of stories. Alexandria had been burned down in ancient times, but not by Christians - Julius Caesar had accidentally done it in 48BC during an attack on the port. What the Christians did burn in AD391 were the Pagan temples by decree of Emperor Theodosius and although one of the temples had been used as part of a library there's no record of whether there were any books left in it by then.

So, our predecessors appear to be innocent on this particular count - jolly good :-) ! So what happened to all its books during the Dark Ages? Come to think of it, what happened to the Dark Ages? - I've heard contemporary historians figure that's a myth too ;-)

Typewriter Hacking

2010-02-17T17:16:00.006Z

There's been some recent interest in typewriter hacking. Some guys figured out how to hack a Brother SX-4000 electronic typewriter so that you can turn it into a printer. They do it by simulating key presses on the keyboard matrix using a microcontroller.

I think I can go one better with the Smith Corona SL470. The SL470 was an early 90s electronic typewriter with some facilities for tabs, word wrap and word correction. It's based on a daisywheel printhead which made me think that it might be possible to turn it into a simple printer. SL470s can often be found on ebay.

But why? Well, the major reason is because of my interest in retro-hardware. Libby8 for example will be a computer with only 26Kb of usable RAM so hooking up a printer (if I ever did) would mean hooking up a simple printer, because I wouldn't be able to fit in a driver for a modern USB printer.

I opened up the typewriter. The hardware is amazingly simple and the circuit is fairly minimal. Basically it's all controlled via an Intel 80C52 Microcontroller (the big chip on the left) and a few buffers. The cables at the top control the various LEDs; carriage and daisywheel print mechanism.

The keyboard ribbon is on the right and I spent a bit of time trying to map it. It looks like it'll be a normal matrix keyboard, but it's not. After 30+ mins of work I only managed to figure out the left-hand side. The other side (which certainly works) isn't so straight-forward it seems.

The 80C5x series were very popular MCUs from the 1980s and 1990s. Like many MCUs they have terribly awkward architectures, but hey - you can get them to do some work. This one has 8Kb of ROM and an internal 256b of RAM - which is why its word-processing features weren't that great (no RAM to store more than one line of text in).

I had a hunch that if I'd built the typewriter I'd use the same circuit for both a simple typewriter and a typewriter/printer. In fact when you open the case it looks like there's a gap on the left for a suitable expansion circuit. The 80C52 has a built-in serial port, so when I downloaded the 80C52 manual I took a look at its serial pins; which are pins 10 (RXD) and 11 (TXD). I found out that these lines had special tracks on the PCB that lead to pins marked H5 and H6 which aren't connected to anything.

It looks to me like my hunch might be correct to some degree. The SL470's serial port might be used for something... :-)

God Loves Green

2009-11-13T10:24:00.002Z

Introduction

It should be obvious that God loves green, he made so much of it. So why is it that a significant number of Christians figure that trying to combat Climate Change is against his will?

This is an admittedly long blog exploring the question as it applies to the book of Revelation. Revelation is always a minefield when it comes to making pronouncements and like the many other people who have rather bizarre interpretations of the book I’m similarly unencumbered by a theology degree; though unlike many I’m also lacking in the milleniumism department.

Assuming that someone actually reads this blog who doesn’t know the Bible very well - Revelation is the last book in the Bible and rounds it off in spectacular style, with a grande conclusion where everything’s sorted, shiny and perpetually new. It’s the bit in between that causes all the controversy. Despite what many people think, Revelation isn’t a complete bloodbath: the first three chapters are mini letters to actual 1st century churches in Turkey and the last two are the happy finalé. Amongst the remaining 17 chapters only Chapters 6, half of 8, 9, half of 11 and 16 have an apparent bearing on the subject. And to cut to the chase, one verse stand out in terms of clarity with respect to God’s judgment:

“...The time has come to reward your servants, the prophets, and all your people, all who have reverence for you, great and small alike. The time has come to destroy those who destroy the earth.” Rev 11:18b.

We'll need to look at a number of facets of the Bible to show why this is the case.

Scripture Interprets Scripture

OK. What this means is that you shouldn’t jump to conclusions about verses in the Bible until you’ve grasped the whole thing. It’s a bit of a chicken and egg situation, but it’s helped because some parts of the Bible are clearer than others. For example, the Bible certainly does say “God Is Love” - ( John’s first letter, Chapter 4, verses 8 and 16). The Bible also says God gets angry (e.g. Romans 1:18). Since the Bible never says “God is anger” we conclude that God’s anger is secondary to his love, and moreover, it should be understood in the context of him being Love itself. The Bible itself confirms this when it says in several places:

“The Lord is slow to become angry and full of constant love” (e.g. Psalm 145 v 8).

So it’s not wise to apply isolated verses, for example even my quote of Rev 11:18b above, unless the verse somehow fits into the general flow of the Bible. So, if the Bible claims God thought it was a really good idea to create an amazing universe and earth then even verses that appear to talk about God wanting to destroy it should be read cautiously.

Revelation Is Highly Symbolic

Of all the books in the Bible, when it comes to the book of Revelation, we have to tread carefully, because it really is very symbolic. For example, in Chapter 1 v 16 Jesus is described as having a sharp two-edged sword coming out of his mouth. The writer (John) isn’t saying that Jesus is gagging because of a dangerous obstruction. He’s merely expressing the power of Jesus’ voice. Later Jesus’ voice is described like a powerful waterfall. It doesn’t mean John felt like he was being deafened by crashing hiss and couldn’t make out what was being said. Similarly, chapter 12 is about a woman, a son and a Dragon. It’s very weird with the dragon throwing 33% of all stars from heaven; trying to kill both her and her son and them being whisked away from danger. Actually, it’s a highly symbolic description of the Good News of Jesus. Relax, it’s happened.

But just because it’s symbolic, it doesn’t mean it’s just useless and confusing. It’s really like that to inspire and encourage - you might think your life is pretty humdrum, but from God’s perspective it’s all completely wild!

Not Everything That Happens In Revelation Is Done By God

Let’s look at a bit of Revelation that’s all about destruction. Chapter 6 is about four horsemen. What happens is that the ‘Lamb’ (a symbol for Jesus) opens five ‘scrolls’ and four horses and riders pop out and cause havoc: War, Taxes (maybe), Death and Martyrdom. The last scroll causes lots of devastation: the sun goes dark, the moon goes red; stars fall out the sky and the sky disappears.

So, assuming this is a prophecy about actual earthly devastation (which it might not be), then does it mean that Jesus is basically killing everyone and wreaking the planet?

No. And this is why: because the fifth scroll represents martyrs and Jesus certainly doesn’t kill his followers. My personal take on it is this: Jesus’ opening sealed scrolls (which in ancient times typically contained proclamations) means Jesus is simply revealing things; not doing the things that are being revealed.

Similarly, in Chapter 8, angles blow trumpets and all sorts of ‘earthly’ disasters happen. For example:

“Hail and fire, mixed with blood, came ouring down on the earth. A third of the earth was burnt up, a third of the trees, and every blade of green grass.”

Nasty. But again, none of this is attributed to God in chapters 8 and 9. Instead these things happen after an Angel (which means “God’s messenger”) blows a trumpet (“i.e. makes an announcement). The latter part of chapter 9 is about disasters that fall on people via human/horse-looking locusts headed by an ‘angel’ king called “The Destroyer.” I’d hazard a guess, but with a name like “Destroyer” this king and henchmen are probably not on God’s side. And in any case it’s centred on people, not the ecology (in fact in v4 the ‘locusts’ are told not to harm plants, only people).

God’s Anger Isn’t Like Ours

Even when God is angry, it doesn’t necessarily mean he’s acting directly - he may be acting through someone or something else. And it doesn’t mean that if he’s acting through people that these people are God’s faithful people.

For example, let’s look at Jeremiah 25. Jeremiah takes place during the reign of the last kings of Judah (the ‘better’ half of Israel) and covers the destruction of the country, primarily through the Babylonian king Nebuchadnezzar. In chapter 25 we read this (from v9):

“I am going to send for all the peoples from the north and for my servant, King Nebuchadnezzar of Babylonia. I am going to bring them to fight against Judah and its inhabitants and against all the neighbouring nations. I am going to destroy this nation and its neighbours and leave them in ruins for ever, a terrible and shocking sight.”

