DingusPPC: A more accurate PowerPC Mac emulator

[kataetheweirdo]

This emulator has been discussed in the Infinite Mac topic already, but I figured it deserves its own topic.

I've been working on this emulator for some time with a few other people. It's far from complete, but it's being actively developed.

DingusPPC's source code repository is here.

Releases for the emulator can be downloaded here.

 

[joevt]

DingusPPC's source code repository is here.

The wiki page has a link to the Discord server where you can get help for using or developing DingusPPC.

 

[akator70]

Thank you for the work on this emulator. I’m very impressed with the progress and compatibility.

 

[Andrew-R]

I tried to add few lines into help output and README. (attached)

Still not quite work for my case (booting self-created cd with yaboot/Linux)

Bootable ppc cdrom

Yes, thank you, with imac.zip rom from MAME emulation starts, but stuck lately when Linux kernel is loaded?

forums.macrumors.com

 

[kataetheweirdo]

We've got some fixes in for the decrementer. That said, there seems to be some interrupt issues in general and they're not easy to trace.

 

[kataetheweirdo]

Recent updates have fixed Apple Pippin emulation. BeOS can also boot up now, albeit somewhat slowly. Performa 6400 emulation is also being worked on.

 

[Snial]

Recent updates have fixed Apple Pippin emulation. BeOS can also boot up now, albeit somewhat slowly. Performa 6400 emulation is also being worked on.

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 description, e.g. machinecrusader.cpp whose contents reference the correct peripherals?

dingusppc/machines at master · dingusdev/dingusppc

An experimental emulator. Contribute to dingusdev/dingusppc development by creating an account on GitHub.

github.com

It's listed as a project, but there's no content.

Adding additional machines • dingusdev

Adding additional machines

github.com

 

[joevt]

In theory is it simply a question of adding the right machine description, e.g. machinecrusader.cpp whose contents reference the correct peripherals?

Yes. But there may be hidden things missing from the emulation such as Board ID registers. Schematics and memory dumps, etc. may show these hidden things.

 

[kataetheweirdo]

The major things that are missing for the Performa 5200/6200 emulation are the F108 memory controller and PrimeTime II I/O controller.

We haven't found any documentation for these yet, nor has code been found.

 

[Snial]

Yes. But there may be hidden things missing from the emulation such as Board ID registers. Schematics and memory dumps, etc. may show these hidden things.

The major things that are missing for the Performa 5200/6200 emulation are the F108 memory controller and PrimeTime II I/O controller.

So, what you're saying is that Performa x200 emulation isn't ready for PrimeTime !

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 SCC, SCSI, IDE, SWIM II, VIAs, sound controller etc.

I also note that the Taylor Design website appears to be down, so one can't get the developer notes from there. However, a copy is at PeterHuman.net.

Index of /library

I realise this doesn't help. Maybe there's still some P5200 developers around somewhere who have documentation squirrelled away.

 

[CC_333]

Somewhat off topic, but fun: last I checked, preterhuman.net still had a hotline server with tons of goodies in it.

c

 

[Arbee]

The major things that are missing for the Performa 5200/6200 emulation are the F108 memory controller and PrimeTime II I/O controller.

We haven't found any documentation for these yet, nor has code been found.

PrimeTime and PrimeTime II are essentially re-spins of IOSB. The fun part of all of those chipsets is that they expect to be able to halt processor bus read/write bus transactions indefinitely while the SCSI bus catches up. That's a serious pain for emulation, although it's probably a lot simpler on PPC where there aren't the side effects of MOVE.L (A1)+, (A2)+ to deal with when you need to rewind.

 

[Snial]

Hi @Arbee ,

Thanks for this!

PrimeTime and PrimeTime II are essentially re-spins of IOSB.

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?

The fun part of all of those chipsets is that they expect to be able to halt processor bus read/write bus transactions indefinitely while the SCSI bus catches up.

<Mindblown>. This doesn't make sense to me (yet). The SCSI bus isn't part of the main bus, so in what sense is it catching up? In my mind, SCSI is DMA-driven (or effectively, since the SCSI chip can transfer data without CPU intervention). So, data transfer is inevitably asynchronous: the SCSI chip sends a command (or series of commands) to the SCSI device and then the SCSI device sends its bytes (e.g. the bytes from a sector) to the SCSI chip which then generates bus transactions to send data to the target memory locations.

Then to me, SCSI doesn't need to 'catch up', since it's always way behind and because data transfers from the device to the SCSI chip can take a wide span of time depending on e.g. seek times or the speed of the drive, then the SCSI chip will perform data transfers as and when data is available.

That's a serious pain for emulation, although it's probably a lot simpler on PPC where there aren't the side effects of MOVE.L (A1)+, (A2)+ to deal with when you need to rewind.

I'm sure that's true, no idea how MOVE.L (a1)+,(a2)+ could interfere with a SCSI data transfer.

Looking forward to a bit of education!