This is the 2010 archive, for 2011 see 2011 Plan 28 Media Coverage
I'll be keeping this page updated as new stories are posted. Articles with * next to them are the most in-depth.
October 3, 2010
The Independent: One of the great inventions that never was – until now? *
The Independent: Start the Engine
October 4, 2010
The Daily Mail: Campaign to build Charles Babbage's steam-powered 'Analytical Engine' - 173 years after he designed it
O'Reilly Radar: The 100-year leap *
October 5, 2010
The Register: Legendary steampunk computer 'should be built' - programmer
THINQ.co.uk: Geek plans to build Babbage compute
October 6, 2010
iProgrammer: Plans to build Babbage's Analytical Engine
October 7, 2010
Fudzilla: Babbage's analytical engine should be constructed
October 8, 2010
e-Katalog: Британский энтузиаст намерен построить паровой компьютер
October 9, 2010
Der Standard: Dampf-Computer von 1837 soll Realität werden
October 11, 2010
elektor: Dampf-Computer soll Realität werden
Der Standard: 1837 entworfener Dampf-Computer wird gebaut
October 12, 2010
sg.hu: Megépülhet az 1837-ben megálmodott gőzzel működő számítógép
October 14, 2010
BBC News: Campaign builds to construct Babbage Analytical Engine *
redOrbit: Campaign To Raise Funds For Analytical Engine Underway
The Daily Telegraph: Campaign launched to build Charles Babbage's Analytical Engine
UPI: Historic computer replica proposed
ubergizmo: Charles Babbage's Analytical Engine could very well be realized
Komputer Swiat: Chcą zbudować komputer na parę
October 15, 2010
Tech.Blorge: Babbage’s Analytical Engine may get built
TG Daily: Campaign launched to build Babbage's steam-powered computer
Geekosystem: World of Steampunk Rejoice: Somebody Might Build Charles Babbage’s Analytical Engine
PC World: Rebuilding a 19th-Century Computer: One Programmer's Quest
Inhabitat: UK Campaign Aims to Build Legendary Steam-Powered Computer
Gizmodo: Charles Babbage’s Failed Computer From 1837 Will Be Built
Discover Magazine: Get Your Steampunk On: This Guy’s Building a Computer From 1837
Geeks are Sexy: 1837 steam powered computer could finally enter production
io9: Bringing back Babbage
sudkurier: Computer unter Dampf
microsiervos: Proyecto para construir una máquina analítica de Babbage en el MundoReal™
October 17, 2010
Escapist Magazine: Campaign Pledges to Finish 19th Century Steampunk Computer
October 18, 2010
PCR: Plan to build Babbage steam computer
Gizmag: Ambitious project to bring world's first general purpose computer to life
ITProPortal: Babbage Steam Computer To Be Built
Hexus: Babbage behemoth battle
TechNewsWorld: Geek Seeks to Bring Babbage's Analytical Engine to Life
PC Pro: Wanted: Assembly programmers for 173-year-old computer *
Techwatch: 170-year-old steam powered computer to be built?
PhysOrg.com: Campaign to build 1837 Babbage's Analytical Engine
GreenMuze: Building Babbage's Analytical Engine
Hirado: Meg akarják építeni Charles Babbage analitikus gépét
hvg: Meg akarják építeni Charles Babbage gőzhajtású számítógépét
October 19, 2010
CBS News: Move to Bring Babbage's Famous Computer to Life
detikinet: Kampanye 'Plan 28', Ajak Orang Ciptakan Prototipe Komputer Jadul
Heise: Spendensammlung für Dampfmaschinen-Computer
October 21, 2010
De Standaard: En als we eens de stoomcomputer van Babbage bouwden?! *
NyTeknik: Nu ska ångdatorn äntligen byggas
October 22, 2010
As it happens (CBC Radio): Prithee, dispatch thine riotous video portraying the farcical antics of cats!
October 25, 2010
Radio New Zealand: Long interview about Plan 28 *
October 26, 2010
Wall Street Journal Europe: The Ultimate Steampunk Project *
TechEye: Steampunk computer to be made of brass and powered by steam
November 2, 2010
Haaretz: אחרי 170 שנה, המחשב הראשון קורם עור וגידים
Wall Street Journal Europe: Geek immortality from €10
November 4, 2010
PÚBLICO: O século XIX dos computadores a vapor está a nascer agora
November 12, 2010
Irish Times: Revisited invention planned as tribute to 'father' of computing *
Wednesday, October 20, 2010
Monday, October 18, 2010
A Plan 28 completion date
Today in 1871 Charles Babbage died. 11 years from now it will be 150 years from Babbage's death.
He kept working on the Analytical Engine up until his death. Let's make sure that his Analytical Engine is built by October 18, 2021.
Help get the word out about Plan 28.
He kept working on the Analytical Engine up until his death. Let's make sure that his Analytical Engine is built by October 18, 2021.
Help get the word out about Plan 28.
Sunday, October 17, 2010
Plan 28: the first 10 days
So, it's been 10 days since I posted the Analytical Engine PledgeBank and the total number of signatories stands at over 2,700 with many people pledging £50, €100 or even $1,000. The PledgeBank estimator reckons I'll hit 42,435 pledges (84.9% of target) by the target date. Given how much more than $10/£10/€10 many people are pledging I'd imagine that my goal isn't unrealistic, but please keep spreading the news.