Here, Nebuchadnezzar is called God’s servant. But it’s clear from other Old Testament books that he isn’t one of God’s people - he acknowledges God sometimes, but basically he’s a ruthless pagan tyrant. He’s not one of the good guys, he doesn’t live an exemplary life, you wouldn’t want to meet him.

So, God sends Nebuchadnezzar to invade Judah, but the commands he gives to Judah aren’t to join or support the Babylonian army or act like them. Instead we read, a few chapters earlier:

“The Lord told me to go to the palace of the king of Judah, the descendant of David, and there tell the king, his officials and the people of Jerusalem to listen to what the Lord had said: ‘I the Lord, command you to do what is just and right. Protect the person who is being cheated from the one who is cheating him. Do not ill-treat or oppress foreigners, orphans or widows; and not kill innocent people in this holy place. If you really do as I have commanded, then David’s descendants will continue to be kings...’” Jer 22:1-4a

The only way to take this is that God’s punishment is to allow evil people and their forces to destroy Judah for their failure to be just and right. So, the people who bring the disasters are destructive (and wrong) and the solution is to act justly, righteously and lovingly.

In the modern context, surely it means this. If as Chapter 16 implies, God has an ultimate intention of bringing environmental disaster then those who bring it - i.e. those who cause environmental damage are themselves the bad guys, not God’s people, i.e. the equivalent of the ‘Babylonian Army’.

Furthermore, God’s commandment to us is to act righteously. At the time, it wouldn’t have been an excuse to say “Well God is sending the Babylonians to trash the place so I might as well grab all I can and dispose of anyone who gets in my way while it’s possible.” In a similar way it’s not acceptable to say “Well God is sending an environmental disaster, so I might as well buy a new SUV, invest in ExxonMobil and go on yearly holidays to Mexico.”

In this sense God is acting like a Gaia hypothesis. The Gaia hypothesis treats the earth as a living organism, which acts a reassert its survival if threatened. In this case we threaten the earth and so Gaia would bring disasters in order to eliminate the threat - the important thing being that the organism survives, even if we don’t.

I’m not sure that Chapter 16 of Revelation (the 7 bowls of God’s anger) applies in our near future, even if you read Revelation as actual predications of the future. There’s two main reasons: firstly, since we don’t know when Jesus returns we don’t know when any of this other stuff would happen either. Secondly, when it happens may be conditional on our behaviour, as in Jeremiah 22. For as long as we act justly, it won’t happen.

Conclusion

We have to be careful about how we interpret the book of Revelation - it’s symbolic for precisely that purpose. If we take a consistent look at what God is like and how we’re supposed to be then we find that what is there makes sense and holds together. God loves us yet detests people abusing his creation. If we push him far enough though he can relent - allowing disaster to fall, even allowing it through the actions of evil people and systems. In the end though, as it says in Rev 11:16b:

“...The time has come to reward your servants, the prophets, and all your people, all who have reverence for you, great and small alike. The time has come to destroy those who destroy the earth.”

God, right now, wants us to combat climate change. Over a period of 250 years we’ve transformed our society from largely agrarian to highly industrialised. 19th century Christians saw the implications of industrialisation and fought hard for better living and working conditions for its victims. It’s time for us to take this baton of God’s love and carry it into the 21st century.

In part 2 I’ll look at some of the practical consequences of what’s actually happening here and now. I’ll be looking at why compassion for South American orphans, Ghanians in shanti towns; Bangladeshis, Sub-Sarahan Africans, Assamese Indians means caring for the planet and why God’s healing is so much more than just a Band-aid on a near-fatal wound.

And they’ll be more pictures!

Sinclair vs Acorn Footsoldier Memoirs

2009-10-09T15:24:00.006+01:00

Watching BBC Four's Micro Men last night took me back a few decades to when I was a lowly footsoldier for Sinclair in the 1980s. There's no doubt, the company rivalry that took place in Cambridge was mirrored in every schoolyard in the UK. And the drama was good, the BBC got the feel of the whole, crazy techwar down to a tee; from the seat-of-the-pants entrepreneurialism to the acceptability of smoking; to interspersing real 80s footage with the drama; to the personal obsessions of the rivals.

But what of the footsoldiers? Being only 12 to 15 at the time I was oblivious to the internal politics but well aware of the day-to-day conflict. There's no doubt, the rich kids got the Beebs and the scruffnecks got the Speccies. Worse still, school patronage of Acorn disadvantaged the more ordinary kids because schools often wouldn't let them do computer science homework and projects on their Speccies whereas the richer kids could do their homework on their computers - moreover, teachers would take school BBC micros home over the weekend so their middle-class kids could get extra time for free. We had to pay for our disadvantage!

OK, so how important was all this? For us, it meant something because we were developers and not just users. Our machines were platforms for our future careers where we learnt primarily problem-solving skills that would equip us for life. Consider how these 'toys' were the springboard for the British video games industry to the point where 80s kids still dominate these companies because modern children almost never learn to program. And consider how many of the younger generation of software developers still say, "yeah well I learnt to program on an old Amstrad CPC that was tossed to me in my teens..."

The true beauty and power of these machines was their simplicity - which is also what fuelled the tribalism so effectively. The Spectrum was a terrible computer, I went through 4 or 5 before I got one that worked! It had an awful keyboard; a slow BASIC language; a painful printer; chronic expansion potential and embarrassingly blocky colour. But at least it wasn't a BEEB with it's overpriced, snotty-nosed elitism; painful 6502 processor; weedy 32Kb RAM; boring motherboard and pebble-dashed casing. Yuk ;-)

If you really want to relive some of this you need more than an emulator - so why not check out Libby8dev : A spare-time tribute home micro built with A powerful Z80, RAM, Firmware and glue logic on Veroboard. Yep, I figured out how to do the entire glue logic with a single microcontroller! For only £9.99 I'll send you an AVR + firmware IC and it'll be a doddle to build. Then you can join the team and share in the world of shoe-string development with its crazy highs and lows; missed deadlines and geektastic experience full of wires, hacked circuits and solder-singed eyebrows. You also get the weekly project memoranda in courier 10-pitch!

iBook G3 Jaunty Jackalope Update!

2009-09-21T22:26:00.004+01:00

As promised here's the update for the progress on my installation of Xubuntu Jaunty Jackalope on my G3 iBook.

The basic problem was this, I have an old 128Mb USB flash stick, but it won't mount on the computer. I had had the same problems when running an earlier version of Xubuntu on my iBook and I had thought it was to do with USB Flash disk support or FAT support on PowerPC / Apple hardware. But this time, because I really like Jaunty Jackalope, I really wanted to get it working.

It's possible you've found similar problems. You plug in a USB Flash drive and it doesn't mount. You can check what it should look like when you mount by sticking in your Xubuntu installation CD (I had to type eject at the terminal to get the tray to eject) - it should pop up in the Thunar file manager window.

But with my USB Flash drive that didn't happen. After some investigation I found that the program dmesg (which logs debugging messages from the kernel) had this log at the end:

[98622.283596] sd 1:0:0:0: [sda] 256000 512-byte hardware sectors: (131 MB/125 MiB)
[98622.293940] sd 1:0:0:0: [sda] Write Protect is off
[98622.293964] sd 1:0:0:0: [sda] Mode Sense: 00 00 00 00
[98622.293972] sd 1:0:0:0: [sda] Assuming drive cache: write through
[98622.345699] sd 1:0:0:0: [sda] 256000 512-byte hardware sectors: (131 MB/125 MiB)
[98622.362888] sd 1:0:0:0: [sda] Write Protect is off
[98622.362912] sd 1:0:0:0: [sda] Mode Sense: 00 00 00 00
[98622.362921] sd 1:0:0:0: [sda] Assuming drive cache: write through

The Mode Sense bit is where it first goes wrong. It wasn't to do with file system support, because it was never able to read even the first sector. I found out from some Linux bug lists that some USB Flash drives simply don't read in Linux. I've got a good hunch as to why. It's because the testing procedure for most Flash drives probably isn't that rigorous. They test the hardware with Windows (and maybe Mac OS X) and as long as it works there they're happy.

