Kaypro: 81-149C vs. 81-232

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Mon Mar 23 04:18:38 1998

On Sun, 22 Mar 1998, Pete Turnbull wrote:

> I don't know much about Kaypros, but is it possible that one of the sets of
> drives is 40-track and the other is 80-track?

I don't know enough about Kaypros myself to answer this one.

> Or that one set is single-sided and the other is double-sided?

Both machines have single-sided drives. And the boot disk I'm using is
definitely single-sided, because I duplicated it using TeleDisk with side
0 only, and the copy boots up and runs WordStar just fine.

> When you start up the machine and it tries to boot, does a light come on,
> on the disk drive (which would indicate that the drive is being accessed)?

Yes. The light for drive A comes on, and the motors for both drives come
on.

I get the same response out of the machine whether I use the Kaypro boot
disk or an MS-DOS disk. But it is paying enough attention that it
immediately tells me "I cannot read your diskette" when I insert a
cleaning disk. :) [which makes cleaning a bit difficult]

Also, just for the hell of it (and it's probably a Bad Thing(tm)) I nudged
the head forward when the machine was off, to see if it would move when
power was applied. And it did move back to its usual position.

> > 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.
>
> Usually there's a set of jumpers, or sometimes a small DIL switch pack, which
> select one of four disk addresses. They may be labelled DS0, DS1, DS2, DS3 or
> perhaps D1, D2, D3, D4. D0=A and D1=B.

I'm afraid it's not that easy. I did pull out the flashlight and take
some good close looks inside the drives tonight, though, and I think I
know how it determines the drive number now.

At the back of the main circuit board, just in front of where the ribbon
cable connects to it, there is a 14-pin chip with a label "1F" beside it.
In drive A, there is an empty 16-pin socket beside it, with "2F" written
on the circuit board beside it. Drive B has something IN this socket - a
BLUE 16-pin chip.

Just in case it was simply a matter of a missing part in drive A of the
Kaypro 2, I inspected the Kaypro II's drives, and they were identical.
There's a blue 16-pin chip sitting in the socket of drive B, and not in
drive A. That along with the "2F" labelling seems to be pretty clear.

Now the problem is swapping that "chip" from one drive to the other. I
don't think I should even make the attempt without first getting the
drives out of the machine. Which means I need an appropriately-sized
6-sided screwdriver. :/

Doug Spence
ds_spenc_at_alcor.concordia.ca
Received on Mon Mar 23 1998 - 04:18:38 GMT