As well as pledges of money I've received pledges of professional design and manufacturing help, document digitizing, CAD software and more. These are super-helpful.
In addition there's been a lot of media interest. The best articles are the BBC's Campaign builds to construct Babbage Analytical Engine and The Independent's One of the great inventions that never was – until now?. If podcasts are your sort of thing then you can listen to the excellent session about Plan 28 on TWiT #269.
There's also been some nice tweet-support from BBC broadcaster Maggie Philbin and author William Gibson.
And behind the scenes I've received hundreds of emails of support or with questions. To help field some of the questions I did a reddit AMA and posted a FAQ.
Also behind the scenes there's a proper design well underway for the Plan 28 web site which will transform it from my awful design skills to something respectable.
And, finally, I'll be meeting with the folks at the Science Museum early in November to talk more about Plan 28.
Above all: thanks to everyone who's written about Plan 28 in the media, on Twitter or on a blog, thanks for all the pledges of money or services, and all your kinds emails.
PS Forgot to add that descendants of Charles Babbage have been in contact to express their support for the project.
As well as pledges of money I've received pledges of professional design and manufacturing help, document digitizing, CAD software and more. These are super-helpful.
In addition there's been a lot of media interest. The best articles are the BBC's Campaign builds to construct Babbage Analytical Engine and The Independent's One of the great inventions that never was – until now?. If podcasts are your sort of thing then you can listen to the excellent session about Plan 28 on TWiT #269.
There's also been some nice tweet-support from BBC broadcaster Maggie Philbin and author William Gibson.
And behind the scenes I've received hundreds of emails of support or with questions. To help field some of the questions I did a reddit AMA and posted a FAQ.
Also behind the scenes there's a proper design well underway for the Plan 28 web site which will transform it from my awful design skills to something respectable.
And, finally, I'll be meeting with the folks at the Science Museum early in November to talk more about Plan 28.
Above all: thanks to everyone who's written about Plan 28 in the media, on Twitter or on a blog, thanks for all the pledges of money or services, and all your kinds emails.
PS Forgot to add that descendants of Charles Babbage have been in contact to express their support for the project.
Thursday, October 14, 2010
What Nature didn't say
Nature has a nice article about scientific software which starts by mentioning the hacking of the Climatic Research Unit and the release of software from the hacked files, and then goes on to talk generally about the state of scientific software. My summary would be that it's generally a mess because software engineering has crept up on scientists and now they need to get educated about things that have been common in the commercial software world for years.
Which is pretty much what I said on Newsnight in December 2009.
The article begins:
True enough that the messy code from CRU wasn't shown to compromise any of their scientific results. None of the enquiries into "ClimateGate" examined the CRU code. I did show, however, that the code I saw was buggy. (See, Whoops, there's a third bug in that code and Bugs in the software flash the message 'Something's out there'.) In fact, the best that can be said is that CRU's code was buggy and we don't know if those bugs have a material impact on the science.
And another piece of CRU-related code, the code used by the Met Office to produce the CRUTEM3 temperature set was similarly buggy. I first showed that there were errors in the way the station files were generated (see The full response from the Met Office. By the way, I'm still waiting for them to make good on their promise to credit me) and then (with Ilya Goz) showed that the program used to generate the station errors in CRUTEM3 wasn't working (see Something odd in CRUTEM3 station errors and Met Office confirms that CRUTEM3 station errors are incorrectly calculated.)
What's interesting about these bugs is that practices like unit testing or automation (through even make, which has been around since the 1970s) would have helped avoid the problems the Met Office saw. And likely the bugs in the CRU code. It really would be a good idea for commercial best practices to be introduced to scientists.
Nature didn't mention any of that. Pity. Those are real bugs in the real software related to CRU.
I don't know if any of this leads to problems with actual climate science, that would take a real examination of the source code used to produce published papers. But it does concern me that it was so easy to find so many errors. There really could be a nasty surprise lurking in the code.
Which is pretty much what I said on Newsnight in December 2009.
The article begins:
When hackers leaked thousands of e-mails from the Climatic Research Unit (CRU) at the University of East Anglia in Norwich, UK, last year, global-warming sceptics pored over the documents for signs that researchers had manipulated data. No such evidence emerged, but the e-mails did reveal another problem — one described by a CRU employee named "Harry", who often wrote of his wrestling matches with wonky computer software.
"Yup, my awful programming strikes again," Harry lamented in one of his notes, as he attempted to correct a code analysing weather-station data from Mexico.
Although Harry's frustrations did not ultimately compromise CRU's work, his difficulties will strike a chord with scientists in a wide range of disciplines who do a large amount of coding.
True enough that the messy code from CRU wasn't shown to compromise any of their scientific results. None of the enquiries into "ClimateGate" examined the CRU code. I did show, however, that the code I saw was buggy. (See, Whoops, there's a third bug in that code and Bugs in the software flash the message 'Something's out there'.) In fact, the best that can be said is that CRU's code was buggy and we don't know if those bugs have a material impact on the science.
