Hello! I'm in a bit of a spot and am hoping you might be able to be of help!

So a few months back I managed to obtain an old Toshiba T3100e/40, an 80286 "portable" computer in, to me at least, surprisingly good condition - which is to say that so far the only thing I've tested that hasn't worked on it was the old BIOS battery; even the old 40 megabyte HDD is still entirely in working order, or at least is so far. And since the HDD still is working, I figured I should attempt to preserve a copy of its contents as one of the first orders of business.

Problem is, I don't have any other PCs old enough to still have an old IDE interface, and with the T3100e having seemingly been introduced just as the IDE standard started becoming a thing, I'm guessing the drive might not be 100% according to what more modern IDE controllers might expect - at least, the USB to IDE converter I tried couldn't make much sense of it, thinking the drive was on the scale of hundreds of gigabytes which it really isn't. So with that path locked to me, I decided to attempt the XT-IDE approach using an XT-CF-Lite 4.1 card which is working better but not better enough to pull it off, which is basically why I'm asking for help.

What happens is... if I boot the computer with the XT-CF-Lite card installed but no actual CF card plugged in... the XTIDE bios starts up, finds no drives on its own interface, and successfully boots the C drive's Toshiba Personal Computer MS-DOS Version 3.30, but... if I boot it with a CF card present, the XTIDE bios starts up, finds the CF card, attempts to boot C»C... and nothing happens. The computer basically remains hung in that state. If I try to circumvent this by instead booting from FDD with a DOS 5 floppy disk, it does boot... but while the CF card is accessible (I've been able to FDISK and format a partition onto it accessible as D:) the 40 Mb C: drive gives Invalid media type reading drive C, Abort Retry Fail. FDISK still detects a 41 Mb partition on the drive and that it's been mapped to C:, but somehow for reasons utterly beyond me, the XTIDE BIOS detecting a CF card makes that C: partition effectively unreadable?

It's probably worth mentioning that this is all with XTIDE version 2.0.0β3+ (2013-04-03) (R528?) that came with the XT-CF-Lite 4.1 card; I've made a few attempts with an updated R625 version of XTIDE but with that it doesn't even seem to be able to boot period whenever a CF card is plugged in, the computer just hangs entirely after drive detection and doesn't even let me select booting from the A: drive.

I'm quite at a loss with all of this - I do not understand why XTIDE detecting the CF card suddenly makes the regular drive's C: partition unreadable, and nothing I've attempted so far has made that much of a difference. It's really quite perplexing.