68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.

Classic MacOS on a homebrew 68k board

Posted by: chiggen on 2024-08-20 16:16:55

Would it be possible to run classic MacOS on a homebrew 68k board similar to the 68k-nano? How hard would it be if it's possible?

Posted by: Nixontheknight on 2024-08-20 17:01:18

You would have to match the limitations of any given Macintosh exactly

Posted by: chiggen on 2024-08-21 05:43:48

Cool. Thanks for replying

Posted by: cheesestraws on 2024-08-21 06:05:36

It would be hard but not impossible - you would have to either, as @Nixontheknight says, accurately recreate a specific Mac model, or you would have to write a lot of low-level software.

The latter option is kind of like doing "Basilisk II but in hardware" - you would have to make your hardware look enough like a specific Mac to get through early boot, then introduce new drivers - I'd probably try to do this myself by creating a declrom in a fake card slot. Those drivers can then do things like block storage and displays in ways that aren't the way the original Mac did it. This general approach is how things like the Outbound Laptop did it on non-Apple hardware back in the day.

But you'll be fighting the OS all the way to do it and it will be a big project - and a certain amount of the documentation for this appears to be lost. If you're trying to bring *up* the board, I'd probably look at something like EmuTOS or if you want something retro, GEMDOS. The full source code is actually legtimitately out there for both of those (the SuperMario code leak is not complete) and they're significantly simpler operating systems.

Posted by: Arbee on 2024-08-21 10:11:32

Much like with a software emulator, the major hang-up would be reproducing the IWM since that's the only true custom chip on the 128/512/Plus. (Or you could take one from a battery bombed board).

Posted by: Snial on 2024-08-21 13:05:05

Cool. Thanks for replying

It's a bit disheartening when it feels like you've had a good idea, but it turns out to be more challenging than anticipated. Unfortunately, most projects are like that anyway. I was trying to think of a way of getting an MCU to emulate all the I/O, running code that's largely been written for other emulators, but I think it'd be pretty much as challenging as any of the other solutions. However, check out:

RP2350: Raspberry PI PICO-2 with 520kB of RAM

CMake Error at pico_sdk_import.cmake:68 (message): Directory '/Users/julianskidmore/Development/pico/pico-examples-eclipse' does not appear to contain the Raspberry Pi Pico SDK Call Stack (most recent call first): CMakeLists.txt:4 (include) Any Ideas? (please don't just tell me to install...

68kmla.org

And:

MicroMac, a Macintosh for under £5

https://axio.ms//projects/2024/06/16/MicroMac.html Just discovered this, am kind of surprised that no one (including it's creator) has mentioned it here.

68kmla.org

M0Bius is my attempt to write a 68K emulator for a Cortex M0+; I'm making progress!