First post, by dave343
I acquired a Compaq 386s/20n PC, 20MHz 386SX, 6MB, with a 85mb drive. Initially I kept getting a settings error on boot up and it wouldn't keep the bios settings, but that was due to the Dallas 1287 battery being dead. I fixed that issue last night by soldering on a 2032 battery to pins 16 & 20 as per some helpful guides I found. Now I'm getting a 1782 Disk Controller Error on start up. I'm not sure if it's related, but the Compaq BIOS only allows you to select from a list of about 62 Hard Drive Types. Type 47, which I think is usually Custom? does not allow for modification. The 85mb hard drive that was installed and looks to be original, has Heads, Cylinders, and Sectors which don't match any of the HDD Types to choose from. There is a 84.3mb Type (I think 52) but it's sectors etc... are way off. I've also tried a 1.6gb drive and just choose a HDD Type that was 500mb.
So here is where it gets weird. Out of maybe 10 power cycles / reboots, twice it booted up without the Disk Controller error, and on that second time I was able to install Dos 5.0 on the 1.6gb (Type 42 for 510mb). After Dos wanted to reboot however, I got the Disk Controller Error again.
The IDE Cable looks undamaged, and the inside of the PC was very clean. The 1.6GB Drive and the 85mb original drive I can confirm are good drives as I tested them in a 486 system. Is there something else I can check? It would seem like a bad connection somewhere, because I'm crossing my fingers the on-board controller isn't dead/dying... The Floppy Drive detects fine and works good. The IDE connector is standard on the HDD drive but it plugs into a weird connector on the board side.
I haven't taken a pic of my own but here's one that's identical.