exxos's Atari, Amiga & retro forum

czietz wrote: 13 Apr 2022 11:17 Here you go. Test program runs "MOVE SR,Dx" in user mode and tests whether this is a privileged instruction. It isn't on the 68000 and it should not be on the 68SEC000, either.

:thanksyellow:


Will report back once tested out. Finally see what's what then.

czietz wrote: 13 Apr 2022 11:17 Here you go. Test program runs "MOVE SR,Dx" in user mode and tests whether this is a privileged instruction. It isn't on the 68000 and it should not be on the 68SEC000, either.

I just gave it a try but the text vanishes to fast to read its result.

Run it from a command line such as EmuCON.

@czietz

MOVE from SR is NOT privileged

exxos wrote: 18 Apr 2022 17:47

MOVE from SR is NOT privileged

So, it's the same as on the plain 68000. Therefore, the Wikipedia article and the 68k PRM are wrong regarding the 68SEC000 and this instruction, as @ijor and I already had suspected.

czietz wrote: 18 Apr 2022 17:58 So, it's the same as on the plain 68000. Therefore, the Wikipedia article and the 68k PRM are wrong regarding the 68SEC000 and this instruction, as @ijor and I already had suspected.

:bravo: :thanksyellow:

Nice. But please note this still doesn't mean that is 100% compatible with a "regular" 68000. But in the worst case it might have some minor issues that should probably affect only some protections.

ijor wrote: 18 Apr 2022 23:53 Nice. But please note this still doesn't mean that is 100% compatible with a "regular" 68000. But in the worst case it might have some minor issues that should probably affect only some protections.

True. If you can suggest some to try I can run the CPU at 8mhz when I get chance. I would imagine faster CPU speeds will inherently break some stuff anyway.

The CPU isn't 100% emulating the 68000 anyway. I push the ACIA chips to the max. I assume running E-clock faster wouldn't break stuff but I don't know about timing sensitive stuff anyway. Bus grant works slightly diffently as well.

exxos wrote: 19 Apr 2022 00:05 The CPU isn't 100% emulating the 68000 anyway. I push the ACIA chips to the max. I assume running E-clock faster wouldn't break stuff but I don't know about timing sensitive stuff anyway. Bus grant works slightly diffently as well.

Could your acclerated ACIAs be exacerbating your soft reboot problems in EmuTOS, incidentally? Or was that on the 536?

BW

Badwolf wrote: 19 Apr 2022 12:27 Could your accelerated ACIAs be exacerbating your soft reboot problems in EmuTOS, incidentally? Or was that on the 536?

I've lost track whats what. The SEC booster was only resetting AFAIK when running 64MHz due to bus loading. It would run fine on 50MHz. The ACIA's are rated up to 2Mhz anyway, so they are not being " overclocked" as such. But obviously they are not being clocked at 500KHz either.