Some ideas:
-try to hold shift down while booting to boot clean
-does the system boot from a floppy that has a config similar to that of your CF (himem, emm386, .sys drivers...)?
I'm thinking memory issues or instabilities irrelevant to the CF card.

LChackr wrote on 2023-07-17, 04:35:

The primary storage is a 512MB Compact Flash drive using IDE adapter I've successfully used with other 386 and 486 builds in the past.

How do you mean? Is the IDE adapter tested on other systems, or the card? Or both?
In my experience any CF card that has the removable bit set (and with it the magnetic media type bit is not set) is going to cause problems. This depends on the BIOS and particular IDE controller card. Prime 2 / 2C usually work best but if the BIOS is stubborn even these controller can't use the card.

Maybe it's just my luck but from like 5 CF card of 512MB only one reports as fixed (non-removable) magnetic media, and that one works on everything. It's a SanDisk SDCFB-512. Other cards... depends, usually not on older mobos like 286 and early 386.

I'm not sure, but I had some trouble with a couple CF cards until I first fixed the MBR before formatting and loading the OS. Maybe you can try that

fdisk /MBR

see here for info on XT-IDE. Not sure if this is your interface or not:

https://minuszerodegrees.net/xtide/XT-IDE%20-%20Problems.htm

Seaken

+1 for FDISK /MBR

I would also perform the "clean" command on the drive as explained here: https://www.seagate.com/gb/en/support/kb/how- … rompt-005929en/ (this is done by using the command prompt under modern windows)

basically I would "clean" the CF, do the FDISK /MBR and then go on and use it on a retropc

Yes, I think I also did a "clean" using my Win10 machine on a couple of CF cards. It's been a while since I setup my CF cards but now that @keropi mentions it I do recall doing the clean also.

Seaken