The solution is to try another USB Flash Disk. I tried a friend's and hey presto, it worked!

So, I then tried connecting my Nokia N95 via USB and that worked, here's the image.

So, the moral of the story is: try another Flash Disk!

Jaunty Jackalope on an iBook G3

2009-09-18T01:47:00.006+01:00

Well, I managed to get an Xubuntu edition of Jaunty Jackalope to go and in the end it was pretty easy! Moreover, the experience is fantastic, it runs at a decent speed and of course it gives me access to Firefox 3 (3.0.14 as I write); which is much better than FF 2!

It's certainly fun enough to use it right now to write this blog. At first I had been having problems with a blank screen and then some stupid messages in psychedelic colours about Xubuntu running in low resolution mode and the helps I'd seen on the internet only told me to edit my xorg.conf file and that didn't do the trick. So, here's my sumarised tutorial:

First, I obtained Xubuntu from here . In my case I downloaded the CD image using Feisty Fawn on my iBook; burned the CD and then burned another CD which contained all the documents in my home directory (as I'm too dumb to stick my home directory in a special partition :-S )!

Then I found a tutorial on getting Xubuntu running on an iBook.

The key thing was getting the boot process right. The correct thing is to boot from the CD (by holding down 'c' as it chimes until you see the message telling you it's booting from the live cd). Then you press TAB and you see a list of possible boot images. You can't select the list using tab or anything like that - it's just a text message. An iBook G3 should boot from a particular image "live-nosplash-powerpc" so I literally typed:

live-nosplash-powerpc

At the prompt, then and it (eventually) booted into the graphical desktop with a messed up resolution (as I expected). But the colours were right and text was readable. Then I followed the tutorial. After installing Jaunty onto the whole disk I found the mac would boot correctly into Xubuntu with the Splash screen and it all worked OK. It made me immediately install a whole bunch of updates and then I installed the JDK so I could play around with Java Swing development on this machine.

All in all, a major success! Before you can copy my success you might need to know the specs of my machine. It's an iBook 600MHz with 640Mb of RAM and a 60Gb HD. The initial install only required about 2.8Gb; I've installed a bit more since then.

There is still one gripe - I'll come to that in a new blog, but for now the old iBook has YET ANOTHER lease of life, life in abundance :-) !

(Updated 19/09/09: Although I used the right link, I provided the wrong link for the Xubuntu download, but I've corrected it now!)

On Being Moved By Resting Bodies

2009-06-04T21:24:00.006+01:00

I took a walk round the graveyard of St. James' Anglican church in Didsbury on Sunday. Interesting place. Loads of chicken-wire type grating over most of the windows, which is a pity since the actual stained glass imagery behind would have looked so much nicer. And it seems like the place isn't totally well kempt.

I found a tomb. There's about 8 bodies resting in it and as I started to read it, it moved me. It tells a story of a 19th century family: the Bibbys from Levenshulme. It begins with Eliza, Thomas & Mary's 20 month-old toddler who died in 1803. Then there's the 1 day-old Edward who died 2 1/2 years later. And there's Daniel Burton (10) who died 15 years later aged 20 days and two other brothers: Thomas (10) and James (18) who died within 3 days of each other in 1927.

I started to think about how much grief this family had had to put up with. So many children they undoubtably loved and yet lost over such a long period. How did they carry on? Could we have done the same?

And it gets worse - Mary, their mother died in 1826; so Thomas had to endure the loss of two more sons only a year after the mother. And he himself only lasted another 9 years. I'm stunned. How did people hang on with such trauma?But then I noticed something else. Another name. At the end, Mary, another daughter (their only remaining one?): died in 1891 aged an incredible 87 years.

I think what it says is that these people had real faith in a way rarely seen today. They ploughed on when most of us would have given up. And it bore lasting fruit in the long-term - maybe Mary's descendents are around today. I was moved.

Let's Play Remythology™

2009-03-10T00:07:00.004Z

A facebook friend of mine: James Alden commented on a Independent article from March 7, 2009 where it said:

"when you sit around pretending your life is eternal and for ever, you use it casually and wastefully, like any other resource you imagine is not going to run out"

I didn't originally get why James pointed it out (he was referring to the reckless attitude within the financial sector), though the context of the original article seemed to be an Atheist take on the meaning of eternal life.

I've seen this kind of thinking before from Atheist writers; beginning with Dawkin's Guardian commentary on the 9/11 bombings. Since I've never seen anything like this idea in the Bible; nor any other Christian book or article; nor from any Christian talk; nor from my Christian friends, I'm somewhat at a loss for where the idea comes from.

Well, that's not quite true - I could see where the idea comes from if all you ever knew about Christianity was that Christians believe they have an automatic eternal life, regardless of their actual values. but it doesn't really make sense (to me) if you know even a smidgen more. If you believe God made the universe and it was a good thing, then obviously trashing his creation ain't going to thrill him too much. If you think God is serious with his commands about how to treat people with love and respect then wasting yours or others lives seems to me to be counter to his plans. If you read the Gospels you realise it's about your heart, not your excuses: signing up to Jesus isn't a licence for taking liberties which is why Paul in his letter to the Romans argues that God's grace isn't an excuse for doing wrong.

The point is, it's where your heart is and Jesus changes people's hearts. So I'm wondering what's going on here. What could it be if it's not a deliberate game of 'deconstructionism'?

My best answer is this: what if the two sides just aren't talking to each other? What if the majority of Christians have written off the Atheists because 'they'll never be able to see what the message is about' and the Atheists have given up on the Christians, because they are beyond reason? What if we're mostly just listening to ourselves imagining what the other thinks, but not actually communicating?

What if we're all playing Remythology™?

[I'll blog this for the moment and put the links in place when I can.]

Global Crunch

2008-11-21T11:37:00.007Z

This piece is intended to be a short essay on the current global crunch as I see it. I'm writing at this point, because current wisdom says that the Global Crunch won't be as bad as the Great Depression of the 1930s. Here I'm going to do a comparison between market collapses in the 20th century and the current situation. I won't say much about any predictions.

The Global Crunch is a long-term global financial crisis of whose signs had been in evidence since around 2005 and came to an obvious head in the summer of 2008. It is a direct product of unsustainable financial control; war and increasing competition for fossil fuels. Here we look at the following factors:

What to call the Global Crunch.
A Comparison with the Crash of 1929.
A Comparison with the Recession in the late 1980s.
Factors affecting the crunch.

I think inevitably, this crisis will become known as "The Global Crunch"; at the time of writing, it's variously referred to as "The Credit Crunch" or the particularly lame "The Downturn" used by BBC News.

Many of my references are taken from the Wikipedia. The 1929 Crash was a culmination of 5 years of massive stock market growth which was ultimately boosted by heavy speculative investment. The market initially recovered over the next several months of 1930, but this was not enough to prevent the subsequent Great Depression and corresponding global recessions in Britain and more importantly in Germany (where the economic (and social) instability lead directly to the the rise in power of extreme political parties and subsequently the Nazi dictatorship and World War II).

The Great Depression was exacerbated by nationalistic protectionist measures following the crash; hyper-inflation in Germany; and the road to recovery was only initiated by the implementation of Keynsian Economics in Japan; the US (the New Deal) and later in the UK to some extent. Note: Keynsian economics works on the basis that it is the flow of cash which produces wealth not the amount of it in anyone's possession. Ironically it was the World War II which propelled the US into the industrial leadership it maintained at least until the early 21st century.

The Great Depression was followed by several decades where national economics were heavily regulated by Government.

The 1987 Crash. Again, the crash of late 1980s (and the subsequent 1990s recession) can be seen as a product of market deregulation that began in the early 1980s with the Reagan/Thatcher free-market era. In this case, the UK changed its laws to allow less heavily regulated stock markets; which lead to London re-emerging as a global financial centre as financial interests moved from Europe and the US to the UK. The US subsequently started to change its regulation.

In 1986 the UK chancellor Nigel Lawson further deregulated the markets which lead to the Boom of 1987. The 1987 Crash in both the UK and US was precipitated by the large number of stocks managed by simplistic computer programs which automatically sold their shares under certain conditions - therefore since the same programs were being used everywhere, it was possible for an extremely rapid crash (actually at a far greater rate than in 1929) to take place.

