I'm not as knowledgeable as some others on this site, but I have a few thoughts.

Is there anything stopping you from running DOS 6.22 or 7.x instead of FreeDOS in your A: drive? They can use FAT32, which will handle partitions above 2GB.

If you aren't opposed to using abandonware, maybe booting a GHOST version 6 floppy would work. (Or copy its executable to the IDE Drive. Hopefully you can still use the IDE as the destination)

Also, rather than imaging the drive, perhaps you could use the MS-DOS "XCOPY -e -i" command from the A: drive to clone the contents of the SCSI partition to one on the IDE?

gamdat wrote on 2026-09-12, 00:31:

If there's no way to access the SCSI drive when it's connected to the Fast-SCSI-2 controller using FreeDOS, could I move it to the Adaptec controller? Would I have better luck finding a compatible driver?

Any help appreciated.

Hi,

I don't have Compaq SCSI adapter, but I do have a 4GB drive connected to my Adaptec controller, and it works great.
Also, I am using MS-DOS 7.0 here.

Here are the two line I have on my config.sys:

DEVICEHIGH /L:2,41552 =C:\DRIVERS\SCSI\ASPI7DOS.SYS /D

I have one more line, but it's for my SCSI CD Rom.

Alternatively, you can try one of those SCSI to USB adapters and use a modern computer to take the files out...

Not sure if this will help, but here it is.

Lylat1an wrote on 2026-09-12, 12:30:

Is there anything stopping you from running DOS 6.22 or 7.x instead of FreeDOS in your A: drive?

I guess the main reason I used FreeDOS is because it was the first thing I noticed when I went to look for a free DOS download. It's also open source, actively maintained and contains lots of tools. That doesn't mean it's the best choice... just saying that's why I initially used it.

Actually, I'd really prefer to use Linux, but didn't have much luck finding a simple install that would run on a 486 w/16MB memory. I'm pretty sure it's possible, but will take a bit more work. Getting FreeDOS installed on the drive and working was pretty quick and easy once I figured a few things out.

Lylat1an wrote on 2026-09-12, 12:30:

They can use FAT32, which will handle partitions above 2GB.

FreeDOS can use FAT-32 as well, I just didn't enable it. Please correct me if I'm wrong, but I don't think that's the problem - I don't need a PARTITION > 2GB, I need fdisk to correctly recognise a DISK > 2GB. Those (at least I'm pretty sure) are 2 completely different problems. The problem (I think) is either the Compaq (BIOS) isn't reporting the correct drive parameters to fdisk or fdisk isn't reading the parameters from the BIOS correctly.

Lylat1an wrote on 2026-09-12, 12:30:

Also, rather than imaging the drive, perhaps you could use the MS-DOS "XCOPY -e -i" command from the A: drive to clone the contents of the SCSI partition to one on the IDE?

I want a full disk image (If possible). I'd really like to use the Unix/Linux "dd" command. There's a version for windows, but I haven't found one for DOS.

The SCSI drive contains more than just a single DOS partition... there are 3 partitions: 1) Compaq system config 2) DOS 3) UNKNOWN

I THINK the UNKNOWN partition might be some old version of Unix, but not sure. I was a Unix software engineer 35+ years ago, so it's entirely possible that's what it is.

To be clear.... this is not really a data recovery effort. It's more of a - I wonder if I can do this - effort. This computer has been sitting boxed up in a corner for quite a while.. I bought it new back in 92/93 and just recently re-discovered it while cleaning up that area. When I saw it I went, Hmm... wonder if that thing still runs. Then... Hmm wonder if I could copy those disks. So here we are.

NightShadowPT wrote on 2026-09-12, 14:38:

I don't have Compaq SCSI adapter, but I do have a 4GB drive connected to my Adaptec controller, and it works great.
Also, I am using MS-DOS 7.0 here.

OK. Maybe I'll try that. I was hesitating, just because I wasn't sure if there was something special about the SCSI drive and the Compaq controller combination. The 50-pin ribbon cable runs from the Fast-SCSI-2 controller to the drive and then back to the controller. So I think this means the controller itself is acting as the terminator. The drive has spots for terminator resistor packs, but they're empty and I don't have any 10 pin resistors.

