Ok, that is good. Now about that prompt you're getting for the manufacturer diskette...
1) is the floppy drive actually
working, because if it isn't, that's the #1 thing needs fixing. Use that DR-DOS boot-floppy-making utility and make a DR-DOS boot floppy with it, and see if the system can boot to an A:\ prompt with it. If not, maybe the floppy has no power cable (easy to overlook) or its data cable doesn't have the red wire on Pin1 on both ends, or the section of ribbon that's got a twist isn't between the floppy and mobo (it should be between them).
2) snack break. Ooops, wait
2) Look at the contents of the diskette that the Makedisk utility created, it should have some folders and some files on it. If it doesn't, something went wrong.
3) Make sure you did go into the motherboard BIOS and change the Promise's operating mode to IDE mode. If the controller still is trying to be a RAID controller then your IDE-mode drivers won't work.