(moved to right thread 😀 )
I was trying to install DOS, btw. not Windows, for testing some 486 boards and accessories. I spent another hour on the CFs today and threw them back in the bin (2 adapters and 2 CF cards, one 256M and one 8G). I could fdisk, format, copy files, but they wouldn't boot, and worse when they were in the system with *any* drive other than a floppy, for example the CF plus a HD, no matter what the master/slave relationship the system would try to boot the CF and fail. It seemed to steal the boot priority. One of the two adapters has a master/slave switch but it doesn't affect the problem.
I switched to a ISA/PCI 486 board and, after I got it set up, it wouldn't detect drives - well, by default the IDE is disabled, so that's fine. Detects, but detects a master drive as a slave and gets the name right and the parameters wrong. Even setting them manually doesn't get anything other than disk boot failure (2Gb Fujitsu with 500mb first partition I had just used on the previous DOS 486). The board support LBA, but won't detect CD-ROMs and thinks all HDs are on slave, whatever is set on the drive.
The good thing is the previous board was fine, memory and CPU fine despite momentary parity errors caused by... the ISA video card, a Sigma Designs 5GK-ACMVGA 256k with a mysterious jumper marked OWS/IRQ2/OWS-BIOS... it came set to OWS and worked fine in the P2, it would cause memory parity errors (and screen text corruption) on the 486 until I switched it to BIOS. Works fine. Little slow. Designed in Milpitas, CA, as an aside.
Luckily I have other ISA/PCI motherboards, and I already compared ISA and PCI boards on the P2, but I'd rather have this one working before I put it back on the shelf. I need to know when to postpone a project.
As far as the CF goes, none of my current systems have a CF reader, I need to set up a later system with that, like one of the 775s, and try using BootIt or whatever to deal with it rather than trying to format it from DOS/UBCD - which seems to sort of work but fails. It would save time and wear and tear to use it (they're the type that plugs directly into the board). I actually have two laptop IDE CF adapters, one of which supports 2 CF cards.
I also need to test the $1.49 Blu-Ray external mini USB drive. Needs a power adapter and not marked (well, it's center positive - my adjustable power supply doesn't go down to 5V, which is where I'd prefer to start).