exxos's Atari, Amiga & retro forum

Sorry if the question is lame, but is it possible to programmatically / with jumpers/ switches disable TF536 and run it as stock m68k without actually pulling it out of the socket?

It does run in stock mode other than when accessing fast-ram ?

Apologies if I'm not being precise here. Is it possible to run it just as m68k, no ram, no ide, no 030.

No. This has been stated a few times before. For a start, even if the 68030 were running at 8MHz it would still have incompatibilities with the 68000.

This is one of the reasons I've been working on a dual CPU board with @derkom's CPU switching circuit so as to have both the TF536 and a 68000 in the machine at the same time and switch between them as required (with a reboot in between).

bartekmalysz wrote: 27 Oct 2020 22:45 Apologies if I'm not being precise here. Is it possible to run it just as m68k, no ram, no ide, no 030.

If you load Kickstart 1.3 that's all you'll get. The fast ram and the IDE will be disabled and the CPU will only run at 7 Mhz. But some software incompatibility will still exist due to the presence of cache and other general differences between the 68000 and 68030.

bartekmalysz wrote: 27 Oct 2020 21:52 Sorry if the question is lame, but is it possible to programmatically / with jumpers/ switches disable TF536 and run it as stock m68k without actually pulling it out of the socket?

The simple answer is no.

If you run code in chip ram it will run at 7mhz but it will always be an 030 processor not stock m68k. So many things will break because of that.

You can close CDIS and MMUDIS and run OS 1.3. This will give you a 030 with no fastram and no cache running at 7mhz. But you cannot avoid the 030 instructions.

Being able to switch between these modes is a massive extra complexity that adds cost that i simply did not want to pass on to users.

EDIT: In short if you want the system you have to be compatible with an 030 then you need to fix the software. Or dont use an 030.

Thank you for your answers