And another piece of CRU-related code, the code used by the Met Office to produce the CRUTEM3 temperature set was similarly buggy. I first showed that there were errors in the way the station files were generated (see The full response from the Met Office. By the way, I'm still waiting for them to make good on their promise to credit me) and then (with Ilya Goz) showed that the program used to generate the station errors in CRUTEM3 wasn't working (see Something odd in CRUTEM3 station errors and Met Office confirms that CRUTEM3 station errors are incorrectly calculated.)
What's interesting about these bugs is that practices like unit testing or automation (through even make, which has been around since the 1970s) would have helped avoid the problems the Met Office saw. And likely the bugs in the CRU code. It really would be a good idea for commercial best practices to be introduced to scientists.
Nature didn't mention any of that. Pity. Those are real bugs in the real software related to CRU.
I don't know if any of this leads to problems with actual climate science, that would take a real examination of the source code used to produce published papers. But it does concern me that it was so easy to find so many errors. There really could be a nasty surprise lurking in the code.
Wednesday, October 13, 2010
Plan 28 (Analytical Engine) FAQ
Answers to your questions about the Babbage PledgeBank:
1. Can I pledge more than $10/£10/€10?
Yes, of course! Many people have done so. The system doesn't have a box where you can enter an amount, but you can contact me and let me know, or, even better, publish a public comment with your pledge amount.
2. Can I pay you the money?
Not yet. Currently, I'm working on building up enough pledges to make sure this is viable. Once I have enough you'll receive an email detailing the new Plan 28 organization and how to actual send in the money.
3. Do you really think you can get 50,000 people to pledge?
Yes. Last year I got over 30,000 in the UK alone to sign the Alan Turing petition. This campaign is global and so I am confident that with the right exposure in the media and the help of enthusiastic people over 50,000 will pledge.
4. The Plan 28 web site is ugly.
Yes, I know. This is being actively worked on by a professional designer.
5. I have another idea about this.
Great. Contact me. I'm building up a big list of ideas, volunteers, etc. Would love to hear from you.
6. How can I help?
Sign the pledge. Tell people about this: tweet it, Facebook, email, etc.
7. Why hasn't someone done this before?
Because it takes time. It wasn't until the 1970s that Babbage's contributions were fully understood (see Bruce Collier's thesis), and until the 1980s that his plans had been deciphered by the likes of Allan Bromley. Only then could the Difference Engine No. 2 be constructed. It was finished in 1991. In many ways, The Difference Engine No. 2 was an 'easy' project because Babbage had left complete plans for it. The Analytical Engine is a different matter.
Babbage left multiple plans for the Analytical Engine and was constantly refining its design up until his death. To build the Analytical Engine first requires a research project to figure out which plan to build from. That's why the project has steps involving scanning all of Babbage's papers and a research project on them.
8. What's the best introduction to this project for a newbie?
Probably, the article The 100-year leap.
9. Why are you doing this?
In 1992 I sat on the floor of the Science Museum in London and watched the Difference Engine No. 2 demonstrated. And then I sat outside in the sun near the Natural History Museum and worked through its operation on paper. Since then I have been fascinated by Babbage and the fact that he had invented a real computer in 1837.
In 2000 the Science Museum completed the printer attachment for the Difference Engine No. 2 showing that Babbage's dream would have worked. I simply want to complete the task of honouring Babbage by creating his computer and showing it to the public.
1. Can I pledge more than $10/£10/€10?
Yes, of course! Many people have done so. The system doesn't have a box where you can enter an amount, but you can contact me and let me know, or, even better, publish a public comment with your pledge amount.
2. Can I pay you the money?
Not yet. Currently, I'm working on building up enough pledges to make sure this is viable. Once I have enough you'll receive an email detailing the new Plan 28 organization and how to actual send in the money.
3. Do you really think you can get 50,000 people to pledge?
Yes. Last year I got over 30,000 in the UK alone to sign the Alan Turing petition. This campaign is global and so I am confident that with the right exposure in the media and the help of enthusiastic people over 50,000 will pledge.
4. The Plan 28 web site is ugly.
Yes, I know. This is being actively worked on by a professional designer.
5. I have another idea about this.
Great. Contact me. I'm building up a big list of ideas, volunteers, etc. Would love to hear from you.
6. How can I help?
Sign the pledge. Tell people about this: tweet it, Facebook, email, etc.
7. Why hasn't someone done this before?
Because it takes time. It wasn't until the 1970s that Babbage's contributions were fully understood (see Bruce Collier's thesis), and until the 1980s that his plans had been deciphered by the likes of Allan Bromley. Only then could the Difference Engine No. 2 be constructed. It was finished in 1991. In many ways, The Difference Engine No. 2 was an 'easy' project because Babbage had left complete plans for it. The Analytical Engine is a different matter.
Babbage left multiple plans for the Analytical Engine and was constantly refining its design up until his death. To build the Analytical Engine first requires a research project to figure out which plan to build from. That's why the project has steps involving scanning all of Babbage's papers and a research project on them.
8. What's the best introduction to this project for a newbie?
Probably, the article The 100-year leap.
9. Why are you doing this?
In 1992 I sat on the floor of the Science Museum in London and watched the Difference Engine No. 2 demonstrated. And then I sat outside in the sun near the Natural History Museum and worked through its operation on paper. Since then I have been fascinated by Babbage and the fact that he had invented a real computer in 1837.
