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Sorry to briefly hijack this interesting thread, but in this respect, Apple would have been merely catching up with Psion, which had support for RAM, ROM, EPROM and Flash cards up to 512kB in their MC ultra-portables in 1989. The Psion MC400 was a ground-breaking laptop design, much smaller...

I didn't know that! LC II can also boot System 6.0.8! Not so different to the Q630 then! This has been noted. @Phipli was correct to point out the MMU. This was my main criteria when buying my first Mac, my LC II (Performa 400 actually). I didn't want the software I was running to be dependent...

Ironically it was very under-utilised. Most workstation manufacturers moved onto RISC around the time of the ‘030 and Sun preferred the ‘020 with their own MMU design.

Ok, so it all sounds v ambitious! The 68030 has a 256b data cache which can speed up some data processing.

Quick question. If you're emulating an LC, then you must be emulating a 68020. Why choose that rather than a 68030? Then you get an MMU & can emulate an LCII, which I believe is the same thing, except for the CPU.

Thanks for the superb explanation! This will sound dumb, but is it possible to modify the 539x so that it is aware the host (i.e. the emulated host) wants to read (or write) 4 bytes and therefore can't block an instruction half-way? e.g. by creating an additional 2 byte holding buffer? I'm sure...

Hi @Arbee , Thanks for this! So, in theory we could guess that PrimeTime II is IOSB and see how far we get? And if we know PrimeTime II is a respin of IOSB, does that mean there's some effective documentation after all? <Mindblown>. This doesn't make sense to me (yet). The SCSI bus isn't part...

OK, turns out I can play this in Safari :-) ! I didn't know it had .ogg support! It occurred to me that a standard Amiga 500 contains 100% Chip RAM, which I understand means there's contention between the video chip (Paula?/Agnes?) and the CPU. So, that 7.09MHz Amiga has a slower effective CPU...

So, what you're saying is that Performa x200 emulation isn't ready for PrimeTime :ROFLMAO: ! The best information I had was the developer note, which doesn't really give a lot away. Looking at the architecture diagram, F108 and Primetime II are most of what constitutes the Px200s including...

Cool, nice to see a 603 'Mac' and 603ev being emulated. I guess they'll get onto infinite Mac at some point. Does 5200/6200 emulation work given that Valkyrie is emulated? I had a look in the machine list, but couldn't see it. In theory is it simply a question of adding the right machine...

Hi @Phipli ! My next mini-project is to remove the existing Flash PLCC using the SMD Rework Station/Hot air thing (when confident enough). I will dump the flash contents (@joevt ). What's the literal sequence of steps to solder your replacement? e.g. at the level of: Clean all the pads using...

Ho, ho, you might think so, but actually the other byte controls the motor speed for the floppy drive (of course!). In fact both bytes are PWM outputs: the sampled audio stream is just a poor-soul's PWM. Yes, that's what you'd do! It'll be a bit slower than the previous routines, at 12c/sample...

Latest update: @Phipli very kindly provided me with another 192MB of RAM on a 128MB and 64MB pair of sticks. I already had 3 DIMMs used (64MB*2+32MB), so I removed the 32MB and added the other 2. I also used one of his 2mm jumpers to replace my hacky use of the original jumper block. However...

Close. The actual code snippet did it the other way around: move.l (a0)+,d0 movep.l d0,0(a1) It moved 4 bytes from an 8-bit mixing buffer to 4 consecutive alternate bytes in the hardware audio buffer. You can't use the (an)+ addressing mode, because only disp(an) is supported for...

I see you started contributing from near the beginning, there are quite a few posts which discuss optimising basic playback performance. I'm not sure exactly how familiar you are with Mac audio and all the posts in this thread. So at the risk of condescension, I guess you know that a compact...

Original 68K Macs up to a Mac Plus, have about 6.5MHz of effective performance, because the video hardware fetches a word every 8 cycles when copying the actual frame buffer. Thus 4*(512/16)*342*60.15=2633126.4 are taken/ second. In theory, this leaves only 4866873.6cycles /second, but obviously...

e.g: Works, although it's a little clumsy.

I guess you could use the C pre-processor? Define the block of code in a macro, then define a rept macro to repeat another macro a number of times with some kind of recursive #ifdef trickery? Finally, have a AsmRept(n, macroName) in the asm block? @8bitbubsy , [ @joevt ], if you're familiar...