DingusPPC: A more accurate PowerPC Mac emulator

[Arbee]

So, it's not DMA'd on the Q630, it's SCSI PIO <facepalm>

The only 68k Macs with DMA SCSI under Mac OS are the Quadra AVs. (IIfx has hardware for it but only A/UX uses it).

 

[croissantking]

I think there was, and all Apple did for the 6200/6300 was redesign the logic board such that it was built in.

Would the upgrade have actually been a 6200 board? (As opposed to a LCPDS 601 card)

A clue to this, I believe, is that the 630 and 6200 logic boards are interchangeable and will run in each other's chassis. I'm not sure if the 6300 LB would run properly in an unmodified 630 or 6200 chassis, but the later ones (6360, 6400, etc) almost certainly won't run properly without chassis mods.

The only issue with running 6360/6400/6500 etc boards in a 630 chassis is the lack of 3.3V from the PSU. A 6300 or 6320 board would drop into a 630/6200 with no problem.

 

[CC_333]

Would the upgrade have actually been a 6200 board? (As opposed to a LCPDS 601 card)

I'm not sure.

If not, what does a PPC upgrade for a 630 look like?

The only issue with running 6360/6400/6500 etc boards in a 630 chassis is the lack of 3.3V from the PSU. A 6300 or 6320 board would drop into a 630/6200 with no problem.

I see. I thought it was something along those lines, but I couldn't remember for sure (my knowledge is a bit rusty from having been on the sidelines for the better part of a decade (2019-ish to now-ish)).

c

 

[croissantking]

I'm not sure.

If not, what does a PPC upgrade for a 630 look like?

Question for the hive mind then, is there one?

 

[CC_333]

Question for the hive mind then, is there one?

Indeed.

A quick search uncovered this LEM article (take it with appropriately-sized gain of salt): https://lowendmac.com/2016/powerpc-601-cpu-upgrades-for-68040-macs-with-lc-pds/

If the article is correct (why wouldn't it be?), there apparently was an Apple Power Mac Processor Upgrade (APMPU for short) made by DayStar and featuring initially a 66 MHz PPC 601. DayStar also marketed the upgrade directly as the PowerCard 601, and later also released a 100 MHz version of it.

When DayStar went under, Sonnet took over the design and sold it as the Presto PPC.

Hopefully someone can confirm all this.

c

 

[Snial]

<snip> Apple Power Mac Processor Upgrade (APMPU for short) made by DayStar and featuring initially a 66 MHz PPC 601. <snip>

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

 

[CC_333]

What's a GD emulator?

I'm pretty sure the 4 MB ROM is necessary for it to work, so it must have been included?

c

 

[croissantking]

What's a GD emulator?

I'm pretty sure the 4 MB ROM is necessary for it to work, so it must have been included?

c

Gary Davidian - the guy who wrote the 68k emulator

 

[Snial]

What's a GD emulator?

Cr CroissantKing’s reply.

I'm pretty sure the 4 MB ROM is necessary for it to work, so it must have been included?

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 in the right location, then jump to the right place in the PPC Rom, it’ll reboot and we’re in PPC mode.

I should clarify, I suspect these upgrade cards do actually have whole 4MB ROMs.