Kaypro: 81-149C vs. 81-232

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Sun Mar 22 06:16:54 1998

Well, I've repeated what I did the other night. I plugged the Kaypro II
into the Kaypro 2's drives, and vice versa. Just the ribbon cable, not
the power. Whichever machine was plugged into the Kaypro II's drives was
able to boot, the machine plugged into the 2's drives just sits there with
the bootup message and eventually beeps and says "I cannot read your disk"
(or similar).

I tried swapping the II's 81-149C with the 2's 81-232. Neither will work
with the other's ROM. The machines light both drive lights and fill their
screens with garbage characters (many of which are flashing). I even
tried swapping BOTH the boot ROMs and the character generator ROMs
together, in case they depend on one another, but got the same symptoms.

So the ROMs aren't even compatible between machines.

I looked at the other chips in the vicinity of the ROMs, and all part
numbers matched. And there are no obvious differences between the
motherboards except for that wired-up chip I mentioned in the II.

Very odd.

Obviously I didn't follow all of the traces on the motherboards to see if
they matched. :)

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.


Doug Spence
ds_spenc_at_alcor.concordia.ca
Received on Sun Mar 22 1998 - 06:16:54 GMT