Hi,

Rare things on this computer... First it seems external case (from NCR PC810 and 386 ones) is fitted on NCR PC8 chasis because as I remember that orange button is from PC8 version. Second that BIOS is not the genuine NCR bios, so it is possible that maybe inside the computer someone put another BIOS chip on your NCR card, if it is a NCR card. If you share some inside pictures I can clarify you. NCR bios for these computers does not accept CHS configurations, only types 1 to 47

regards

it may simply not be possible, not all BIOS allows custom type entry

sometimes you had to actually patch the values directly into the EPROM with a programmer

I played with it some more, and for now, I will leave it, as I plan on swapping in a DX-20 or 25 MHz with a better BIOS. The original motherboard that came with it had some bodging done to some kind of resistor network on a 4x4 slot, I don't know what went on there but it looked melted. The OG board didn't POST, so I put in this random SX 16 386 which was at least era correct. I need also to get a volume control knob, and I also added a turbo and reset switch above the LED lights, I had no idea the power LED turned orange with turbo off - on my original system, I didn't know of any way to enable the turbo.