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Date   : Fri, 24 May 1991 09:59:18 IST
From   : "Jacques J. Goldberg" <PHR00JG%TECHNION@TAUNIVM.TAU.AC.IL>
Subject: Re: INFO-CPM Digest V91 #94

Re. Kaypro II can't boot from disk A.

Very simple.
As always, there is IBM (which ignores the rest of the world) and the rest
of the world.
Since KAYPRO belongs to the rest of the world, I assume that the common 34 wire
flat cable was left intact with all wires parallel. On each of your
drives there is a set of jumpers where you almost certainly will recognize
that ONE of DS0 DS1 DS2 DS3 is jumpered; DS0 on your present A, DS1 on your
present B is ALMOST certain. Just exchange the position of these jumpers.
You will also notice that on ONE drive board there is a vacant socket compared
to the other. The vacant socket MUST be on the drive which is NOT at the end
of the cable, the thing in the socket which looks like a chip is a set of
resistors terminating the flat cable for correct impedance. Be EXCEEDINGLY
careful not to break its legs if you try to relocate that pseudo-chip on an
other drive, when you remove it.

The caveat about IBM is that for reasons which my limited brain was unable to
understand, BIG BLUE of course can't use the DSn jumpers for what there were
designed for, and obtains the same result by crossing a few wires in the cable,
which then ceases to be flat between the first and the second drive. In this
arrangement, both drives have the jumper selection in the same position.

Finally, some old (or is it recent) drives have the jumpers labelles DS1 to
DS 4, not DS0 to DS 1. Just in case some reader might need such clarification.
Also, it is NOT a Law of Nature that the lowest drive is A etc... The system
generation software with my LOBO MAX-80 allows to change these assignments.
Even if the KAYPRO has the same capability, it won't help, since you can't
boot your machine, **BUT**, if the Kaypro HAS this software, and you can run
it to write a new boot disk on an OTHER machine, then you could get a boot
from drive B without opening your machine.

                                         Jacques J. Goldberg
                                         "Prof. of Physics"

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