In 2000 the Science Museum completed the printer attachment for the Difference Engine No. 2 showing that Babbage's dream would have worked. I simply want to complete the task of honouring Babbage by creating his computer and showing it to the public.
Tuesday, October 12, 2010
1,000 people sign the Plan 28 pledge
A few moments ago I checked the Plan 28 pledge page to find that it had passed the 1,000 people mark. That took just 6 days. Thank you to everyone who's pledged so far (Peter Zuidhoek was the 1,000 person).
But even more heartwarming than the 1,000 are the comments people have been leaving on the page. You can read them all on the pledge page, but here are a few highlights. Many people have said that they'll pledge more than $10/£10/€10, with some going as high as $1,000. Brilliant.
Your pledges and comments are marvelous. Keep 'em coming!
PS If you want to know what this is all about visit Plan 28 or read The 100-year leap.
Related Hacker News discussion
But even more heartwarming than the 1,000 are the comments people have been leaving on the page. You can read them all on the pledge page, but here are a few highlights. Many people have said that they'll pledge more than $10/£10/€10, with some going as high as $1,000. Brilliant.
Worth it just for the first step. Do it for the next generation. -- Matt Doar
Put me down for a hundred quid. -- Aidan Karley
I have been hoping for years that someone would do this. I contributed to the construction of the Difference Engine and am proud to be able to contribute here. -- Raymond Woodward K3VSA
I'll pledge $100 - Roston McGregor
Great idea and willing to pledge more 50$ when the time comes -- Marcus Jaeger
Great endeavor, sign me up for $50 USD. -- Robert Huwar
I'd love to see this in action. I've seen the Difference Engine 2 at the Computer History Museum, and it's absolutely beautiful. I'm happy to pledge $1000. -- Eric Uhrhane
I hope this happens! $100 is yours. -- Christopher MacMurray
I will happily pledge way more than the $10. Best of luck. -- Noah Gildersleeve,
I'd love to see this happen. I pledge $100. -- Laurence Gonsalves
Your pledges and comments are marvelous. Keep 'em coming!
PS If you want to know what this is all about visit Plan 28 or read The 100-year leap.
Related Hacker News discussion
Monday, October 11, 2010
A big boost for Plan 28
Last night I appeared on TWiT with Leo Laporte and John C. Dvorak and guests. We talked about a lot of things late into my night, but mostly about Plan 28.
Leo encouraged listeners to pledge money and made the stunning offer of personally pledging $1,000 to the effort! And so, on top of Leo's pledge the number of people pledging has tripled!
Thanks Leo.
Leo encouraged listeners to pledge money and made the stunning offer of personally pledging $1,000 to the effort! And so, on top of Leo's pledge the number of people pledging has tripled!
Thanks Leo.
Sunday, October 10, 2010
Geek Weekend: Kew Bridge Steam Museum
So, I managed to persuade the people around me that it would fun to go and visit Kew Bridge Steam Museum, and it was brilliant! The museum is one of the places that was on the list for The Geek Atlas but got cut for space. Nevertheless, it's really worth visiting.
On weekends and other special days the folks at the museum set the machines running (including the massive 90 inch engine). I got there early enough to see most of the engines demonstrated and the staff were great. Got a good explanation of the operation of the triple expansion engine used for pumping water for London. Here it is in action:
Another nice engine is the Dancer's End engine that was used for pumping water on the estate of Lord Rothschild and was moved to the museum in the 1970s. And makes a lovely noise as the condenser water can be heard bubbling away. Here it is.
And finally, it's not all steam. There's a collection of Diesel engines. Here's a small one in action. What a brilliant sound.
There's also a steam train and Diesel train that run on a small track and are included in the price. And the ticket is valid for a year, so you can go back and see these wonderful engines in action as often as you can persuade your family to go with you.
On weekends and other special days the folks at the museum set the machines running (including the massive 90 inch engine). I got there early enough to see most of the engines demonstrated and the staff were great. Got a good explanation of the operation of the triple expansion engine used for pumping water for London. Here it is in action:
Another nice engine is the Dancer's End engine that was used for pumping water on the estate of Lord Rothschild and was moved to the museum in the 1970s. And makes a lovely noise as the condenser water can be heard bubbling away. Here it is.
And finally, it's not all steam. There's a collection of Diesel engines. Here's a small one in action. What a brilliant sound.
There's also a steam train and Diesel train that run on a small track and are included in the price. And the ticket is valid for a year, so you can go back and see these wonderful engines in action as often as you can persuade your family to go with you.
Friday, October 08, 2010
1,000 (bad) ideas
Tidying up my messy corner in the basement I unearthed one of my older "ideas books" in which I write down the random ideas that flit through my head quite frequently. Flicking through it I noticed that this book contained idea number 1,000 written on October 3, 2006. Most of these ideas never get implemented but they are fun to go back and read.
Idea 1,000 was In-ear headphones that automatically pause music when removed. The details mention using either a proximity detector to discover when the headphones are in the ear, or a strain gauge to detect the pressure of the ear canal.
