I guess you will get access to the additional drives after installing the ASPI driver and ASPIDISK.SYS driver.

This issue is independend from mainboard bios.

That old Adaptec BIOS will just install drives 80h and 81h and the controller does not care about other drives.

Please install ASPIDISK.SYS and check whether the option in controller's BIOS has an effect.

That is a good point, I haven't tried to load any ASPI drivers yet - was figuring I should see each drive show up during detection by the Adaptec card. I'll load an OS and see what happens. Thank you, that's helpful.

Does SCSI have an order for cabling? Assuming unique SCSI IDs, does it matter that it goes

Controller (ID7) -> SCSI2SD (IDs 0-5) -> CDROM (ID6)

Would it be better to reconfigure to have the SCSI drives as IDs 6 through 1 and make the CDROM ID0 at the end of the chain? Been reading SCSI docs and none are addressing cable order.

No the BOOT drive should be ID0 and CDrom last ID. YesThe motherboard BIOS has nothing to do with the Adaptec BIOS.
The Adaptec should see all the drives, but you are limited to only the first two being bootable or seen from DOS with 154x card until you load the ASPI driver. Also whatever drive is on the end of the cable MUST be terminated (if cdrom then terminate the CDROM).

oops.........you should load Aspi4dos.sys and then Aspidisk.sys in config.sys.
From Adaptec: "Note: The ASPIDISK.SYS driver must be loaded after the ASPI4DOS.SYS or ASPIEDOS.SYS drivers for proper operation. "

What OS are you going to run on the thing? Remember that with FAT16 you will need 20 partitions to use all that space...

jakethompson1 wrote on 2020-06-08, 23:25:

What OS are you going to run on the thing? Remember that with FAT16 you will need 20 partitions to use all that space...

More like 26, including the optical drive and floppy drive (hope you have only one) and 6x4x2GB partitions .

Running a FAT32 capable version of MS-DOS (7.1 or higher) or FreeDOS seems like a good idea indeed .

First of all, thank you for the replies - it was helpful.

The termination was a big win, SCSI2SD functions properly now - but still limited to 2 drives. The detection process for the Adaptec card shows only 2 upon boot. I confirmed in SCSI2SD that it has a total of 6 devices configured and enabled @ 7.8GB each. I'm also not trying to get the full 64GB, just 6 hard drives of 8GB each.

I'm testing with Windows 95, OSR2 C edition. Last published ASPI drivers for Win95, 4.60. I also tried booting to DOS with the DOS ASPI drivers loaded via config.sys and autoexec.bat with the same result.

So just to confirm with someone else who might have more than 2 SCSI HDDs working, you only ever expect to see 2 drives in the initial power-on BIOS test that the Adaptec card runs? Trying to determine if I need to focus troubleshooting there or in Windows/driver-land. Thanks again all.

I cannot duplicate your exact setup but have had 4 or more scsi HD on 1542 and 2940 and other adaptec cards and they all show during boot. Think the difference is that they were real HD's and SCSI2SD creates virtual HD's off one "hd". I know that is not any help but think some of the modern work arounds are just that and not the cure for using the real things. Did the documentation with the SCSI2SD state you could create 6 HD's off one SC and have them workunder DOS or Win9x ? sorry did not look into it since I do not know your exact make/model of a adapter...

If I recall correctly, the 1540 should support drives up to the 137GB mark. Provided you are using the latest firmware. Why you are making different hardware logical drives confuses me.

The 2 drive limit is likely a LUN limitation. ( https://en.wikipedia.org/wiki/Logical_unit_number )

Do yourself a favor and just make the SD card one large drive. THEN you can partition it in dos/windows more to your liking. If I know the scsi2sd device correctly that will allow you to drop that sd card into a new machine easier as well.

Thank you all again for the suggestions - I figured it out.

The SCSI2SD has two power connections, one to the PSU in the computer and a second to a micro-USB connection to a secondary PC (for configuration). When you change the config, the new settings don't "take" until the device is powered off. Just powering off the SCSI computer isn't enough, you *also* have to disconnect the USB cable from the second computer you used to program it. That will cause the card to be fully powered off and re-read your new config.

In my case what that meant is my initial config had 2 drives, but the new config with the 6 drives was being saved to SCSI2SD but not re-read. By accident I pulled the USB cable and re-inserted it and BOOM it came right up with my drives. One other note, all of the drives are seen upon the very first initialization of the SCSI bios when you can hit CTRL-A. If you don't see the drives there, Windows or DOS won't see them either.

And my SCSI card is limited to 8GB per drive so that's what I used (confirmed by the Adaptec documentation). I tried to make a large drive over 8GB but it didn't work.

Thanks everyone, hope this tip helps someone else down the road.

Excellent. Well done.