Raspberry Pi – 2006 edition

Many people have asked us whether it’s possible to hand-assemble a Raspberry Pi. While the use of fine-pitch BGAs and PoP memory make this impossible, I thought you might like to see how one of my home-made prototypes of a $25 computer looked back in 2006, before I gave up on DIP chips, through-hole components and veroboard.

Veroboard and PCB versions of the prototype

These boards use an Atmel ATmega644 microcontroller clocked at 22.1MHz, and a 512K SRAM for data and framebuffer storage. 19 of the Atmel’s 32 GPIO lines are used to drive the SRAM address bus. To generate a 320×240 component video signal, the Atmel rapidly increments the address, and the data lines are fed via 74HC-series buffers to a trio of simple summing-point DACs; during horizontal and vertical blanking, it is free to perform other operations. Here’s a video of the device in action.

Not quite Quake 3, I’m sure you’ll agree, but maybe familiar to fans of David’s 1987 classic Zarch. In the end, I felt that much higher performance, and the ability to run a general-purpose operating system, outweighed the benefits of home assembly, but it’s still a neat design. Those of you interested in the gory details can download Easy-PC schematics and a PCB layout here.

46 comments

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Nice assembly job there. I am nowhere near that neat with the nerdkit i just bought and am learning to use. If the BCM2835 was pre-mounted on a board it would be possible to carry out at least some of the work. It is the fine pitch of the components that make it hard. It would be nice if someone could figure out a modular system that would allow pre-mounted components to be linked into a working design.

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I know I’m meant to answer the questions round here rather than ask them – but is that the biggest piece of veroboard you can buy?

eben

It’s the biggest piece of veroboard *I* could buy. Don’t think I didn’t look for a larger piece :)

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You mean you didn’t make your own? a 3′ x 3′ piece of peg board and some aluminium foil and you are all set.

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If you need it for anything, then there are many sellers of veroboard of size 18 x 30 cm on eBay. I didn’t count the holes on the photo to see if Eben’s piece is longer than that though. :)

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I make it 118×39 holes, though I only counted once. ;-) So that’s almost 12″, Eben.

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Cool pictures. Now we just need to see pictures of the 2011 version :-)

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You forgot the part where you wash the peg board in hot water then dry it on high so the holes shrink!

@eben You should have went really old school and tried that point-to-point. Or wire wrap.

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My favorite ‘old school’ trick was to glue DIP components to a substrate and then use wire to connect the legs… Using some single sided PCB was great for a ground plane! Could make really high frequency stuff that way (I mean proper 10MHz stuff!!!) Try that with BC107’s brings back the memories…

Also remember wiring up a 19″ rack with wirewrap, by hand… No fun there…

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ECC86 …

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Wait … so the video controller and the CPU were the same processor, and the processor was busy feeding scanlines most of the time and did the actual CPU work during blank?

eben

Yep. Not quite as cool as the NOP trick on the ZX80 and ZX81, but there’s some subtlety involved in permitting hardware scrolling when your code is in ROM (no self-modifying code) and you can only modify 8 address bits atomically (so how do you count from 0ffh to 100h?).

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Very interesting! But what I’m more interested in are the final Raspi production boards. When do you think we can see the first pictures and is there any planning on the release yet?

Keep it up!

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If you read the FAQ’s… you would see that the release is near the end of November.

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My ti84 calculator does better 3d graphics lol

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Hmmm… I hardly doubt Debian ‘ll run on that thing… XD

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That’s great, I kind of want one. I guess a RasPi will just have to do.

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[…] of the computer). The Raspberry Pi is expcted to cost $25 when it goes on sale in the near future.[Raspberry Pi blog]Posts Related to Build your own prototype Raspberry Pi minicomputerRIM out to rev up BlackBerry […]

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Would it be possible to get a pdf, jpg, or tiff image of the schematic for this? I would love to build one to play with but I do not have Easy-PC schematic program and it wouldn’t run on my computer when I downloaded it last night. I run linux and tried to run it under wine and it just kept locking up and didn’t like me and I have no windows boxes here to run it on.

Thanks,
Ray Moore
ray@bethnray.com

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Don’t worry that it didn’t run for you. the demo version won’t print or export anyway as those functions are only available on the full paid for version.

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So, then, no pdf or jpg or tiff schematic?

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I’m assuming when you say “component video” you mean “composite video” and not a YPbPr thingy?

Nice to see chasing-the-raster was still in use in 2006 =)

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>>the use of fine-pitch BGAs and PoP memory make this impossible…

That’s possible, though really tricky. My friend repairs tons of smartphones & PDAs, and he does fine-pitch BGA soldering every day. All you need is VERY straight hands, high-quality thermal fan and good soldering chemicals.