The previous idea was Brake lights that show the severity of braking. The idea there was to replace the current 'high-level' brake lights in cars (that are typically a horizontal bar), with a triangle of lights. Under normal braking just the top, horizontal red bar would illuminate. Under heavy braking the triangle would illuminate warning drivers of an emergency situation (particularly useful on motorways at high-speed). Since the red triangle is a common warning symbol this would be instantly recognizable.
I've been filling these books since about 1992. By 2006 I'd had 1,000 (bad) ideas, which works out to about one every five days. Some of them I've implemented (such as l8tr), others I've seen implemented by other people: there's an amusing entry from 1995 about building a networked disk drive service that I wanted to call "I-Drive". The plan was to use FTP as the underlying protocol and make a drive (I:) appear in Windows 95. I: would actually be on the Internet and could be accessed by multiple machines.
The idea I'm most pleased with is my book, The Geek Atlas, because it was (fairly) original. No one else had written "Lonely Planet for Nerds". Overall, perhaps 10 of my 1,000 ideas look like they might be 'good ideas'.
Does anyone else generate ideas like this? And if so, what percentage turn out to be good?
Related Hacker News discussion
Idea 1,000 was In-ear headphones that automatically pause music when removed. The details mention using either a proximity detector to discover when the headphones are in the ear, or a strain gauge to detect the pressure of the ear canal.
The previous idea was Brake lights that show the severity of braking. The idea there was to replace the current 'high-level' brake lights in cars (that are typically a horizontal bar), with a triangle of lights. Under normal braking just the top, horizontal red bar would illuminate. Under heavy braking the triangle would illuminate warning drivers of an emergency situation (particularly useful on motorways at high-speed). Since the red triangle is a common warning symbol this would be instantly recognizable.
I've been filling these books since about 1992. By 2006 I'd had 1,000 (bad) ideas, which works out to about one every five days. Some of them I've implemented (such as l8tr), others I've seen implemented by other people: there's an amusing entry from 1995 about building a networked disk drive service that I wanted to call "I-Drive". The plan was to use FTP as the underlying protocol and make a drive (I:) appear in Windows 95. I: would actually be on the Internet and could be accessed by multiple machines.
The idea I'm most pleased with is my book, The Geek Atlas, because it was (fairly) original. No one else had written "Lonely Planet for Nerds". Overall, perhaps 10 of my 1,000 ideas look like they might be 'good ideas'.
Does anyone else generate ideas like this? And if so, what percentage turn out to be good?
Related Hacker News discussion
Thursday, October 07, 2010
The Analytical Engine vs. The ZX81
Many people got started with computing in my age group with the Sinclair ZX81 (which in the US was sold as the Timex Sinclair 1000).
Reading through Allan Bromley's excellent papers on Babbage's Analytical Engine (as described in 1847) I thought it might be fun to compare the two machines.
The ZX81 has 1KB of memory in which programs and data had to be stored. The Analytical Engine as first imagined would have had 50 variables capable of each storing a 30 digit decimal number. That's equivalent to each variable having 100 bits and hence the memory for the Analytical Engine would have been 5000 bits (675 bytes). Later Babbage proposed much larger memory sizes with up to 50 decimal digits per variables and 1000 variables: that would have been a memory of 166 bits per variable or over 20 KB of memory.
Critically, the Analytical Engine's programs would be stored on punched cards and executed directly from them so that entire memory space was for data (not the program). In contrast the ZX81 had to load the program from magnetic tape into its 1KB of RAM.
But the ZX81 was much, much faster than Babbage's machine. It had a clock speed of 3.25 MHz. The Analytical Engine was based around a standard cycle time of 1/7s which is the same as 7Hz. To get an idea of the speed of the machines, here's a comparison of a 100 bit add on the two machines.
On the Analytical Engine it would take about three seconds to fetch the two numbers from memory (the store) and perform the addition. Although this is long Babbage added the ability to do a pipeline of multiple additions with overlapped reads from memory and addition happened in parallel. The ZX81 does not have that ability.
On the ZX81 in Z80 assembler a 100 bit addition (which I've done as 13 8-bit additions here) could be implemented as follows. I've assumed that IX and IY are pointing to the operands in memory and that the result will be stored in the memory addressed by IY.
Each instruction there takes 19 clock cycles and there are a total of 39 instructions giving 741 clock cycles. With the Z80 running at 3.25MHz that set of instructions takes 0.228 ms. So for that addition the ZX81 would have been 13,000x faster.
Obviously, this is slightly bogus because there are other more complex and slow instructions in the Analytical Engine (such as division) but it gives an idea of the scale.
So, the ZX81 had much less RAM than the Analytical Engine (and who doesn't remember all the trouble of fitting everything into RAM on those machines) and was forced to use it to hold programs, but the Analytical Engine was slow in comparison.
PS If you'd like to see the Analytical Engine built, read this.
Reading through Allan Bromley's excellent papers on Babbage's Analytical Engine (as described in 1847) I thought it might be fun to compare the two machines.
The ZX81 has 1KB of memory in which programs and data had to be stored. The Analytical Engine as first imagined would have had 50 variables capable of each storing a 30 digit decimal number. That's equivalent to each variable having 100 bits and hence the memory for the Analytical Engine would have been 5000 bits (675 bytes). Later Babbage proposed much larger memory sizes with up to 50 decimal digits per variables and 1000 variables: that would have been a memory of 166 bits per variable or over 20 KB of memory.
