Hi there! Do you mean MS-DOS 3.30 or IBM PC-DOS 3.30? PC-DOS 3.30 was quite popular.

tony359 wrote on 2023-04-29, 14:30:

I was sent an old version from 2013 (XT) and that worked! I could see the CF, I could FDISK it, format it and install DOS 3.30 with "select".

However, the system freezes when it's time to boot. XTIDE says Booting C>>C and that's it, I have to power cycle. However if I boot via floppy, I can access the CF, see the files and everything.

Possibly the MBR on that CF card does not contain the required boot code. You can write working boot code to the MBR using "FDISK /MBR". I'm unsure whether this already works with DOS 3.3, but it should work with DOS 6.22. This means you need a 720KB DOS 6.22 boot floppy with FDISK on it.

Thank you.

@jo22 - IBM PC-DOS 3.30. I'd like to restore this machine as it was in the '90s!

@mkarcher
I did try FDISK /MBR but that did not help either. I also did not receive an error so I suppose it works with 3.3?

Ideally, I'd like to install DOS 3.3 to restore the machine as it was when I used to use it at school in 1992. If that is not possible, I know I have the 6.22 option.

Still, for the life of me I cannot get ANY of the modern ROMs to recognise the CF (not boot, just recognise it). The only ROM which sees the CF is the one I was sent from 2013. However, the modern AT ROM works 100% on my Pentium machine.

To clarify, I did FDISK'd and Formatted the CF under IBM DOS 3.3.

Thank you!

Hm. Tricky. I don't have enough experience with PS/2 platform, I'm afraid.

Thing is, an XT platform BIOS usually wasn't combined with 80286 processors (accelerator boards excluded).
And AT platform BIOS wasn't paired with 8086/8088 processors.

The PS/2 BIOS is a special case, though.
It had been paired with 8086 to 80386/80486 processors.
So you ideally want a PS/2 build of XUB.

The PS/2 BIOS also is partially AT BIOS compatible, but does certain things in a different way.
It also added BIOS routines exclusive to the PS/2 series of PCs.

In some way, the PS/2 platform was a fork to the PC/AT platform, but one that wasn't fully AT compatible and became a dead end.
This may cause strange results with some option ROMs intended for XT or AT BIOS, I assume.

If you want to clean your HDD, you can run S0Kill. It will clear track 0 and the MBR.
Re: IDE to Compact Flash as MS-DOS boot drive.

Then, the HDD looks like fresh from factory to software.
DOS 3.3 may have no trouble writing its own MBR then, because no left over data is present that could potentially confuse it.

Alternatively, you can try doing a manual SYS C: from diskette after installation.
It might write a new boot sector to C:, not sure if that's enough to fix your problem, though.

Good luck! 🙂🤞

Thank you.

There is a plot twist. I tried installing 6.22 and everything worked fine (after an FDISK /mbr). So I thought it was just a 3.30 limitation.

Just to double check, I tried again. I booted from the 3.30 floppy, SELECT told me that the CF drive parameters were invalid (DOS 6.22 partition, way too big!) so I popped the CF into my Windows and deleted the partition (previously I did a DISKPART/CLEAN, maybe that's the difference?).

I then put the CF back to the PS2, ran FDISK, created a large 32MB primary partition then ran SELECT and let it complete.

Surprisingly, everything works now! The only difference is that this time I didn't clean the CF with DISKPART.

The above is still using a 2013 ROM. If I use anything newer, the CF is not recognised when the XT-IDE boot screen appears. I mean, I can live with the 2013 version but I am a curious person and I'd like to understand why the new ones don't work! Any ideas on that one?

Thanks so far.