LoudLad wrote on 2020-05-21, 15:50:

Hi Fellas, bit of an odd one: I have a pentium 90 machine using this exact motherboard. I got a CF+IDE adapter, but when plugged […]
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Hi Fellas, bit of an odd one: I have a pentium 90 machine using this exact motherboard. I got a CF+IDE adapter, but when plugged in seems to force the CD drive to be non responsive. No drive light, no opening.

Things I have tried:
Switching cables - no difference, CD drive non-functional
Playing around with the slave/master jumpers - no such luck (maybe I'm doing it wrong)
Pulling the IDE cable from the CF adapter - CD drive is functional

I didn't think I would have had to fiddle with the slave/master jumpers anyway since they're wired into separate IDE sockets on the board, but there's likely things I don't know. I'm looking through the board manual to see if there's some special case I need to keep an eye out for, but I haven't found anything yet.

Any ideas?

Well... the drives with built-in controllers (IDE) had to talk to one another to control the flow of data on the shared bus and cable. Maybe the CF-to-IDE adapter is not backwards compatible far back enough? Early Pentium systems such as yours didn't necessarily even have Ultra DMA, so if the adapter is backwards compatible to say... U-ATA66 or U-ATA100, the board or the CD-ROM drive might get confused when negotiating the transfer rate.

You could also have a bad PATA cable.

edit: Which way are the cables facing when you insert them? The old rule of thumb was that the edge of the PATA cable marked red, would be towards the power cable of the IDE-device. Does the CF-to-IDE adapter clearly indicate which way the cable is supposed to go?

Aaaah the Endeavour... How long are your PATA cables? Try shorter cables at least for your CF-adapter thingy. If using UDMA cables, make sure you put the drive on one end, the other end on the motherboard. Some of those cables are keyed, put the master or slave device in the wrong position, nothing works.