The CD is connected to the Adaptec 2740 with a 50 pin ribbon cable that goes from the controller directly to the CD. The CD drive does have resistor packs, but they are 11 pin, not 10, so I can't just swap them. I do have another 50-pin cable with 5 connectors, so I assume I could connect that like this:

Connector 1 (Adaptec) -> Connector 2 (empty) -> Connector 3 (SCSI drive) -> Connector 4 (empty) -> Connector 5 (CD Drive)

NightShadowPT wrote on 2026-09-12, 14:38:

Alternatively, you can try one of those SCSI to USB adapters and use a modern computer to take the files out...

I'm trying to avoid buying anything. This is mostly a project out of curiosity, just to see if I can do it with the tools at hand.

Lylat1an wrote on 2026-09-12, 12:30:

If you aren't opposed to using abandonware, maybe booting a GHOST version 6 floppy would work. (Or copy its executable to the IDE Drive. Hopefully you can still use the IDE as the destination)

I'm not sure what "GHOST version 6" is... when I search for it, all I see is some kind of publishing site.. I'm assuming that's not what you're talking about.

gamdat wrote on 2026-09-12, 18:41:

Lylat1an wrote on 2026-09-12, 12:30:

If you aren't opposed to using abandonware, maybe booting a GHOST version 6 floppy would work. (Or copy its executable to the IDE Drive. Hopefully you can still use the IDE as the destination)

I'm not sure what "GHOST version 6" is... when I search for it, all I see is some kind of publishing site.. I'm assuming that's not what you're talking about.

Correct, I meant Norton/Symantec's backup software from back in the day. :)

Lylat1an wrote on 2026-09-12, 21:02:

Correct, I meant Norton/Symantec's backup software from back in the day. 😀

Ahh... yes that makes more sense. I found a CD image for Symantec Norton Ghost 6.0, but that appears to be for Windows not DOS. When I tried to run the setup from FreeDOS it says this must be run from Windows. So maybe it doesn't work in FreeDOS or maybe I have the wrong version of Ghost. At any rate, I found an alternate solution more fit to my skill set...

I did a bit more searching for Linux solutions and came across Tom's Root Boot, which I remember using many, many years ago. It's a linux installation that runs from a floppy. I created a floppy image of Tom's Root Boot on the FreeDOS drive while it was mounted on my laptop, moved the drive to the Compaq and booted from it, then wrote the image to a real floppy. Rebooted off the floppy and good 'ol Tom booted right up. As it was booting I noticed it recognized the Adaptec SCSI controller but not the Compaq Fast-SCSI-2.

I switched the SCSI drive to the Adaptec, rebooted via the Tom floppy and it recognized the drive. I then ran the Linux version of fdisk on the FreeDOS IDE drive and it recognized it correctly as a 2.6GB drive. I was able to create a 2.2GB partition on the FreeDOS drive and use dd to create an image of the SCSI drive onto that new partition. Moved the FreeDOS drive back to my laptop and copied the image to my laptop.

As I mentioned in the 1st post the Compaq has 2 original drives (not counting the IDE drive with FreeDOS on it). For some reason I can't mount the Compaq IDE drive (Conner CP3201G - 212Mb) on my laptop using my IDE->USB adapter. The adapter seems to be misinterpreting the old ATA responses from the drive - at least that's what ChatGPT thinks - who knows if it's correct or just making stuff up.

So, now I decided to see if I could get an image of the original Conner IDE drive. But instead of using the FreeDOS drive to store the image, I noticed when the Tom floppy is booted it recognized I had a 3COM ethernet card installed. I gave it an IP address on my lan and with a bit of network voodoo transferred an image of the Conner IDE drive directly to my laptop.

So my main goal has been accomplished. I'm not exactly sure what I'm going to do with these drive images, but it was interesting to see if I could do it with my limited resources. Maybe I'll see if I can recreate the Compaq as a VM?

There's still a couple curiosities I might investigate, but I probably won't spend too much time...

1) Is ChatGPT correct that my IDE->USB adapter doesn't understand the ATA responses from the Conner drive and if so is there a way around it?

2) I wasn't able to connect both the Conner IDE drive and the WD Caviar IDE (FreeDOS) drive to the Compaq at the same time. I'm guessing some kind of master/slave issue I didn't get quite right.

The actual GHOST is a dos booter, everything else on the cd is fluff as far as I’m concerned.