So Many Replicas!

[sje]

I have one of Vince's Micro-KIM boards and it works as advertised. I'll probably get one of his 32 KB expansion boards to go with it.

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I'm continuing with my design for a 6502 (W65C02S specifically) system with a classical front panel. I'd probably not bother with this if there were some way of getting a new (kit or built) IMSAI 8080 or Altair 8800b. At the moment I'm waiting for parts. Eventually I'll make the schematic and BOM available.

[Geoff Harrison]

Originally Posted by sje

I'd probably not bother with this if there were some way of getting a new (kit or built) IMSAI 8080 or Altair 8800b.

David Griffith has a fairly nice IMSAI up on eBay right now. No disks, though.

Geoff.

[Grant Stockly]

Originally Posted by sje

I have one of Vince's Micro-KIM boards and it works as advertised. I'll probably get one of his 32 KB expansion boards to go with it.

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I'm continuing with my design for a 6502 (W65C02S specifically) system with a classical front panel. I'd probably not bother with this if there were some way of getting a new (kit or built) IMSAI 8080 or Altair 8800b. At the moment I'm waiting for parts. Eventually I'll make the schematic and BOM available.

What about doing something with the 65C816? There is an affordable 512kbyte SRAM DIP too. You could use the $6 flash chips I used with the 680 to give it 512kbyte of eeprom style flash.

[sje]

Yes, the W65C816S was considered. And it still could be used in a modified design. But it just doesn't seem sufficiently retro!

[Grant Stockly]

I've been thinking about building an SBC out of all DIP parts that could run linux. Using a 64pin 68000, 32pin 512kb SRAM, etc. An inexpensive kit that has something in common with modern tools and software would be fun. A true "modern" computer kit. I wanted to limit it to DIP/PLCC/through hole parts since even coarse pitch SOIC parts are hard for some people.

I have had this idea since before the Altair kit ever came. Now I'm thinking it would be neat to have a 68000 and some memory on an S-100 card so that the Altair can run linux.

I know of at least one case where uCLinux has run on a 68000, but the FPGA company who built it for their core doesn't want to share the kernel patches.

I only suggest the 65816 because there are already a few 6502 kits out there.

I've been thinking about selling my Altair 8800 kit prototype. Its taking up space and I don't think I need to keep it for "memories". If you or anyone are interested, let me know.

One thing I would like to make in the future is a 6502 CPU board that is 100% compatible with the original Altair. This would allow a modified version of the Wozniak Apple 1 monitor to run on the Altair. If you prototyped your S-100 card in an Altair you would help accelerate me to that goal.

I would probably have a 6502 CPU chip, buffer chips, and a spot for a medium sized FLASH chip AND a 1702. The woz monitor would be
modified to use the 2SIO.

There IS a version of "CP/M" for the 6502. It would also be neat to run that!

Too many ideas and not enough time!

This is the prototype that I would be interested in getting rid of...

[sje]

It's Freescale that owns the 68000 IP, and they don't make DIPs of any kind. Old 68000 DIPs can be had, possibly salvaged from old Macs, Amigas, etc., for about US$20 each.

Anyway, a 68000 really needs a 68551 MMU to do Linux, and even that's a little clunky. I wouldn't try it with less than a 68030 as the base chip, and that was never made in DIP form.

[sje]

The S-100 bus had too many problems physically, electronically, and logically. That's why it died out so quickly. Designed for the 8080, and not very well at that, it is a piling of kludge upon kludge to make the S-100 bus work for a 6502, 65856, or 68000.

[Grant Stockly]

Originally Posted by sje

The S-100 bus had too many problems physically, electronically, and logically. That's why it died out so quickly. Designed for the 8080, and not very well at that, it is a piling of kludge upon kludge to make the S-100 bus work for a 6502, 65856, or 68000.

Its already enough of a stretch to throw a 68000 on an S-100 card and say "Altair runs Linux". It has to at least get power from the S-100 bus and make the lights blink!

Imagine it, with Linux the Altair would finally be Slashdot worthy.

[Grant Stockly]

Originally Posted by sje

It's Freescale that owns the 68000 IP, and they don't make DIPs of any kind. Old 68000 DIPs can be had, possibly salvaged from old Macs, Amigas, etc., for about US$20 each.

Anyway, a 68000 really needs a 68551 MMU to do Linux, and even that's a little clunky. I wouldn't try it with less than a 68030 as the base chip, and that was never made in DIP form.

For uCLinux you wouldn't need an MMU. That means its just an application host and not a development environment, but could still be fun. Possibly more useful than an 8080???

PLCC versions of the 68LC000 are available from DigiKey, and they are 100% compatible with the old Macintoshes. I even built a carrier board and ran a Macintosh on one.

The DIP versions are available from second source places like Unicorn.

http://www.unicornelectronics.com/IC/68000.html

I buy ALL of the ICs for my kits from Unicorn.

I would rather buy an old DIP 68000 than a new PLCC 68LC000...because a 68 pin DIP is just TOO cool...

[sje]

Originally Posted by Grant Stockly

I know of at least one case where uCLinux has run on a 68000, but the FPGA company who built it for their core doesn't want to share the kernel patches.

Failure to share in this case is very likely illegal due to GPL conditions.