Ask Hackaday: Who Likes Retrocomputing?

September 15, 2012 by Brian Benchoff 54 Comments

Last week we posted a link to Project Kiwi, a homebrew Motorola 68008-based microcomputer built by [Simon] that includes Ethernet, a very good display adapter, an interface for IDE hard disks, two Commodore SID chips (for stereo chiptunes), a floppy disk controller, and an already existent software library that will make it very easy to develop your own software for this wonderful computer.

After thinking about [Simon]’s Project Kiwi for a while, I’ve been thinking there really hasn’t been a homebrew computer made that is so perfect for a proper Open Hardware release. There are more than enough peripherals in the computer to make development very fun. I’ve suggested doing a group buy to get Kiwi PCBs out into the wild and into the hands of other retrocomputer fanatics, but [Simon] would like a little more feedback.

Of course, this means turning to you, the wonderful Hackaday reader. Would any of you be interested in your own Kiwi microcomputer?

[Simon] tells me there are a lot of problems for turning the Kiwi microcomputer into a Open Hardware project. His prototype PCB cost €300, greatly reducing the number of people who would be interested in making their own Kiwi. Also, there are a few problems on the current PCB design (easily fixed for the next revision), and [Simon] would like to add a few features like DMA and a proper framebuffer.

Despite all those problems, I can’t see a better way to learn about computer architecture the hard way (i.e. 80’s microcomputers as opposed to futzing around with a Raspberry Pi). You’ll also get a really wonderful computer system that will show the power of 80s-era electronics, with the very hopeful goal of spreading the gospel of retrocomputing with the venerable Saint MC68000.

If you’d like to add your two cents – if having an Open Hardware 80s microcomputer is a good idea, or some technical requests such as adding a proper 68000 CPU to future designs, leave a note in the comments or on the forum [Simon] set up on his Kiwi page.

I think it’s a cool idea, but then again I’m probably blinded by how cool an 80s computer of this caliber is. The fate of this project is now in your hands.

Homebrew 68k Extravaganza

September 4, 2012 by Brian Benchoff 45 Comments

Introduced in 1979, the Motorola 68000 CPU was first used in very expensive and very high-end workstations from the likes of Sun and SGI. As the processor matured it became well-known for its use in the original Macintosh, early Amigas, and even the TI-89 graphing calculator and a few video game consoles such as the Sega Genesis and Atari Jaguar.

A few days ago when I posted a homebrew computer build based on the 65816 CPU, I lamented the lack of builds using the venerable Motorola 68k. Hackaday readers were quick to point out the many homebrew computers making use of this classic CPU, and I’m glad to post them here.

First up is an amazing 68008 build featuring an IDE disk interface, a floppy disk interface, 10base-T Ethernet connectivity, a real-time clock, and two SID synthesizer chips. As far as features go, this build takes the cake. Pity I can’t find a writeup.

Here’s a 68000-based computer built around the S-100 bus. Like the first computer to use the S-100 bus, the Altair 8800, this computer is plugged into a backplane that breaks out the data, address, and interrupt lines to every device on the bus.

Of course, no mention of backplane computers would be complete without a Eurocard version. [N8VEM] built a 68000 computer able to be plugged in to a backplane along with an IDE controller card and a display controller.

Finally, in true ‘giant mess of wires’ spirit, [Dajgoro] sent in his 68k single board computer featuring 512 kB of RAM and a 16k ROM. [Dajgoro] also took the time to wire in a PIC microcontroller, allowing him to expand his computer far beyond what vintage components would allow.

The 68k was – and still is – a very powerful CPU that far surpasses the capabilities of the 6502 and Z80 homebrew computers we see from time to time. Short of building a 486 or Pentium-based computer from scratch, building a 68k machine is one of the crowning achievements of hardware hackery, and something we hope to see more of in the future.