Kaypro: 81-146A vs. 81-232

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Sat Mar 21 04:37:15 1998

I finally opened up my Kaypros today to see if I could get the '2'
working. The II and the 2 seem to be almost identical inside, with two
notable differences: One of the ROMs has a different number on it, and
my Kaypro II has some wires soldered between pins on one of its chips.

The Kaypro II has a chip with a sticker marked "81-146A", with the "A"
stamped on in read ink. The Kaypro 2 has a chip with "81-232" on it, in
the same location.

What are the differences?

The chips at position U87 on both motherboards are marked DM74LS390N, but
the one in the Kaypro II has been messed with. It's a 16-pin chip, and
pin 1 has been bent upward and a wire soldered onto it, which leads to pin
6. Pin 9 is missing. Pins 12 and 15 are attached with a wire.

Is this normal for a Kaypro II, or has someone made a modification?


Anyway, I managed to make a copy of the WordStar disk that came in the
drive of the II today, using my Amiga 1000, A1060 SideCar, A1020 5.25"
floppy drive, and TeleDisk. So now I have a disk that boots reliably
instead of 1 out of every 5-10 times. That meant that I now know there's
something wrong with the Kaypro 2, because it won't boot at all with the
new disk. Before, it may have just been a borderline disk that was
causing the problem.

So (tell me if this was a bad/dangerous thing to do) I opened both
machines up and attached them to each others' disk drives. They were
plugged into a power bar, so I powered them up simultaneously with that.

The Kaypro 2 boot up with no problems, using the II's drives, and the II
was incapable of booting using the 2's drives, so I've got the problem
located to drive A of the Kaypro 2 now.

And BTW, both the II and the 2 have full-height drives.

Both keyboards have missing keys (including broken plungers). Will this
be easy to fix?

I'm thinking of fixing the 2, and using the II for parts, simply because I
like the colour of the 2's green phosphor monitor better (and some other
minor things). :) Is one model more rare than the other? IOW, does one
warrant saving more than the other? If not, I'll go with my feeling and
fix the 2 with parts from the II.


Doug Spence
ds_spenc_at_alcor.concordia.ca
Received on Sat Mar 21 1998 - 04:37:15 GMT