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OK, impossible for all but a very few very skilled people with the right equipment.

(Although I’m not sure you can manually solder on a PoP memory)

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I would love to see something like this though using a 44 or 64 pin LQFP ARM at 160Mhz to 400MHz, or perhaps an AVR32 (at 66MHz). The small ARM chips can be had for around $5USD, and while they do not have an external address and data bus, it is still possible to create one that does not take much from the CPU using the DMA and outputting counters to some GPIO pins. Perhaps Raspberry Pi could this type of thing to help appeal to those that are interested in electronic HW, and/or robotics.

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Very unlikely; the purpose of the foundation is to teach programming, not a particular electronics or other low level activities.We therefore need a machine that can run at a higher level than what you suggest.

However, as you are aware, its perfectly possible to built once of those type of boards yourself.

$5 isn’t much less than what the Raspi SoC costs anyway – the majority of the Pi cost is PCB and plugs. So any boards would only be a $1 or bit less.

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I am a missionary Benedictine with a project using older computers and lumbuntu for education in the poor schools of Guatemala. I am very interested in your project. I am a Rotary member and would like to submit a program using your 35 dollar version with solar panels and perhaps a laser projector. I see they made the breakthrough with the green laser cheaply. Maxim 3500b is a driver. perhaps a great combination. I have a friend Chuck Colby who is also interested in helping me. I would appreciate hearing from you. Bernardino Ness

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What great ideas, very disappointing that for tax reasons can not be built in the UK, how stupid is that??
I remember assembling a Sinclair ZX 81 how short sighted I was?!
I wish you great success & the UK.

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Tax isn’t the only reason – it’s the straw that broke the camels back.

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[…] [Eben has posted a photo, video and the schematics of a version from 2006 on the raspberry pi website. […]

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[…] [Eben has posted a photo, video and the schematics of a version from 2006 on the raspberry pi website. […]

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Rasberry Pi, great idea. I used do to all of this in primary education in the 80’s and welcome the return. But as long as there are league tables that only value maths, English and Science there will always be a brake on this initiative in primary schools. In the meanwhile I will do what I can!

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[…] he gained at his day job as an engineer for system-on-chip specialist Broadcom to develop a Veroboard-based prototype with a Atmel ATMega644 microcontroller running at just 22.1MHz and with 512K of […]

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[…] he gained at his day job as an engineer for system-on-chip specialist Broadcom to develop a Veroboard-based prototype with a Atmel ATMega644 microcontroller running at just 22.1MHz and with 512K of […]

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[…] he gained at his day job as an engineer for system-on-chip specialist Broadcom to develop a Veroboard-based prototype with a Atmel ATMega644 microcontroller running at just 22.1MHz and with 512K of […]

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Eine tolle Idee !!!!

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[…] system passion for by recapturing the programming frontier spirit of the BBC Micros of old. Seven years later and the boards are ready, compact and bristling with ports and […]

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Hiya, just stumbled upon this tech and website when surfing for computer parts. (I build and fix them in my spare time/ Telecoms Engineer – full time career. Erm I gotta admit quite a noob to this kinda stuff, but totally hooked already! So I will apologise in advance in case I ask any dumb questions. Im learning from scratch so any tips, advice, links are much appreciated. Cool website, tech and info, keep up the good work, catch you soon. :o)

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My son’s trying without succes to “his” invention working. Seeing/buying you example willsolve a lot of problems. Hopoe to see them soon in yr Shop.
Ciao,
Maarten Italy

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Hello

Is the schmatic, part list and source code for the 2006 Edition downloadable anywhere as I would like to have a go at building one???
Thanks

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[…] aqui você poderá ver as fotos dos primeiros projetos do Raspberry Pi ou o site da comunidade. No site da fundação os fundadores deixaram a seguinte menssagem: […]

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I was looking this product and thinking wow I remember writhing for the spectrum computer system. At primary school I remember the computer system there which used the old huge floppy disk drives. I would like to have a stab at programming again and was wondering when will the raspberry pi be on sale in the uk? Also will it be able to be supplied to schools? I would like to buy a couple of units for my old primary and secondary schools.
Thank you so much for your time.
Kind regards
Craig milsted

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On sale now from RS and Farnell. There will be a schools release in Q3. Check out the FAQ for more details.

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It’s nice to see the humble beginnings of the Raspberry Pi, but where do I buy one?

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Great to see the prototype boards, thanks for sharing…

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That takes me back. I was doing that with Motorola 6800 processors in the early 80s.
Of course once I progressed to MC68HC microcontrollers in the early 90s the projects were a lot smaller. Our company must have shipped 30,000 products with HC705J1A chips in them.
All code written in assembler too. Try fitting a network stack into 1K of codespace!

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