In the months proceeding the crash it looked inevitable that the country would head into a recession of some kind; though the government repeatedly asserted that this was not going to happen. Of course, this was not the case and a recession did indeed follow a few years later and at it's height in 1991-1992 was responsible for a high number of repossessions from unsustainable mortgages from the Conservative housing boom of the mid to late 1980s.

So, when we come to look at the Crunch we actually see the hallmarks of previous crashes all over again. We see deregulated markets leading to a financial boom and subsequent serious bust. We see the effect of housing and mortgages on the whole financial outlook (the deregulation of the housing market in the US: the Subprime market and in the UK being very similar to that of the 80s); excessive speculation and loans (where capital / loan ratios were increased). On top of that we have constraints due to fossil fuels becoming a constraint on the economy and the undermining of the western economies by a number of unnecessary wars.

What we can predict is that this is only the start of the problem. If the past is anything to go by we can see that market collapses usually impact people for at least the next 5 to 10 years - it's unlikely we'll be at 2006 - 2007 levels by 2013 (5 years from now); it's likely that, given that economic pundits are telling us that there will be a significant recession for a few years that in fact it will be worse than in 1987 (because then they said it wasn't going to happen at all)!

I'm publishing this the day after the Dow Jones fell to 7553.8 - a fall of 46% compared with its height of 13900 about a year ago (the 1929 crash was a fall of 43% compared with its height).

Dreamstate

2008-11-06T14:12:00.006Z

On Tuesday November 5, it seemed like the US and in kind, many countries around the world entered a bit of Dreamstate akin to Britain's May 5 1997 moment, but more profound.

I know thousands of people have commented similarly, but the one thing that I am strongly reminded of is how much Obama's politics are influenced by the 60's American Civil Rights movement. In particular, MLK's (what can only be described as a literally prophetic) vision of a future America expressed in his "I have a dream" speech and book "Strength To Love".

For me, the image that most brilliantly captured the event in my mind is of the children of MLKs era: Barack & Michelle (Jan'64), Joe and Jill (June'51) holding hands at the Grant Park party.

But, it's not just the fact that he foresaw an America that looked beyond the racial stereotypes of the day to a time when "little black boys and black girls will be able to join hands with little white boys and white girls as sisters and brothers"

It's not just that he was fighting against the gross injustices that stemmed directly from the civil war 102 years earlier.

But the many incidental details I think that are particularly poignant. Whether he says "we refuse to believe that the bank of justice is bankrupt" or "It would be fatal for the nation to overlook the urgency of the moment" he could have been speaking during the economic turmoil of last month and not over 45 years ago.

For MLK it wasn't only about the objectives, but the standard for attaining them "We must forever conduct our struggle on the high plane of dignity and discipline... we must rise to the majestic heights of meeting physical force with soul force". This strategy, followed almost entirely to the letter for 45 years has brought a result that could not have been achieved by any other means.

And the recognition that this is really a struggle for the whole of America: "many of our white brothers, as evidenced by their presence here today, have come to realize that their destiny is tied up with our destiny. They have come to realize that their freedom is inextricably bound to our freedom. We cannot walk alone."

And not just a struggle in terms of skin colour; but the broadest possible sweep of God's intent. As a result MLK immerses his speech in rich Biblical themes: Mercy running like a river; Mountains being laid low* mediated through the magnificent (i.e. secular) Constitution of the United States; which he saw literally as a cheque written for all God's children, to be cashed in through faith in action.

I'm struck most of all by MLKs sense of timescale - which can only be described as pure prophecy. Despite the injustices he was campaigning against, injustices that spanned over 2 centuries he believed that although he might not get there, in fact his own children would: "my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character" From my research all four of his children are still alive (they are in their late 50s or early 60s).

No one should be under the illusion that Obama is any kind of messianic figure. Yet, Obama fits the bill as the man of the moment; being born during the rise of the civil rights movement and elected at just the right time. He certainly appears to be the right man when judged by character and merit; rather than privilege and position. He made it to the highest post in the land in living memory of The Dream at a time of national (international) crisis as a man of intelligence and faith.

Northwest Passage Opens For A Second Time

2008-08-20T16:18:00.002+01:00

According to this Nsidc image, the McClure straits Northwest passage in the Arctic has opened for the second time in two years, the second time since records began. It's worth pointing out that because we are fairly late in the season, there will be more variability in ice-extent, so I wouldn't be surprised if it closed briefly over the next few days. Nevertheless, I would expect it to become open for a significant period of time this year since we have another month of melting to go.

The Cryosphere Today image from 18/08/08 doesn't yet show the McClure strait being completely open - the top and bottom still have some 50%-ish concentrations of ice present. Their calculations are calculated differently and show lower-figures.

As an overall picture then, the Arctic in 2008 is turning out to be fairly similar to 2007, with ice-extent well below the 2005 record and with a few 100 000Km2 still to lose, meaning that the Arctic ice extent could get as low as 4.8mKm2 this year (it's currently on 5.69).

Think Ahead, Think iBase

2008-05-17T10:29:00.009+01:00

This article is promted by the LowEndMac article in Beyond The Mac Mini. About 6 to 7 Years ago I added a page to my (then current) website: The Snial Homepage. I was toying with what Apple might do to produce an ultra-budget iMac based around wireless technologies. The basic idea is that it would be easier for Apple to get existing customers to buy more Macs and distribute them around for specific purposes than for Apple to expand their customer-base. To do this you'd make them really small (so they can be placed anywhere); cut down on absolutely everything and make up for it using the network and just enough USB/FireWire ports. So, the Macs would be capable, but only under the wing of a more powerful computer.

The result was the iBase. Although the performance of the iBase is poor (and was deliberately so even in 2001) Apple seems to be converging slowly on some of its ideas. Consider:

The use of low-end technology in the Mac mini, i.e. relatively slow CPUs.
The missing external drive in the MacBook Air.
The limited number of ports in the MacBook Air (even more limited than the iBase). In particular, like the iBase, the MacBook Air doesn't have Ethernet.
The similar solution for using removable media (e.g. Operating System upgrade) - by using a virtual drive from another computer over wireless.
The small laptop-style keyboard. The one shown in the image is actually a double-prediction. I took an image of a full-sized Black Apple keyboard from 2001; cut off the keypad and cursor pad keys and then inverted it. Apple's keyboards went white in 2002 and the smaller keyboard appeared in 2007 (although it's silver now).
The lack of expandability - even by Apple standards, iBase is restricted by only supporting a single RAM slot (the MacBook Air has its RAM soldered on!).

The iBase makes just as much sense now as it did 7 years ago, or more sense. The move towards cheap UMPCs, such as the popular eeePC says there's a healthy market for small screen computers. The increasing popularity of Linux (in particular, consumer oriented-versions) and Mac OS X means that internet media is more accessible - it's more cross platform. The move towards wireless networks and high-bandwidth internet (Broadband at 512KBit/s had only just come out when iBase was written) means that the traditional roles of DVDs and CDs are falling by the wayside in favour of technologies like Apple TV and the BBC iPlayer. Finally, cheap NAS technology means that computing at all levels is becoming more client-server based; more distributed; more prevalent and yet less obtrusive.

So, the iBase concept is more than just a small computer, it's more human-oriented technology: handy when you want it, but less invasive at the same time.

RIP-11

2008-04-04T23:49:00.003+01:00

It blew up and then it died!

I acquired a PDP-11 over 7 years ago (September 2000). You probably don't want to know what a pdp-11 is, but you should, so here's the low-down:

A pdp-11 is a 37 year old computer, made by a company called DEC that went bust 10 years ago. The exciting thing is that it is so old, big, slow and limited. The processor isn't 1cmx1cm, it's about the size of a Beano annual. There's about 500 chips inside! Only trained personnel ever used these things, because maintenance was such an issue. They cost over £10,000 each when new. They were unreliable.

But, these are the computers that created the internet and the world's most popular programming language called 'C'. These computers gave us email, CAT scans, fractal graphics and early office tools. The bosses of today's computer industry started their careers with these machines. They're epic, but they're unreliable!

