23 Mar
1998
23 Mar
'98
7:23 a.m.
On Mar 23, 5:18, Doug Spence wrote:
Well, if the ones that don't boot do move the heads, and the light comes on,
sounds like the machine can "see" them and make them respond, but just
can't
read the data. It's still possible they're faulty, but if they're all
single-sided, my guess is that one pair is 40-track and the other is 80-track.
However, if this were the case, I'd expect that the boot would go partway (the
drive would probably read track 0 OK, but not any other).
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. > Usually there's a set of jumpers, or
sometimes a small DIL switch pack,
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.
That is almost certainly a terminator resistor pack, and doesn't affect the
drive selection. Whichever drive is whichever number, that pack belongs in the
last drive on the chain.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York