PEx/PowerMac 9700 EVTA logic board observations.

[Trash80toHP_Mini]

Haven't seen much of this information documented online. Marchintosh project was restarting my bare board PEx in Netrat 1125 4U TeleCom Server casement project. So took a careful look at its 9500 stand in/donor case bits and the specs for the 9600. This is what I found:

Technical observations:

Loving the lack of onboard video on the 9500 with that knockout to cover the port for it. Makes it just perfect for this Batch A EVTA PEx/PowerMac6700 ProtoBoard which lacks the onboard video subsystem components. Wondering if they'd intended to use that godforsaken 9500 crumblecase for the 9600 given that knockout? Didn't pan out as the beefier PSU required would have protruded an inch or two out the side. It all fit in the bare bones inner case of my 9500 testbed.

Gotta fab a "knockout" for the AAIU port opening though. They dropped AAUI from 9500/9600, going straight up RJ-45 only at long last!

Idiots at the Infinite Loopiness should also have dropped the long obsolete DA-15 video connector and gone straight up HD-15 VGA.
But noooooo! Didn't do that for Beige G3 either. So it goes . . .

PEx FINALLY moved from Fast/Narrow secondary internal only SCSI bus to UltraSCSI, both inside and out! Connector's different and may need a tad more clearance for the cable retaining "earclip" on the side next to the defunct AAUI hole in my 9500 donor's backplane cover plate. Looking forward to seeing what a pair of my 2.5" Savio UltraSCSI server drives will sound like through the filter behind the grated drop-door front of the 4U Netrat case.

Don't recall ever reading about that SCSI upgrade anywhere online, just noticed it. Beige G3 moved to Fast/Wide SCSI via PCI Card, so UltraSCSI would be dependent upon card installed therin?

Two ATA Bus connectors is a nice touch.
_________________________________________________________________________________

Has anyone seen any of this drivel posted anywhere on the web?

 

[joevt]

Thread title says 9700. But your post doesn't say 9700 anywhere. It mentions these: 6700, 9500, 9600. I wonder if some of those are mistyped.
6700 is a pizza box form factor of the 9700? Or is that a form factor you are choosing for your PEx case design?

Does your PEx boot? Which ROMs are you using (size, md5, etc.)? I don't think I've grasped how ROMs work in the Power Express machines because there has been some conflicting info and bad ROM dumps. What do the ROMs physically look like? What do they look like when installed in the motherboard? What does the ROM look like from Open Firmware (dump the 4 MiB or however big it is to serial port). Power Mac ROMs have 14 checksums:
https://68kmla.org/bb/threads/pex-rom-project.23568/post-573923

Other info that may be interesting or useful:
dump-device-tree
lspci for Open Firmware (to capture PCI device info such as SCSI cards)
https://forums.macrumors.com/thread...l-work-in-a-beige-power-macintosh-g3.2303689/

Might be interesting to add emulation for this machine in DingusPPC since it is similar to other machines.

Apple Network Server uses PCI cards for its fast/wide SCSI.
I think the PEx ROM includes drivers for that SCSI card, similar to some of the ANS ROMs.
https://tinkerdifferent.com/threads/apple-network-server-macos-based-roms-found.4756/post-42303
That thread also shows how to use lspci for Open Firmware.

 

[Trash80toHP_Mini]

Title could be PowerExpress/PowerMac 9700 They're the same thing, Maybe PowerExpress was the code name? PEx is the abbreviation.
It's a Batch A EVTA PEx/PowerMac 9700 Evaluation Prototype Board, all I have is the board.

Once @trag sorted out the ROM mapping and made ROM cards for myself and a Brit, all booted up nicely, no problems at all!

 

[trag]

Apple Network Server uses PCI cards for its fast/wide SCSI.

The ANS has two 53C825 Fast & Wide SCSI chips on the motherboard. They occupy two of the PCI addresses.

It can also use PCI SCSI cards, of course, although which might have drivers would be interesting. I think there's also some kind of RAID card based on an IBM build available.