Mine was one of the fastest PDP-11s around, a 25 year old model called a Micro PDP-11/73. In today's terms really it's very slow, about 1000 times less powerful than any computer you could buy today. It looked a bit like a tower PC, but it was big, about the size (and weight) of a large old-style radiator. I was going to have a go at trying to use it, but every time I turned it on I could do nothing with it, because the last owner had left a junk operating system on it.

Now that I had a bit of spare time, or rather, because I'm trying to clear away some rubbish, I decided to get the machine going once and for all. I tested out how to use a pdp11 using a pdp-11 emulator on my Mac and it was looking good. And then I checked out all the circuit boards that made up the pdp11, removing them all and then replacing them carefully. The machine is good, it's got 512K of RAM and controls a 30Mb Hard drive.

The clever thing was simply the effort of transferring a new operating system and everything to the pdp-11. I did that by copying it from my Mac to a Zip250 USB drive and then to a PC running Windows98 which I rebooted into DOS so that I could use a program called PUTR which can copy files to ancient 5.25" disks. So, I worked out a way of getting enough of the OS and utilities into 400K (!!!) so I could boot up the pdp11 and then install that OS onto it's Hard Drive.

Easy! But no, it took all day. Just connecting all the cables up from the back of the pdp11 to the front was a nightmare (maybe I got it wrong??!?) and then the VT320 terminal was just generating rubbish for a while. Finally I got it to display something and boot the pdp11 to the floppy disk where my OS was.

AND IT WORKED! For the first time EVER in my life I'd managed to get an ancient minicomputer era computer to run and have control over it!

So, then I copied the OS to it's Hard Disk (and that worked woo!) and spent a few hours copying over the rest of the OS using the same laborious method above. And it was lovely, I turned on the machine for a bit; wrote a bit of a Forth program. I found out it can run about 120000 Forth instructions per second, which means it runs Forth about as fast as a 386 ran QuickBasic.

I turned off the pdp11 and was just about to do a demo and film it and .... as I was trying to get the camera to work. I heard a crackle. And another. Some blue sparks from inside the casing.

YIKE! Oh, good grief!!!!!!!!!! I turned off the computer at the mains - smoke started pouring out the pdp11 while I went to grab a CO2 extinguisher (I have one!). Gee, it smells in the spare room now.

So the pdp11's an RIP-11 now :-( What a disaster!

Ultimate Boeing 747 Challenge

2008-03-20T22:13:00.003Z

In The God Delusion, Richard Dawkins takes Fred Hoyle's Boeing 747 argument and turns it on it's head. The Boeing 747 argument essentially claims it's too improbable that the complexity of living things could have arisen by a sequence of chance events governed by the process of natural selection and therefore it's reasonable to deduce that life has been designed. RD counters that the designer must be more complex than what s/he designs and therefore if living things are too improbable; then the designer of living things must be even more improbable.

As Dawkins says: "A designer God cannot be used to explain organized complexity because any God capable of designing anything would have to be complex enough to demand the same kind of explanation in his own right."

Here is a counter-argument based on the hypothesis is that there's no logical connection between the structural complexity of a designer and the object being designed. We can analyze the hypothesis by considering the design of real systems (I've been involved with a few, maybe you have too).

We know from the concept of structural decomposition, or stepwise refinement (e.g. in software or hardware) that a large design which cannot be comprehended in its entirety by its designer can nevertheless be produced if the designer factors the work into a number of simpler subdesigns; and these in turn can be factored until each particular job is comprehensible.
We know there is, in principle, no upper limit to the complexity of the design that can be attempted in this matter, because we are looking at it from a top-down viewpoint, not bottom-up. In theory this means that given enough time or resources a designer really can design something more complex than him or herself.
We know that there may be an upper limit practical complexity of a design that may be implemented which is governed by the methodology of the design process. In other words, more complex designs don't need a more complex design process, merely a more consistently applied methodology - ie the random factors that affect human beings in a normal environment undermine their ability to create complex designs.

It seems to me on reflection that the human ability to design has little bearing on our physiological complexity; and our limited ability to reason makes us equivalent to a rather 'simple system' far exceeded by the designs we've already accomplished. Nevertheless it's random factors which present the greatest obstacles to our efforts to succeed.

AFAIK, the basic question about whether Evolution is a product of randomness or is determinism seems to have shifted over the past few decades. I distinctly remember in my youth (around 25 years ago) that evolutionists presented evolution as a series of random events subject to the process of natural selection. The important thing to emphasize was the 'randomness' of survival. In retrospect I conclude that this was the case, because it's a good argument against God - if randomness is the source of evolution then obviously it's under no-one's control, not even God's.

However, in the intervening decades we have a better estimation of how badly randomness works as a driver for evolution. And so the argument has shifted to looking at the natural selection side of evolution as a deterministic process. A deterministic process can also be used as an anti-God argument: if a process is deterministic, then there's no decisions for God to make.

This argument isn't really trying to weigh up these two viewpoints. All it's about is saying (a) that the complexity of the designer has no bearing on what is being designed in a situation where a designer is involved. (b) A designer's methodology does have a bearing on what can be designed - a methodology equivalent to a process of natural selection would be extremely counter-productive.

Quakey-Wakey!

2008-02-27T09:37:00.002Z

The biggest earthquake to hit the UK for 25 years struck last night at 0:56 and I was awake to witness it here in Withington, Manchester!

I felt the entire building shaking and saw items moving for several seconds. I kinda had a hunch on what it was after witnessing the Manchester Earthquake swarm of 2002. A couple of my neighbours popped out of their flats and I told them, yeah I'd seen it all before: this was a 3-point-something earthquake and we can all go to sleep.

But I went back and started looking for reports of it on the news. The BBC was ticker-taping about a tremor in the West Midlands, but I quickly found a Wikipedia article about it being written as I was refreshing the page. It first said it was a Manchester earthquake with unknown magnitude, but as the list of reports came in it quickly settled on being a 4.7 to 5.0 earthquake in England. Turns out it was a 5.3 in Lincolnshire. It's even reported on CNN (they found an American chap living in a timber-frame Tudor house to interview, of course!)

Arctic Valentine

2008-02-24T17:11:00.005Z

The Arctic has given us a Warm-hearted Valentine's gift!

This is going to be a short post - I keep watching Cryosphere today in order to monitor current sea ice extent. Summer's sea-ice extent loss was so dramatic I posted a couple of items, the second one being one where I predicted the amount of sea-ice for the coming winter.

Actually it looks like the majority of the winter has been better than I expected. That is, the winter was almost a record low for maximum extent wheras I expected it to be lower. In fact, for about a week, during a cold spell at the beginning of February the ice-extent was greater than a year ago by about 50k to 100k Km2.

The surprise comes in the middle of February. The Extent appears to have dropped by a stunning 700,000 Km2 in one day! When I saw it yesterday I thought it was a data error, but the extent has followed on from there instead of returning to it's previous point. So anyway, I've included an enlarged picture. It's one taken from the site, but I've enlarged it 2x and chopped out the rest of the graph. It may be that it's an error, but to give you an indication of how massive this is, it's about 5x greater than the worst single-day drop around this time last year and about 25% greater than the worst single-day drop in the record-breaking summer 2007. It means that the ice-extent (in mid-Feb) is currently at the same position as it was last April! It could go above 13M Km2, again, but given the current weather conditions near the end of February (it's quite a bit warmer than I'd expect); I'd be surprised!

God Delusion#2

2008-02-22T16:40:00.006Z

OK, so I've watched a bit more of Life on Mars and it's really great!

This is the second part of my God Delusion review. Here I cover chapters 3 and 4, which are based on arguments for God's existence and RD's argument against. I'm a bit more sympathetic in these chapters since he's less inclined to deride Christians as thickos and I like some of what RD writes when he's writing directly about Science. I'll do it as numbered points as before.

