Here is an interesting problem for some of you PC oldtimers ;-)
I need some help with an old PC I am upgrading to run Linux. It used to
be a 286, now it is a 486. I wanted to put in a decent sized IDE hard
drive in the machine to replace the 40 meg seagate ST-251 MFM hard drive
with an unknown model # Western Digital controller, but the market value of
small IDE's is outrageous for its true worth. So I bought another ST-251 to
put side by side. I tested it by pulling out the old hard drive and put
in the new hard drive. Worked great. Now putting them together is where
the problems come into play.
I connected the two drives with the wide ribbon cable containing the 2
slots. I adjusted the jumpers in the back of the drives according to the
specs listed from Seagate, and with some help from the drive lights in
the front of the drive (Yes the LED's came built-in), got the correct
settings for the jumpers (I believe). The one connected to the middle of
the cable has drive select 1 jumber connected, the drive at the end has
the drive 2 jumper enabled. From now on I will refer to each HD
as Drive A1 and Drive B1 so as not to be confused with the floppy drives.
I connected the smaller cable from drive A1 to the drive 0 slot in the
controller, and I did the same with the other cable on Drive B1 going to
the controller's Drive 1. I set up everything in the Bios to recognize
both drives. Booted up the computer -- error cannot find drive D:, hit F1
to continue. When I hit F1, drive A1 boots up (and, of course cannot
find the other HD). Hmm...
So I switched the smaller (data, I believe) cables -- Drive A1 is now
connected to drive 1 on the controller, and drive B1 to controller's Drive
0. Same error, and B1 now boots up, with the other HD nowhere to be found.
Thinking that maybe the data cable connected to the controller's drive 1
slot may be bad. I switched the physical cables with no success, same
I need some help here. My first instinct is that the second drive needs
to be low-level formatted for the controller to recognize it, but it
doesn't make much sense, since it recognizes each drive if it is
connected to drive 0. If it does need low-level formatting, will the
lowlevel formatter in the BIOS be OK for this, and what about
auto-interleave. I've not worked with MFM much -- it's old and
complicated, and difficult to find documentation. Any help would be greatly
appreciated. Sorry about the length of the article, I wanted to present
as much info needed to be clear.