Retro 68000 computer designs

Are there any retro 68000 single board computers out there with
512kb ram/rom,rs232 serial i/o and dual compact flash cards?

There are many in various guises:

Some examples:

that’s SD card though. Another:

Also SD.

Searching with the popular search engines brings up:

and many, many others. Just use google or duckduckgo, etc.

-Gordon

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This one looks promising (68K nano), but it still needs hacking on the schematic for 2 CF cards. This way I can backup the system.

Backup - in hobby retro systems…

It’s an interesting point, but I really feel the requirements of 2 devices (be they physical drives, CF, SD cards, SSD, whatever) is overkill for a small hobby project.

Especially if you use a common file format on the device - e.g. FAT or one of its variants.

Or just use serial with xyz modem, kermit, etc.

FWIW: When I started my own retro system I designed a filing system for it - although it ended up being a somewhat modified version of something based on the Apple ProDOS documentation… And subsequently regretted wasting all the time on it. I did have serial file transfer but while usable not as convenient as pulling the SD card and sticking it in a PC to do bulk file copy.

I had fully intended to write a file system module for my Linux desktop to run under FUSE, but that never happened, so one day I just bit the bullet and re did the while thing using FAT. I’ve not regretted it. Lifes too short.

-Gordon

And subsequently regretted wasting all the time on it. I did have serial file transfer but while usable not as convenient as pulling the SD card and sticking it in a PC to do bulk file copy.

I tend to look at computers from the programing side, makiing backups
and duplicating floppies are important as well as ease of programming.
I need a stable 16/32 bit hardware platform and I don’t want to reinvent the
wheel again. Self hosting and stand alone are important to meI don’t want to spend time revising PCB layouts, just to get a working machine.
Most designs seem to be “Penny wise, pound foolish”.

I am not fond of the 68000 but what other real ( as in for sale) 32 bit chips are out there to build with. Load/store cpu’s are too complex hardware and software wise for a DIY project.

Not really sure what to suggest here … I know you’ve gone through the loop(s) of making your own CPU, etc. various bit widths too, but making backups and duplicating, etc. I see that more as “operations” than programming. If you want a retro backup system, then tape might be where it’s at.

Self hosting - well, Fuzix has been around, also One Man Unix and a few others - I’ve pointed out OS-6 (In BCPL for the 16-bit Modular 1) My own RubyOS:BCPL took inspiration from that.

I started with real CPUs - the 65C02 then the 65C816. I did (and still do) want to make my own CPU but it’s a bit beyond my means right now, however I have identified a platform that may make it easy to at least make a virtual version of it - The PiTubeDirect system on the old BBC Micro - a combination of the very new with a “properly” old/retro system of the 1980s.

I’ve been through this loop too, and posted about it in a few places. The 68K is still there - new, hobby friendly in leaded SMT packages in the form of the ColdFire CPUs. But NOS originals are still available too - as demonstrated by the multitude of 68K systems available now.

For me - after the 6502 (or 816) what was there? (Other than 68K and Intel) - very little. The TMS9900 which seemed a little limiting to me. The Inmos Transputer (expensive on the 2nd hand market), NS32016 or …

I went for RISC in the form of RISC-V - while relatively new has its roots in the original Berkley RISC of the early 80s and I’d used Sparc and i860 RISC systems in the past so the concepts were easy to grasp… It turns out that I couldn’t (still can’t) get a nice hobby friendly 32bit system with 512KB to 1MB of RAM but I did emulate it and get my OS running on it and ran it on limited, but real hardware. (The closest I’ve found is the ESP32-C3 and now C6 systems)

After that - ARM. I was resisting ARM for many reasons, but ARM it currently is. Sort of as that’s what the PiTubeDirect project is and I already had a bare-metal framework for a popular ARM system - the Raspberry Pi (Original version 1B). In theory I can get the PiTube to emulate the virtual CPU my system needs and make it look like a real CPU to the BBC Micro host computer. One day.

But there is the same issue with ARM as RISC-V - hard to get small systems with just 1MB of RAM unless I get an original Acorn Archimedes system - As with RISC-V, it’s either modern microcontroller variants with typically KB of RAM or multi-core GB systems designed to run Linux.

Everything really did change mid-late 80s.

I think you have to be realistic with your own ideas - carry on with your own CPUs and so on or adopt a relatively “period authentic” system and work on the software.

An intermediate stage might be FPGA. This was a route I looked at for my RISC-V solution. Small board, existing RISC-V core and subsystem I could put inside the FPGA with a couple of MB of RAM and (in theory) off I go… It wasn’t that easy, but a few things changed when I was looking at it some time back. Maybe I ought to revisit it…

However I lucked out in that when I ported my OS to RISC-V then ARM, I could just run the original binaries. They just went faster. All I had to write was the bytecode interpreter again (and again - it gets easier every time)

-Gordon

There are industrial 68040 VME boards still available, though probably so spendy I’m afraid even to look: CM Computer | CM-CPU-40/60

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A few more options to consider:
https://retrobrewcomputers.org/doku.php?id=boards:sbc:tiny68k
https://retrobrewcomputers.org/doku.php?id=builderpages:plasmo:t68krc_r01

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Net was down, so I am looking at that now.
Can one get OS/9 (68000) for this instead of CP/M?
Ben.

Interesting query. It is very difficult to find someone who know what it is OS-9 (68000), and know how to use it… most users are using OS-9 for COCO = NitrOS-9

Whether this link would help?

and also post here: DangerRuss Things: Resurrecting the OS-9/68K (OSK) kernel using the FAME 68K Emulator

OS-9 works or should work on ROSCO board… but no official ports are available…
I am interested in learning OS-9…

I picked up the ROSCO board, and plan to use it to emulate some of my design ideas. I also ordered a National 32016 cpu for later development.
Ben.
PS: I hope the Royal Mail package does not get lost coming to Canada.