Infinite regress (p101). In a sense this is RD's weakest point. The physical world really does have a problem of infinite regress because we can observe causality, we always have to posit a physical mechanism which leads us to the current situation Ut <= Pu(U(t-∂)). We can't avoid the problem of regress because we always need a function Pu to provide the 'explanation' for the universe as we see it now. Since Pu is autonomous and not self-aware, it itself is a mechanism which requires explanation: Pu <= Mv(Pu-ß). Ultimately, the problem lies with science itself, because the problem is a result of seeing things in terms of transformations and science is a means of representing transformations, i.e. it is Px, My etc. This means that the only way out of the regress (i.e. the only way to make sense of being able to see the world scientifically, i.e. as transformations) is to assume that there is something, let's call this Ω which is capable of producing Px, My etc, but can't be represented, i.e. exists outside of science. Because Ω cannot be represented scientifically, Ω cannot be a mechanism (because a mechanism is equivalent to a transformation).
Dawkins makes a trivial error with his analysis of omnipotence and omniscience. That is, Being all-powerful doesn't mean he's changing history or the future, it just means he's in control. The two terms are just ways of expressing the ideas that we can be confident he hasn't missed anything and that ultimately things will go according to what he wants.
I don't really care about ontological arguments, they're not biblical and don't make sense - Dawkins is right here IMO. And the stuff about argument from beauty and experience I think are circular - that is, beauty and experience are both evidences of God if you already believe in him, but if you don't it's easily explained. That is, I have God experiences, but I don't really think they're useful to anyone but me.
I looked into his Argument from Scripture - in fact, the Gospels clearly demonstrate that Jesus thought he was God, but being selective with Scripture could lead you to think otherwise. Similarly, RD trots out the Chinese Whispers argument against scriptural accuracy (see post #3); his argument about Jesus' birth really isn't supported by scripture; his treatment of Jesus' geneology, New Testament Canon are really rather superficial. His argument from religious scientists I think doesn't demonstrate anything: emminent scientist Christians are a minority, but they do exist and this means they must be right or wrong or probably wrong or what?
Finally, RD introduces the Baysian argument using a Christian writer (I presume). However, I've never heard of him, but RD's critique of it seems largely reasonable to me, but personally that's because I don't think it makes sense to assign a probability to God's existence. Anyway, I think he uses that section, mostly because it leads him nicely into chapter 4.
Complexity. RD says: "By invoking a designer, the designer himself has got to be at least as improbable. God is the ultimate Boeing 747." In a sense RD is saying this because he's assuming God is a system made of parts, based I guess on the reasoning that we design things and we're made of parts. But this argument itself is fallacious, because it assumes our consciousness and reasoning; our will and ability to design is only due to our physical makeup. Which is only true if you're already a materialist. Furthermore, it assumes that there's a relationship between our own complexity and the complexity of things we are able to design when actually the two things are independent. See the blog Ultimate Boeing 747 Challenge.
Much of chapter 4 is interesting. I really liked reading about his arguments on irreducible complexity. RD rightly critiques 'God of the Gaps' theology, but he gets the theology wrong - in reality God is God of everything, i.e. what we understand and what we don't. He's God over it all. The stuff on the flagella bacterium motor is really good and interesting. His criticism of Michael Behe, the ID proponent, is scathing in the extreme as RD bathes him in a torrent of negative adjectives in every phrase where he appears (well, maybe not that bad, but it is noticable :-) !)
RD isn't a physicist (but neither am I :-D ) and he's weaker when talking about the Anthropic principle and cosmology. He guesses at the probability of life appearing on a planet that's made of just the right stuff in exactly the right orbit around a star (it's part of the Drake Equation). His conservative guess is 1/1billion, but he's not following the Drake equation carefully and totally fails to mention the Fermi paradox: i.e if life is at all common in this galaxy, it'd only take 5 to 50 million years to explore it - so why don't we see evidence of ET everywhere?
Nevertheless even talking about the weak anthropic principle he still heads off into pure speculation by extrapolating from the 'billions of planets' that have bacterial life to the supposedly rare occurance of intelligent life. Yet we simply don't know the probabilities of any of this - i.e. the probability of amino acids becoming some kind of primitive dna/rna nor the conditions of the early earth to within even a vague order of magnitude.
"You are so 19th Century." Dawkins wonders why he was criticized by theologians in this way. He figures it's because the 19th century was the last time someone could genuinely believe in miracles. I think he should really have asked them why they say that. Here's an alternative theory: what they mean is that Dawkins is Modernist, not Post-modernist. The difference being that Modernism assumes truth is objective, wheras Post-Modernism doesn't and it's thinking first appeared in Hegel's philosophy in the 19th century. RD is firmly in the first camp. Moreover, much of what passes for modern Atheism is really a belief-system stuck in the late 18th and early 19th centuries. Some casual examples: (a) Atheists use the word religion in singular, particularly when they're referring to Christianity, except when they're referring to Catholicism. This only makes sense when you think back to the 18th century when Christianity was the only European religion going, but Protestants would frequently refer to Catholics as having a separate religion. (b) Atheists frequently state that religion is the cause of all wars. Well, that was fairly credible in the 18th century when Europe was still reeling from the effects of the religious wars in the 16th and 17th centuries, but it's largely a nonsense in the 20th and 21st centuries. (c) RD frequently talks about 'Consciousness raising', but this is really just a euphemism for 'Enlightenment', the 18th century's Atheist movement.

In the end then, chapters 3 and 4 are probably the nicest in the entire book, I just don't think they make a good case against God's existence. So, hey-ho, let's move on to the next chapters.

God Delusion#1

2008-02-19T00:16:00.006Z

It's kinda inevitable that if I started to read the God Delusion by Richard Dawkins I'll end up making comments about it, so here goes. I'm basing my comments on the paperback version which includes some additional material.

I was thinking of writing a fairly pedantic response, but there's just so much there I disagree with I'll have to be far more judicious. In this post I'm confining my critique to where I believe RD is factually wrong or where he reveals nastier sides to his character. At the moment I'm only 81 pages into his incessant diatribe so there's plenty of space for me to reasses the quality of the book. However, here goes:

Carl Sagan's Pale Blue Dot quote. Here, Sagan claims Christians argue "no, no, my god is a little god and I want him to stay that way." When in fact Christians argue on the basis of the wonder of the universe that he's exactly the opposite and that the more amazing we find the universe is, the more amazing God must be. Dawkins reiterated this quote in a TED lecture. I don't know why - Christians don't preach it, and we don't believe it.
Pages 46-48: The Danish Cartoons of Mohammed(pbuh) riots. The thing that gets me here is Richard Dawkins gets it so wrong. He says the episode 'illuminates society's exaggerated respect for religion' in fact the original thing was triggered by a bunch of secular cartoons that displayed a complete disrepect towards Muslims. RD passionately defends the right of secularists to ridicule religion, but it wasn't Atheists who died from the riots, but Christians and Richard Dawkins cares nothing for them, his adjectives are 'ludicrous', 'comic', 'tragedy' for the whole episode.
As you read through Dawkin's book you find that he pillories Christians at every turn whilst portraying Atheists in consistantly glowing terms. In fact he believes mockery is the best way to deal with Christians. As RD says (p55) "Thomas Jefferson as so often, got it right when he said 'Ridicule is the only weapon which can be used against unintelligable propositions.'
Secularism and the Founding Fathers (p60-68). Here the whole section is highly disengenious. RD starts with a false premise "It is conventional to assume the founding fathers... were deists." Is it? I'd always been lead to believe they were a mixture of fairly radical Christians of the Pilgrim Fathers kind and Enlightenment thinkers (including Deists). I found a webpage which lists the actual religious affiliations of the 56 signees and it turns out that even though the majority were Christians, RD quotes only from the 4 Deist/Unitarians.
RD supposes that the reason Christianity is weak in the UK is because the UK was weary of religious wars or because it's full of ineffectual vicars (p62). He's half-right there. Actually it's easy to see why Christianity is weak in the UK, because church attendence tailed off massively after WWII, a secular war. Though it's probably true there's lots of UK vicars who see their role as having "innoculated vast swathes of the English against Christianity."
Burden of proof. Strangely, RD believes on the one hand that the burden of proof rests on Christians (p74-75) and yet that it's unnecessary to read what they write (p14-p15). Admittedly, he says he'll read from credible Christians (p14), but most of the quotes he uses are from Christians I've never heard of, apart from Alistair McGrath p78pp1.
Evolution as an Atheist weapon (p92). in the end RD sees the point of talking about Evolution as part of a war against Christianity "the real war is between rationalism and superstition... religion is the most common form of superstition." This is why RD isn't interested in avoiding conflict between Science and Christianity and why he's so critical of Atheists and Christians who do.

