X68000 Expert w/26 pin SCSI motherboard connector

[EmpireStateHuman]

I bought what seems to be an X68000 Expert in a X68030 case a while back, and have successfully installed a PicoPSU and created a (v3) boot disk - so far so good. It came without a hard drive installed, but with a hard drive cable in place.

The problem I'm having is that I can't get the machine to recognize either a ZuluSCSI or BlueSCSI card:

- The SCSI cards are powered from the Pico PSU connector when either are plugged in, and flash at boot. They also appear to be correctly starting with their config files (setting x68000 mode) recognized

- I'm using the v3 drive images from https://nfggames.com/forum2/index.php?topic=7231.0

- I've checked with a multimeter, and the SCSI cable buzzes out correctly

On the assumption that this is an Expert and therefore a SASI device, I've installed the SxSI bootloader - but the machine starts up and refuses to recognize the drive.

One thing I've just realized - having checked the cable, both it and the board connector have 26 pins - which make it a *SCSI* cable, not a SASI. I'm wondering if this is really an Expert, although I don't seem to have an option to set a SCSI boot option  in SWITCH.X, and the machine otherwise seems to be working (ie the boards appear to be matched). Can anyone help?

[EmpireStateHuman]

Uh, so it appears from https://x68.aikotoba.jp/xvi/index.html that I have an *XVI* board in the bottom of the machine to go with the Expert mainboard.

I'm a bit surprised this combo works at all, but I guess the SCSI interface is there - is there any way to get a hard drive working without an extra SCSI card, though? Thanks!

[EmpireStateHuman]

Bumping this after I started poking at the machine again: has anyone successfully mixed and matched an X68000 mainboard (that shipped with SASI) with a SCSI peripheral card? I've tried new ROMs (the 1.1 XVI ROM, and a custom ROM built with XEiJ) and SCSI is not recognized.

[aotta]

Bumping this after I started poking at the machine again: has anyone successfully mixed and matched an X68000 mainboard (that shipped with SASI) with a SCSI peripheral card? I've tried new ROMs (the 1.1 XVI ROM, and a custom ROM built with XEiJ) and SCSI is not recognized.

yes, i did in all my SASI machines with BlueScsi2, but other SASI users repored working also with other SCSI emulator, just search the forum!
And, i also did an adapter because the modded SCSI cable is the trickiest part of the job, i made a couple myself but it's a pain, so a specif board helped me a lot: https://nfggames.com/forum2/index.php?topic=7445.0
edit:
re-reading your post, i realized that probably you asked if some other users have an hybrid X68000 (SASI MB with SCSI peripheral board), in that case, i'll be really surprised if you won't be the only one....

[EmpireStateHuman]

Yes - it's a SASI MB with a SCSI peripheral board in an 030 Ace case!

I think the closest machine in spec is actually the Super, so I might try creating ROMs for that machine - or else I need a separate SCSI card. I did check with a scope and the Fujitsu SCSI chip doesn't have its chip select driven, although the floppies work fine. It's funny the PCB - PCB connector is otherwise compatible, though...

[EmpireStateHuman]

I'll stop replying to myself after this, but it looks like the Expert and Super have very similar motherboards - with the exception that the option ROM sockets are 512Kb on the former and 1Mb on the latter, even though the built-in ROMs are 4Mb for both. This matters as I can't directly install 256KB EPROMs with the SCSI driver, as the A16 line doesn't appear to be connected.

TL;DR: if anyone has the Expert or Super schematics, I would be *very* grateful. Thanks!

[EmpireStateHuman]

Finally: this is possible, and someone beat me to it: https://www.katch.ne.jp/~x680x0_mania/aceper.html. TL:DR is to wire the A16 pin from the EPROM to pin 81 of the OHM chip. It works!

[incrediblehark]

Congrats on getting it to work! Also I like the "X68000 ACEPER" model name in that linked post