It's good to know it's probably not the SCSI controller.  Honestly, that would be pretty poor product design if just plugging in a cable wrong could cause it to explode.  Also, if the chip was just flat out blown you wouldn't think it would read anything at all, whereas it does seem to get something, it just doesn't totally work. 

I still wonder if there's some sort of read issue though.  I can boot from floppy alright, but I tried booting from the hard drive three times and each time it got to a different point in the loading process before it freezes up or reboots.  If it were just due to corrupted data on the drive I wouldn't expect the results to be different each time I tried booting.  Then again, this is by far the oldest computer hard drive I've ever dealt with, so maybe it could be doing something weird.