Critically, the Analytical Engine's programs would be stored on punched cards and executed directly from them so that entire memory space was for data (not the program). In contrast the ZX81 had to load the program from magnetic tape into its 1KB of RAM.
But the ZX81 was much, much faster than Babbage's machine. It had a clock speed of 3.25 MHz. The Analytical Engine was based around a standard cycle time of 1/7s which is the same as 7Hz. To get an idea of the speed of the machines, here's a comparison of a 100 bit add on the two machines.
On the Analytical Engine it would take about three seconds to fetch the two numbers from memory (the store) and perform the addition. Although this is long Babbage added the ability to do a pipeline of multiple additions with overlapped reads from memory and addition happened in parallel. The ZX81 does not have that ability.
On the ZX81 in Z80 assembler a 100 bit addition (which I've done as 13 8-bit additions here) could be implemented as follows. I've assumed that IX and IY are pointing to the operands in memory and that the result will be stored in the memory addressed by IY.
LD A,(IX+0)
ADD A,(IY+0)
LD (IY+0),A
LD A,(IX+1)
ADC A,(IY+1)
LD (IY+1),A
LD A,(IX+2)
ADC A,(IY+2)
LD (IY+2),A
[...]
LD A,(IX+12)
ADC A,(IY+12)
LD (IY+12),A
Each instruction there takes 19 clock cycles and there are a total of 39 instructions giving 741 clock cycles. With the Z80 running at 3.25MHz that set of instructions takes 0.228 ms. So for that addition the ZX81 would have been 13,000x faster.
Obviously, this is slightly bogus because there are other more complex and slow instructions in the Analytical Engine (such as division) but it gives an idea of the scale.
So, the ZX81 had much less RAM than the Analytical Engine (and who doesn't remember all the trouble of fitting everything into RAM on those machines) and was forced to use it to hold programs, but the Analytical Engine was slow in comparison.
PS If you'd like to see the Analytical Engine built, read this.
Wednesday, October 06, 2010
Let's raise £500k for the Analytical Engine
If you are new to this please read my introduction to Babbage's 100-year Leap. If not, read on...
I've created a PledgeBank entry for the project here where I'm asking people to pledge to donate $10/£10/€10 towards a non-profit organization dedicated to building the Analytical Engine. The non-profit would have four goals:
1. To help digitize and make available in electronic form all of Charles Babbage's notes and plans associated with the Difference Engine and Analytical Engine.
2. To fund the study of Babbage's Analytical Engine plans to determine what best constitutes a complete design for the Engine.
3. To coordinate the building of a computer simulation of the Analytical Engine that shows its working in 3D with accurate physics.
4. To build the Analytical Engine and donate it to a museum in Great Britain for public display.
PledgeBank operates on an all-or-nothing system where I either reach the goal and then can ask people to make good on their pledge, or I fail. Please consider signing up to pledge $10/£10/€10 towards these goals.
I've created a PledgeBank entry for the project here where I'm asking people to pledge to donate $10/£10/€10 towards a non-profit organization dedicated to building the Analytical Engine. The non-profit would have four goals:
1. To help digitize and make available in electronic form all of Charles Babbage's notes and plans associated with the Difference Engine and Analytical Engine.
2. To fund the study of Babbage's Analytical Engine plans to determine what best constitutes a complete design for the Engine.
3. To coordinate the building of a computer simulation of the Analytical Engine that shows its working in 3D with accurate physics.
4. To build the Analytical Engine and donate it to a museum in Great Britain for public display.
PledgeBank operates on an all-or-nothing system where I either reach the goal and then can ask people to make good on their pledge, or I fail. Please consider signing up to pledge $10/£10/€10 towards these goals.
Charles Babbage and Climate Change
At the risk of turning into James Burke and creating my own version of Connections, it's amusing to know that two of the topics I've blogged about, Charles Babbage and Climate Change, have a strong connection.
One of the key areas of climate change research used to demonstrate the we live in historically overheated times is dendrochronology (looking at tree rings) to determine past climate (called dendroclimatology). This is a large part of the science behind the Hockey Stick and related controversy.
So, who's the father of dendroclimatology? Charles Babbage has a strong claim.
Babbage wrote in 1838:
One of the key areas of climate change research used to demonstrate the we live in historically overheated times is dendrochronology (looking at tree rings) to determine past climate (called dendroclimatology). This is a large part of the science behind the Hockey Stick and related controversy.
So, who's the father of dendroclimatology? Charles Babbage has a strong claim.
Babbage wrote in 1838:
It is well known that dicotyledonous trees increase in size by the deposition of an additional layer annually between the wood and the bark, and that a transverse section of such trees presents a series of nearly concentric though irregular rings, the number of which indicates the age of the tree. The relative thickness of these rings depends on the more or less flourishing state of the plant during the years in which they were formed.
[...]
These prominent effects are obvious to our senses, but every shower that falls, every change of temperature that occurs, and every wind that blows, leaves on the vegetable world the traces of its passage; slight, indeed, and imperceptible, perhaps, to us, but not the less permanently recorded in the depths of those woody fabrics. All these indications of the growth of the living tree are preserved in the fossil trunk, and with them also frequently the history of its partial decay.