At this point I'm leaving it for now, because I'm only up to Chapter 4 and I want to watch the next episode of Life On Mars on DVD :-)

-cheers from julz @P

Super Green Hero!

2007-12-29T15:11:00.000Z

I've been meaning to write this post for a little while now, just wanted to say something about James Alden's heroic tackling of an armed robber at Somerfield on Wednesday Dec 19.

Apparantly the chap had raided a number of locations in Withington and Didsbury and struck again at the Somerfield store in West Didsbury; poking a gun in James' back while grabbing cash from the till.

James waited for the guy to get distracted and then spun round; tackling him - though he quickly escaped and as far as I know hasn't yet been caught. And the gun was a non-functioning replica as far as we know.

I guess the key thing is that the way I look at it, it should be normal practice for people to respond to situations like that, as did the passengers of United Airlines Flight 93 and part of the reason we don't is because our secular culture causes us to act as individuals: we see that a small minority of people are putting us in danger and that acting together they would be overcome, but the fact that 'I' am in danger means we don't act.

So why did James respond? My guess is that it's two things: firstly his eco-activism means he's used to doing what others don't have the guts to do - stand up to those in power when what they're doing isn't right. Secondly, his Christian faith gives him a different perspective on life, one where risking your life is sometimes reasonable, and which affects his psychology at a deep level.

As James said when he met us up at the pub a day later: "I almost met my maker yesterday" before casually starting on his pint.

DemonicVD Camcorder

2007-11-29T16:11:00.000Z

I've done a Video project using a DVD Camcorder. It was a nightmare. Read on.

I videoed a showcase production for a friend last Saturday using a Sony DVD91E Camcorder.

Aside from the low quality - which was even worse than normal because I had to use LP mode - you have to bear in mind that the disks will act as gyroscopes when you move the camera - they will be extremely sensitive to camera shake and twist. So, I finished the filming and took the disk home. It was an 8cm disk so it doesn't fit in any slot-loading Mac - I had to use an old iBook. But it thought the disk was blank!

Turns out the DVD needs 'finalising'. so then I asked a teacher friend from Ivy Cottage who's school had a DVD camcorder which I picked up on Wednesday. I finalized the DVD (which meant I ended up holding the cam perfectly steady in my hands for 3mins, because it put up a dialog box saying "Finalizing: Do not subject the camera to ANY vibrations." but only after I selected the option (Grrr!!)) Then the disk was too dirty to read properly on the mac, so it took a bit of cleaning. I finally copied the files from the disk, but of course, I can't import them into iMovie, because it's DVD .VOB files not QT movie, .avi or .dv files. It took lots of faffing about until around 11:30pm until I got FFMpegx to convert the file to .dv format (import to iMac, create disk image, create DVD, fix DVD image and recreate etc, download FFMpegx and libraries...).

Awful. In 7 years I never had any problem like that with a tape-based system. Just plug it in, import video. Off I go.

OLPC Alternative 2

2007-10-15T10:11:00.001+01:00

Well, hot on the heels of the eeePC is the DecTop.

The specs are a bit lower (366MHz Geode, 128Mb RAM, 10Gb HD, No Ethernet), but DEC will sell you a pack of 4 for $75 each (including keyboard and mouse). This takes the cost of our theoretical platform to around £45 + £85 = £130! ( or £520 for 4).

However, (and this is a big however), the DecTop isn't new. Actually it's an old AMD concept called the PIC, designed for developing countries, which doesn't seem to have been successful in the marketplace. The prices Data Evolution Corporation are offering are in fact sales prices, which kinda implies they'll stop selling them soon!

OLPC Alternatives

2007-10-13T13:11:00.000+01:00

I'm always on the lookout for OLPC alternatives for Africa. It's actually rather tricky, for the following reasons:

You really need a low-powered device, something that can be powered by hand or via solar cells. This is because often in Africa the electricity isn't often reliable. Realistically a person could provide up to 466 Watts, so 15 minutes worth of effort can power a 50 Watt computer/display for up to 2.33 hours.
You need a system which can survive extreme conditions. That's another reason why it needs to be low-powered, because low-power means cool.
You need a system which uses pretty much off-the-shelf components: standard RAM, pretty much standard HDs.
You need a system which is low maintenance. This pretty much rules out sending old second-hand PCs. There's 2 reasons for this: replacement parts are hard to find and computing expertise is hard to find.
You need a system which has conventional interfaces: VGA, USB.
You need a system which is very cheap. The $100 laptop is currently at roughly $200 which is realistic to donate in 10s of units (£1000).
You need a system which is based on open source software, e.g Linux.

Not many computers fulfill these kind of criteria. One of them is the Asus eeePC.
Research machines are currently selling them for £169 each for the 2Gb version. However, they are for educational use only.

Another alternative is the FitPC.
Assuming we have to pay the full whack of $285 (£150) this means we can put together a cheap developing country PC for around £260 (£85 lcd display, £150 machine, £10 keyboard/ mouse, £20 Hand crank PSU).

However we can probably cut this down somewhat. If we sell it through a charity on a non-profit basis we can probably do it for half the price: $143 (£72) and then get the rest of it ex-vat, we get: £72+£98 = £170 for the machines themselves (we'd then have to transport them).

2007-10-12T20:42:00.001+01:00

People can do nice things, and just because you ask them!

2007-10-10T15:25:00.000+01:00

Imperial measurements - what Americans call English measurements - really wind me up. I was born in the UK in the late 1960s and spent my childhood learning metric only to find that decades later most Brits (even ones much younger than me) still use imperial measurements for most normal things and still reuse the same arguments for their continued use.

And it's hard for me to switch over too. I've become used to thinking about liquids in litres (rather than pints or gallons), because petrol is bought in litres and UHT milk cartons / wine / water / fruit juice is too. Temperature is normally metric in the UK (so that's easy). And for a long time I've thought about short distances in metric and it's only in the past decade I've started to metricize the rest of my life.

And I mean, just normal things: I'm 1.7m tall and weigh 68Kg. My church (and my old place of work) is about 2Km away. Nottingham, where my parents live is just over 100km.

The real difficulty has been reading stuff in imperial on the web. Most of the world is metric, but most of the web is US-centric which means a lot of measurements are imperial even when they're technical. I kept finding this on Space.com: it's really wierd reading articles aimed at an international audience; about the latest space developments and seeing it all measured in pounds and feet, miles, farenheit and gallons. It's like - Nasa has been taken over by Torchwood!

So a few months ago I emailed one of the guys there and he wrote back to say:

“This is something you need to take up with the style of the major U.S.
syndicator of news: The Associated Press. We follow their style to be
consistent, and they dictate using only Fahrenheit.”

Yet just this week I noticed they'd changed to including metric measurements! Dave Mosher says they've updated their style guidelines, but it just goes to show that people can change their minds and be really considerate :-) !

Big Stick Sociology

2007-10-05T16:31:00.000+01:00

Yesterday I got threatened by someone with a big stick about the size and shape of a baseball bat. It's OK, I wasn't attacked, I'm just surprised it's possible to get away with that kind of behaviour in public.

I was cycling home from Stockport*
View Larger Map and as I got to the crossroads at Parrswood road / Fog lane a guy in a parked car opened his door right in front of me. So I shouted "Watch it!" and he swore at me to shut up. So I yelled "You don't have the right to tell me to shut up!" and he grabbed something like a baseball bat from his boot* and started to threaten me with stuff like "Come over here and I'll smash your F***ing face in!"

I declined. I was several metres ahead of him; toying with the idea of jumping the lights (which were still red), but I still held my ground and eventually him and his verbal obscenities went into the nearest house (presumably to show off his fine lump of wood).

So that's it really. I reported the incident to a Community Support* police officer. The thing I'm thinking is that hey, there were lots of witnesses, but would they have got out of their cars to help? I think ultimately most of us are too scared to risk ourselves in the face of intimidation and that's why it works. But really it should work the other way round, there's more of us than there is of them!

