Kaypro: 81-149C vs. 81-232

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Mon Mar 23 04:37:03 1998

On Sun, 22 Mar 1998, Don Maslin wrote:

> Interesting! Take a look at the back side of the II's drives and see if
> you can identify the small black 'cable' that leads to the head. It will
> move as the heads move. Anyway, if you spot two, then the machine has
> double sided drives and that could be the reason that the 2's drives -
> single sided - cannot read the disk.

Both machines have single-sided drives, and the disk I have is definitely
single-sided.

> If you compare the part numbers on the motherboards - assuming that they
> are there - you will find that the board on the II is an 81-110, whereas
> the 2 should be either 81-184 or 240. They are not the same board.

The 2 has an 81-240A. I can't find a number on the II's motherboard.

> > Anyway, the only other thing I could try is to make drive B in the 2 think
> > that it's drive A, to see if I can boot from there. Does anyone know how
> > these drives decide which one's A and which one is B? And can I switch
> > their identities without removing the drives from the metal housing? I
> > don't have the proper screwdriver to remove the drives.
>
> This is usually set by a socketed DIP jumper plug on the drive circuit
> board located near the ribbon cable connector. It could be a DIP switch,
> but not usually. If the DIP jumper plug and they are both in the same
> position, just swap them. If they are in different positions, then swap
> the positions on both drives. These DIP jumper plugs have a frangible
> strap between opposing pins, and usually all but one or two are broken.

All I can see through the back is what looks like a blue 16-pin DIP chip
in a socket labeled "2F" in drive B and not drive A. This is probably the
jumper plug you're talking about. I can't see the top surface, so I can't
see if there are straps, broken or otherwise. I could probably remove the
thing from drive B, but inserting it into the other drive would be
impossible without removing the drive from the metal housing.

Of course, if I simply removed the part from drive B, and connected the
ribbon cable to B and not to A, it might work. I'd rather not have
another loose part to keep track of until I get the right tool to
reinstall the thing, though. :/


Doug Spence
ds_spenc_at_alcor.concordia.ca
Received on Mon Mar 23 1998 - 04:37:03 GMT