Let us now inquire into the use we may make of these details relative to individual trees, when examining forests submerged by seas, embedded in peat mosses, or transformed, as in some of the older strata, into stone. Let us imagine, that we possessed sections of the trunks of a considerable number of trees, such as those occurring in the bed called the Dirt-bed in the island of Portland. If we were to select a number of trees of about the same size, we should probably find many of them to have been contemporaries. This fact would be rendered probable if we observed, as we doubtless should do, on examining the annual rings, that some of them conspicuous for their size occurred at the same distances of years in several trees. If, for example, we found on several trees a remarkably large annual ring, followed at the distance of seven years by a remarkably thin ring, and this again, after two years, followed by another large ring, w¨ should reasonably infer that seven years after a season highly favourable to the growth of these trees, there had occurred a season peculiarly unfavourable to them; that after two more years anotherveryfavourable season had happened, and that all the trees so observed had existed at the same period of time. The nature of the season, whether hot or cold, wet or dry, might be conjectured with some degree of probability, from the class of tree under consideration.
[...]
The means of identifying the influence of differentt seasons in various: sections of the same individual tree an its branches being thus attained, the conclusions arrived at must be applied to several trees under similar circumstances, and such modifications must be applied to them as the case may require; and before any general conclusions can be reached respecting a tract of country once occupied by a forest, it will be necessary to have a considerable number of sections of trees scattered over various parts of it.
Tuesday, October 05, 2010
Three Silicon Valley places Paul Graham omitted
Paul Graham came up with a good list of places to see Silicon Valley, but to my mind he missed three important places from a historical perspective. One of these is a major omission because it put the Silicon in Silicon Valley.
1. The HP Garage
Paul mentions walking around Old Palo Alto but doesn't include 367 Addison Avenue where HP got started. Working out in the garage of the house where Dave Packard lived, William Hewlett designed HP's first product: The Model 200A oscillator. Notice how they were great at marketing: they called it the Model 200A to make it look like it was one of a number of products from a big company.
© BrokenSphere / Wikimedia Commons
The Model 200A was a cheap audio oscillator that undercut competing products and contained a wonderful hack. To solve a common problem with the oscillator type that underlies the Model 200A (a Wien-bridge) Hewlett needed a resistance that would automatically vary to prevent the amplitude of oscillation from rising too high (and causing clipping). He replaced a fixed resistance in the circuit with a lamp. As the amplitude increases the bulb shines brighter and its resistance increases. The lamp resistance forms part of a voltage divider and the increased resistance lowers the voltage bringing the amplitude under control.
2. The Shockley Building
Although it's now a shop, the place that put Silicon in Silicon Valley is the building that housed Shockley Semiconductor. In 1956 William Shockley moved to Silicon Valley (where his mother lived) and started a company to produce silicon, rather than germanium, transistors.
The building is at 391 San Antonio Road in Mountain View. Be sure to get your photo taken next to the historic marker.
Mostly because Shockley was a difficult person his company fell apart and a large number of employees went off to form Fairchild.
3. The Fairchild Building
This is another photo opportunity with a historic marker. The original Fairchild building is at 844 Charleston Road in Palo Alto and its here that the integrated circuit was invented (using the planar process). The planar process is the familiar method used to produce integrated circuits to this day by repeatedly doping a piece of silicon to process N-type and P-type regions through a photographic mask. It was far more efficient that Texas Instruments' mesa process.
All three places, of course, are in The Geek Atlas. And all three are very close together in Palo Alto and Mountain View. You can easily visit all three in an afternoon.
1. The HP Garage
Paul mentions walking around Old Palo Alto but doesn't include 367 Addison Avenue where HP got started. Working out in the garage of the house where Dave Packard lived, William Hewlett designed HP's first product: The Model 200A oscillator. Notice how they were great at marketing: they called it the Model 200A to make it look like it was one of a number of products from a big company.
The Model 200A was a cheap audio oscillator that undercut competing products and contained a wonderful hack. To solve a common problem with the oscillator type that underlies the Model 200A (a Wien-bridge) Hewlett needed a resistance that would automatically vary to prevent the amplitude of oscillation from rising too high (and causing clipping). He replaced a fixed resistance in the circuit with a lamp. As the amplitude increases the bulb shines brighter and its resistance increases. The lamp resistance forms part of a voltage divider and the increased resistance lowers the voltage bringing the amplitude under control.
2. The Shockley Building
Although it's now a shop, the place that put Silicon in Silicon Valley is the building that housed Shockley Semiconductor. In 1956 William Shockley moved to Silicon Valley (where his mother lived) and started a company to produce silicon, rather than germanium, transistors.
The building is at 391 San Antonio Road in Mountain View. Be sure to get your photo taken next to the historic marker.
Mostly because Shockley was a difficult person his company fell apart and a large number of employees went off to form Fairchild.
3. The Fairchild Building
This is another photo opportunity with a historic marker. The original Fairchild building is at 844 Charleston Road in Palo Alto and its here that the integrated circuit was invented (using the planar process). The planar process is the familiar method used to produce integrated circuits to this day by repeatedly doping a piece of silicon to process N-type and P-type regions through a photographic mask. It was far more efficient that Texas Instruments' mesa process.
All three places, of course, are in The Geek Atlas. And all three are very close together in Palo Alto and Mountain View. You can easily visit all three in an afternoon.
