Recent content by Snial

Hi @zefrenchtoon ! OK. I don't know, it was the original Tom Tom 8GB SD card from my Renault Zoe, which I repurposed when I had map update on a new card. I have done that now, I used DiskJockey to create a blank 20MB hda image. I've tried USB power and Berg power. Sorry, I just formatted it...

Minor update. I found a sliver of solder on the Berg connector between 5V and GND, which potentially could have caused a problem, so I fixed that. It didn't make any difference. I had buzzed out those connections and hadn't seen a short before. I've found that plugging in the BlueSCSI without...

Summary: I bought a BlueSCSI kit; I've detailed my construction tests here and where I'm stuck due to an error message, advice welcome! I've recently bought a BlueSCSI desktop kit, so I needed to solder the SCSI connector, Berg power plug and other headers. My soldering looks OK to me. After...

I had heard of pseudo-DMA, but I didn't know how it worked. I was just going by @Arbee 's post earlier in this thread: https://68kmla.org/bb/threads/dingusppc-a-more-accurate-powerpc-mac-emulator.51537/post-591881 Here, he explains that on the Quadra 630/Performa 630, which is essentially the...

Cr CroissantKing’s reply. Not necessarily. If the system boots from 68K, it’ll check for a PPC ROM, but it could be a minimal ROM. Then you could load the PPC ROM from disk, like a NewWorld Mac does, because you already have a CPU that can do that. Then juggle the (PPC) MMU tables so the ROM is...

Hmmm. I guess the card came with a full GD emulator, 4MB PPC ROM?

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...