in case you are interested to test new fpga accelerators for a600/a500

[Plaz]

Last I read was that some instructions were incompatible on the Coldfire that could not be trapped so the code basically has to be run under (JIT) emulation.

Back in the day I worked on one of the coldfire projects specifically on code compatibility issues.

The exact problem is that there are matching instructions which are completely legal on both coldfile and 68K... BUT they execute different functions. Since these codes are legal, there is no way to trap them in supervisor mode. The 68K code is accepted by the coldfire, but doesn't do what's expected by the OS. (crash)

To catch these few trouble codes (2 if I recall) some other method is needed. Pre-processor one possibility. In the end, any of the solutions greatly increased the complexity and cost of a coldfile Amiga card.

The Atari cold file was successful mainly because their OS didn't use these 2 matching op codes, so they didn't have to worry about them.

Plaz

[Plaz]

Motorola could have sold a lot more CF processors if they had been smart and allowed all 68k instructions to be trapped

Thanks for the list. I specifically remember #2 and 3. With those "unsolvable" I never progressed far enough to see #1. .

Motorola's decisions confound me too. Seems it wouldn't have taken much to build a better bridge to legacy 68K hardware especially since there was so much of it all over the world.

@Thread

Interesting and contentious, but so far civil. I hope it continues that more progress is made.

Plaz

[Plaz]

For a long time software for Amiga has come released in more than one version. For example... 68000 and 68020 versions. Wouldn't it be possible for developers to continue this practice with an additional release option for Apollo card owners?  Or am I misunderstanding this part of the discussion?

That being said, how would a compiler deal with new features added to Apollo? In the case of 68K vs 020 versions, it was basically a compiler switch option.

And maybe that second question belongs over at the techie Apollo thread.

Plaz