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Linux On a Motorola 68000 Solder-less Breadboard
New submitter lars_stefan_axelsson writes: When I was an undergrad in the eighties, "building" a computer meant that you got a bunch of chips and a soldering iron and went to work. The art is still alive today, but instead of a running BASIC interpreter as the ultimate proof of success, today the crowning achievement is getting Linux to run: "What does it take to build a little 68000-based protoboard computer, and get it running Linux? In my case, about three weeks of spare time, plenty of coffee, and a strong dose of stubbornness. After banging my head against the wall with problems ranging from the inductance of pushbutton switches to memory leaks in the C standard library, it finally works! (video)"
No, a Wang would be based on the older 8086 processor, this machine uses a 68000.
Hats off. The 68000 was the first CPU owned (Atari ST) and I had a good six years of assembly skills behind me when it was finally time to leave. Awesome CPU for the kind of magic demo tricks only hard core assembler coding could bring out.
Relevant discussion: http://compgroups.net/comp.os....
it's in my head
Thanks for all the comments! This "68 Katy" is my project. The video is a good overview, and lots more tech details are at http://bigmessowires.com/2014/... and the rest of the site. I've built a couple of other home-made CPU / computer projects in the past, including "Big Mess o' Wires" a few years ago, but this was the first time I tried to add a real OS. Cramming Linux into 512K was a challenge!
The CPU is a 68008, which is a low cost version of the familiar 68000 with an 8-bit bus and fewer external address pins. It has a max of 1 MB of total address space. It’s paired with a 512K 8-bit SRAM, and a 512K Flash ROM (of which 480K is addressable – the remaining 32K is memory-mapped I/O devices). My 68008 runs at 2 MHz (it was unstable when tested at 4 MHz), providing similar performance to a 1 MHz 68000. That’s pretty slow, even in comparison to 68000 systems from the early 1980s, which were typically 8 MHz or faster. So frame rates in the latest games aren't great...
The 68008 was discontinued 20 years ago, so this isn't really all that useful even as an educational exercise. Why not pick a current breadboardable, cheap microprocessor and get Linux to run on that? That way, other people can benefit.
Why even bother with hardware. Why not just emulate it?
But then again .. why emulate it when you can buy time on a virtual system?
Then again why do all that when you could just be watching TV?
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