Monday, October 04, 2010
The 100-year leap
Here's something I wrote for O'Reilly Radar:
Read on.
In December 1837, the British mathematician Charles Babbage published a paper describing a mechanical computer that is now known as the Analytical Engine. Anyone intimate with the details of electronic computers will instantly recognize the components of Babbage's machine. Although Babbage was designing with brass and iron, his Engine has a central processing unit (which he called the mill) and a large amount of expandable memory (which he called the store). The operation of the Engine is controlled by program stored on punched cards, and punched cards can also be used to input data.
Read on.
GAGA-1: Computer mounting
Not much time to work on GAGA-1 this weekend, so I nailed down one of the simpler items: how the two computers (flight and recovery) are going to be mounted inside the capsule. After considering all sorts of techniques I settled on self-adhesive Velcro "coins" and a cut up fast food container (the plastic containers that much Indian food comes in have nice fitting lids and are made of strong plastic: I use them for storing screws, components and all the miscellaneous stuff in my basement).
Here's a picture of an untouched curry container and once I cut up. The two black dots are Velcro pads on I stuck on the bottom. The container is just the right width to fit in the box and the small vertical portion pushes against the edges of the box keeping it snug. Between that and the Velcro this will provide adequate support for the two computers.
With the two computers sitting on it, it's clear that there's adequate space. The computers will be attached using screws and risers that I have left over from an ancient robot project.
Finally, here's a shot inside the capsule itself showing the Velcro pads that are stuck directly to the polystyrene.
The other thing I spent time on was deciding on interfacing for the Telit GSM862 module. I toyed with the idea of buying a SparkFun USB Evaluation Board to make the module easy to program, but the price put me off. It's very expensive just to get a USB interface.
Since the module will be flown attached to a simple breakout board (see the photo above), I decided that I'll interface directly to that board for programming using a USB TTL converter cable. That way I can program the device in place... cheaply. The breakout board will only have three additional things attached to it: power, an LED on the STAT_LED pin, and a simple switch on the ON/OFF pin.
Note that in the circuit diagram for the SparkFun GSM862 Basic Evaluation Board (the breakout board I'm using), it's not obvious that all four of the VCC connections on the Telit module are connected together, and both the GND connections are connected together. This is super convenient because it means only one of each needs to be connected to the battery, but the SparkFun circuit diagram is incorrect in showing six separate connections. A quick test with a multimeter and a look at the PCB tracks verifies the truth.
Here's a picture of an untouched curry container and once I cut up. The two black dots are Velcro pads on I stuck on the bottom. The container is just the right width to fit in the box and the small vertical portion pushes against the edges of the box keeping it snug. Between that and the Velcro this will provide adequate support for the two computers.
With the two computers sitting on it, it's clear that there's adequate space. The computers will be attached using screws and risers that I have left over from an ancient robot project.
Finally, here's a shot inside the capsule itself showing the Velcro pads that are stuck directly to the polystyrene.
The other thing I spent time on was deciding on interfacing for the Telit GSM862 module. I toyed with the idea of buying a SparkFun USB Evaluation Board to make the module easy to program, but the price put me off. It's very expensive just to get a USB interface.
Since the module will be flown attached to a simple breakout board (see the photo above), I decided that I'll interface directly to that board for programming using a USB TTL converter cable. That way I can program the device in place... cheaply. The breakout board will only have three additional things attached to it: power, an LED on the STAT_LED pin, and a simple switch on the ON/OFF pin.
Note that in the circuit diagram for the SparkFun GSM862 Basic Evaluation Board (the breakout board I'm using), it's not obvious that all four of the VCC connections on the Telit module are connected together, and both the GND connections are connected together. This is super convenient because it means only one of each needs to be connected to the battery, but the SparkFun circuit diagram is incorrect in showing six separate connections. A quick test with a multimeter and a look at the PCB tracks verifies the truth.
Start The Engine
I woke up this morning to discover that the The Independent newspaper in the UK had picked up on my desire to build Babbage's Analytical Engine (see Plan 28) with not one, but two articles. The first article begins:
But the real surprise was that they decided to talk about the Engine in a Leader titled Start the engine:
PS Amusingly, The Daily Mail has picked up the story here without speaking to me at all.
It may seem an anachronism in the era of the ever-shrinking digital gadget, but Charles Babbage's locomotive-size "Analytical Engine" remains one of the greatest inventions that never was.
Babbage's brainchild, first conceived in 1837, never wound into life. But now John Graham-Cumming, an influential programmer and science blogger, is leading a quest to build the Analytical Engine in all its 19th-century glory. He plans to use detailed blueprints which Babbage laid down in a series of notebooks held in the archives of London's Science Museum.
But the real surprise was that they decided to talk about the Engine in a Leader titled Start the engine:
John Graham-Cumming led the successful campaign last year to secure a pardon for Alan Turing. Now the science blogger intends to deliver a posthumous honour for another of the fathers of computing: Charles Babbage. Mr Graham-Cumming's latest project is to build Babbage's "Analytical Engine" – essentially a great steam-powered computer – based on the 19th-century inventor's designs held by the Science Museum.
PS Amusingly, The Daily Mail has picked up the story here without speaking to me at all.
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