exxos's Atari, Amiga & retro forum

Cpuspeed works now, although there still seem to be a few glitches (see screenshot). This doesn't always occur, only occasionally. Also the upper limit seems to be fixed at 79 mhz, not sure if this is intentional?

I was able to run AmigaAMP and play some mp3s. HOWEVER, even the non-fpu version crashes (and that includes the 68000 executable...). It shouldn't happen, but it does. I installed the non-fpu version of the mpega.library yet these FPU calls keep happening.

In order to run AmigaAMP and play some files, you need to use the Non-FPU version AND run FEMU.040 (the very basic software FPU emulator).

So yeah... it seems that femu is essential on an LC060 system. Onwards.

alenppc wrote: 27 Aug 2020 15:19 I installed the non-fpu version of the mpega.library yet these FPU calls keep happening.

Scratch that. The bug is in the mpega.library. Even the non-fpu version does FPU calls. Installed the basic 020 version and now it runs. Holy crap. This is gotta be the worst flaw in AmigaOS to date.

alenppc wrote: 27 Aug 2020 15:19 Cpuspeed works now, although there still seem to be a few glitches (see screenshot). This doesn't always occur, only occasionally. Also the upper limit seems to be fixed at 79 mhz, not sure if this is intentional

the next jumper step after 79 is 100.

OK, that's fine then. It seems I got most of the things running. The trick that everyone needs to remember is to install 020 executables only. None of the 040 or 060 stuff will work, even when it states non-FPU. I think the compilers are crap.

I am getting the hang of this now. DoomAttack 68040 runs insanely fast on LC060 (with the 040 c2p routine). The 060 version predictably crashes.

EDIT: I can run most PC ports. Heretic and Hexen are playable but I recommend setting the CPU speed to 75 mhz. Descent runs but crashes after a while. It's a known bad port though.

Update: ScummVM rocking it on LC060. Need to use the 030 executable (novacoder's port), but at 80 Mhz it seems to run pretty fast.

040 and 060 versions crash.

So would it be right to say, the user simply goes with the 020/030 versions and most software will run, and run fast!?

matt020 wrote: 31 Aug 2020 00:29 So would it be right to say, the user simply goes with the 020/030 versions and most software will run, and run fast!?

Yes. But there are lots of misconceptions in the Amiga community about the LC060 cpu with people claiming that nothing will run, which does seem apparent at first, but one has to change one’s mentality and consider this as a very fast 030. So I am documenting here the stuff that does run and which version.

FYI The only reason any Doom port would need an FPU is because it lacks the 030’s 32x32->64bit integer multiplication and the author is instead using the FPU to perform this in floating point and convert back to fixed point right after.
I can probably produce an 060 optimized version that is not using the FPU.
As for ScummVM, there should not be any FP calculations in there. Why it would need an FPU is a complete mystery to me.

pipper wrote: 31 Aug 2020 05:12 FYI The only reason any Doom port would need an FPU is because it lacks the 030’s 32x32->64bit integer multiplication and the author is instead using the FPU to perform this in floating point and convert back to fixed point right after.
I can probably produce an 060 optimized version that is not using the FPU.
As for ScummVM, there should not be any FP calculations in there. Why it would need an FPU is a complete mystery to me.

I think Novacoder's dev environment was setup assuming FPU.