5150: Setting up XT-IDE (add simulated hard drive using CompactFlash)


Purist will frown and say “the IBM PC didn’t support a hard drive!” That’s true, on release, PC-DOS 1.0 and the then-delivered BIOS of the IBM PC didn’t do well in supporting fixed disks. But the BIOS issue was resolved in 1982, new ROMs could be installed, and PC-DOS 2.0 did add fixed disk support. So the system as a whole would support a fixed disks, just the software (in ROM and PC-DOS) had to catch up.

Wikipedia has a great chart that presents all the features of the various DOS versions and alternatives:


The XT-IDE will work just fine in a 5150, you don’t need an actual IBM PC XT.

What is XT-IDE

I used the XT-IDE Deluxe as available from Monotech (see here). And I used a 128MB CF (CompactFlash) card that they provided. This CF card includes MS-DOS 6.22 and Windows 3.11 pre-installed.

That’s great, but I only had 256KB RAM and MS-DOS 6.22 won’t boot for that. [ I later ordered the RAM upgrade that attaches directly to the XT-IDE – which works very well and avoids consuming an extra expansion slot ]

I then accidentally corrupted my CF card. I used a very old CF USB card reader that I had, and for whatever reason, the CF card content was lost after I removed it from the USB device. So I then ordered a brand new modern CF card reader. While waiting for that, I took practice at re-initialize the CF card myself.

This meant booting suitable versions of PC-DOS, MS-DOS, or DR-DOS using my HxC2001 Disk Emulators. DR-DOS 3.41 was the earliest version I could find that supported 128MB partitions (whereas earlier versions of DOS only support 32MB partitions – with PC-DOS 2.0 supporting even smaller).

Also, I only had 256KB RAM. All versions of DOS 4.0 or newer wouldn’t even begin the install, stating that I had insufficient memory. So, again DR-DOS 3.41 worked – it could install with having only 256KB conventional system RAM. However, the install just initialized the partition and didn’t actually complete (for some other unrelated reason). So I just SYS C: the drive myself (I don’t believe I had to use FDISK, the DR-DOS installer may have done those parts for me). Then I just copied all the DR-DOS disks to C:\DRDOS. Rebooted, and DR-DOS 3.41 was working from the XT-IDE.

About 10 days later I got the RAM upgrade card, 2nd XT-IDE, and several more CF cards with MS-DOS 6.22/Windows 3.11 as backups in case the CF card becomes corrupted again. But I haven’t bothered to install any different version of DOS, as so far everything I want to run is working fine.

For 2nd (CF) HDD (Hard Disk Drive)

To power a 2nd HDD extension off an XT-IDE, you can borrow the power plug from one of the disk drives (since you won’t be needing disk drives anymore, right?!).

TIP: Remove the jumper to make the 2nd IDE a slave to the master one on the XT-IDE.

But because of the 5-slot limitation of the IBM PC 5150, I just run a single XT-IDE with 128MB CF (Compact Flash) using DR. DOS 3.41 (installs and boots in under 256KB RAM and supports 128MB partitions).

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