First post, by eesz34
I'm using a 286 motherboard with no built in I/O, so it has a super I/O card (this one https://i.ebayimg.com/images/g/1EcAAOSwMyRjfnYk/s-l1600.png).
I found out that when I change disks, it gives me the same directory listing. I changed the cable, then the drive, and it still does this. When I reboot it then gives the correct listing.
I actually have another of these I/O cards and they were NOS, and this doesn't occur in the other computer. I haven't swapped cards yet, but I checked the soldering and trace for floppy pin 34 and it looks good. I'm using DOS 6.22, and still have the problem when I skip config.sys and autoexec.bat with F8.
Is there a utility I can use that will tell me if the disk change signal is toggling? I have not yet got my logic probe out to test pin 34, but I find it unlikely two cables and two drives have the same problem. Is this a BIOS function, or does DOS read the floppy controller directly?