[* Stockport is in the UK. The Boot of a car is the 'Trunk'. Community support officers are volunteer police]

OLPC Deal: Give Two Get None

2007-10-04T13:10:00.000+01:00

I really love the OLPC.

Well, I love everything about it apart from two things, they use an AMD x86-based CPU when they could have used a lower-powered ARM-based machine (e.g. an Arm11 or Cortex A8). And the OLPC "Give One Get One" deal only applies to the US and Canada.

For the rest of the world, the deal is: "Give Two Get None" since outside the US you can donate to give away XO laptops, but you'll never receive one.

But that's OK, I'll buy into that, sign me up Nick for donating 2 XO laptops - in fact I'll sign up for 4. At $800 it's still a great deal!

I'd like to donate in order to seed the XO in particular places: Zambia (where Dignity online operates) and in Senegal (where a cameroonian friend of mine has an interest).

But it's not the only way of doing things, stay tuned for a future post!

Mac mini madness!

2007-10-01T10:25:00.000+01:00

Well, there you go. Today Apple UK are offering a special deal on a refurbished Mac mini: A 1.83GHz Core Duo Superdrive for only £499.

Except that... A brand-new Mac mini 2.0GHz Core 2 Duo with a 50% bigger Hard Drive in a nice box costs the same. Something tells me the 'special deal' isn't going to sell!

Pity, 'cos I'm very much a Mac mini fan. In the UK it's still the best Mac deal you can get: with it you can buy a complete Mac for around £500 (e.g. £399 Mac mini + 17" LCD monitor from Microdirect (£85) + Apple Keyboard (£29) + Trust Optical Mouse (£4.50)) => £517). The next best thing is a Superdrive Mac mini at £617 followed by a Combo Macbook at £699.

Even so, I think Apple should sell a... what I would call a Mac nano - a 11" wide-screen LCD (1024x600) backed onto a slow CPU with 512Mb RAM Mac with only Airport/BT networking and two USB ports. With this machine there's no Combo / Superdrive, no external video and just one RAM slot (occupied by the 512Mb). Then I'd sell it for around £350 (£399 with wireless Kbd/Mouse deal). The point would be some kind of satellite Mac good for internet stuff etc. Or is that what the rumoured Apple PDA is going to be? Or would such a machine be usurped by the (other) rumoured Macbook mini/nano?

OK, so my Mac nano might be madness, but at least it's not as mad as a special deal that's anything but!

Gunning for ARM

2007-09-26T09:41:00.000+01:00

I'm a fan of ARM Processors - it's the most successful CPU on the planet today, by a factor of 3 or more. ARM processors go inside pretty much every mobile phone these days (it's possible, though unlikely, that some low-end phones don't have one); hundreds of millions of gadgets have them (from handheld games consoles to Network servers); they're so ubiquitous that it's worth using them for ultra-low-end microcontrollers[1][2] and it's popping an ARM processor in pretty much any device: the Marvell WLAN used inside the OLPC uses one for example.

ARM CPUs are successful, because they are actually a good design: Lean and Clean; they do more with transistors than x86 ever can; spanning a range of CPUs from <100k transistors and up to several hundred MHz with the Arm11.

So, I was really surprised to find OLPC failing to use and surprised further that Intel sold off it's ARM-based XScale CPU range last year. But now it's becoming clear, Intel are now anti-ARM and want to push their inherently inefficient x86 CPUs to ultramobiles and even PDAs.

With Moorestown Intel want to use x86 where ARM would make more sense. But probably the most annoying thing is their justification for it: "Second, if you want to get a great experience surfing the Internet, you need an IA-32 Intel architecture, because the Internet is written around it" This is just complete absolutely untrue FUD - the internet is written around being CPU independent - and that's how it should be.

People are gunning for ARM, we need to be more active when advocating it.

Performa 400 Paradise!

2007-09-21T01:04:00.000+01:00

After I started re-using my 14 year-old Macintosh Performa 400, I just can't help raving about it! If you've never heard of one, then it's worth taking a step back in time to 1993 for a recap.

I started using Macs in 1986, 512K monochrome machines, but I couldn't afford to buy one until a year into my first proper job, in 1993. The best Mac I could sensibly get hold of was a Performa 400 - a 16MHz 68LC030 Mac with 4Mb Ram and a 40Mb HD, running System 7.1. It cost me about £1280 with a printer. Although slow even by those days it was fantastically versatile, I produce decently edited brochures; bought Think C and wrote some Mac Programs; I upgraded the memory to 8Mb; the Hard disk to 270Mb and I added a SCSI Zip drive and CD Rom. This was the machine that got me onto the internet in late 1995, early 1996 with Netscape 1.18 and Eudora 2.x for email.

Since then I've gone through a number of Macs: A PowerMac 4400, a PowerBook 5300, a tangerine iBook, a 600MHz iceBook and now my two main Macs are the 12" PowerBook G4 I'm typing this on and an iMac G5.

But I still love the P400, which I reacquired from my sister when they upgraded. It's great! For a start... it still WORKS! And with it's ethernet PDS card I can use an old web browser and also ftp. The neatest thing though is still Think C - it's about 17 years old, but as a programming environment, still much more productive than XCode. It's 1Mb of pure genius; efficient and highly usable for (really) basic stuff! And to think it's all being done on a 16MHz 68030, a cpu roughly 1000times slower than today's computers (over 200x slower than my G4), a cpu so primitive they wouldn't even put it in today's crummiest mobile phone!

It's like a trip to computing paradise - they don't make computers like that anymore :-)

Mysterious Mobile Phone Episode#1

2007-09-14T20:46:00.000+01:00

Just a short post this. There's the feeling that the UK is sleepwalking into a Police state. Usually I take all this with a pinch of salt - or rather a hefty bag of the stuff, but now I'm not quite so sure!

A friend of mine was at the recent protests at Heathrow. Lots of fun I hear, no real bust ups between the protesters and police, just everyone playing their part. During the course of this my friend had a number of stop-and-searches, for things like, cycling. The normal thing is to not give name and address unless they have a particular reason. But on one occasion they took the IMEI number from his cheapo Nokia 1112 phone. Pretty wierd that, they had a laptop somehow connected to to the phone network or something when they were doing it. We thought it was probably just to keep track on him.

But this week, his phone has been mysteriously security locked (which they only do if it has been reported stolen, which it hasn't been). So he's now phone-less! Anyone know why the phone has been locked?

Arctic Sea Ice Extent

2007-09-13T17:34:00.000+01:00

I’ve finally gotten around to creating a blog, so I need to start it off somehow with a post, hopefully not a completely purile one. Since I obsess a bit about global warming and climate change I’ll start with a thrilling post about the Arctic sea ice extent.

If you didn’t know, the Arctic sea ice extent has already broken the previous record of 5.32M Km2 set in 2005 by 1.08M Km2 - it’s now 4.24M Km2 and could easily fall for another 2 or 3 weeks (although it may stop any day now). It’s not just that it’s smaller than ever, but that it’s breaking records of all kinds:

It’s the largest single fall recorded for a single year.
Highest temperatures Recorded.
It’s the first time the Northwest Passage has opened.
It’s melted perennial sea ice the size of California (Ice that’s been around every day of every year since at least 1979).
Ocean warming itself is now contributing to ice melt.

The thing for me though is that most people are still predicting the Arctic ice caps will be free of ice in the summer by 2030, but simply looking at their graph makes it look like (at the current rate over 2005-2007) the ice caps will be free of ice by the summer of 2015. The calculation’s simple: 4.24M Km2 / 0.55M Km2/Yr => 8 years.

But how bogus is my guess? Well, I’m not a climate scientist, so probably very! But it’s worth noting that my estimate is based on a current rate of decline when it’s fairly obvious that the rate of decline is accelerating. Secondly, not only is the rate increasing, but it’s becoming more consistent. Year to year increases since 2001 haven’t exceeded 0.45M Km2 (average 0.26M Km2), which prior to 2001 averaged 0.68M Km2. Thirdly, there's a good reason to believe ice melt will increase and be more consistent - namely that the arctic ocean is playing a greater rôle, absorbing more summer heat, because the cap is shrinking. And the ocean will act as a massive heat exchange, preventing the cap from fully recovering in the winter, and by regulating heat release during the yar.

Scary isn’t it?