22 May
1998
22 May
'98
2:43 a.m.
A while ago I got a Kaypro 4'84 system for free and have been trying to bring
it back to a state of stability and usefulness. The system as a whole was in
good shape; my problems have been with the disk drives.
I had hoped it was "only" old, worn-out disks that were causing the problem
(and the disks are worn-out, as tests with 22DISK on a school PC show) but the
drives themselves seem to be flaky. (Either that, or the new Verbatim disks
I bought are substandard.) My worst fear is that the drives are corrupting the
disks somehow. (Can this happen even when no writing is involved?)
I have two spare drives; one is evidently SSDD and the other is DSDD -- I have
not tested them. Only the DSDD drive is really suitable. These are, IIRC,
96-tpi MFM drives. They are made by TEC. (Not the same as TEAC, I suppose.)
I would just put one in, except that I'm not sure if I need to do anything to
align them. Even if I did need to, I undoubtedly don't have the equipment.
Is alignment really important? What about on new drives?
Could cleanliness be a problem? (I cleaned the heads with a head-cleaning kit
a while ago; I put the dust cover on the computer for some time but stopped;
however, the keyboard latches in front of the drives anyway. I keep the doors
closed and the shipping inserts in the drives; I definitely have been careless
about the order of inserting/removing the inserts and opening/closing the
drives and turning on/off the computer.)
It's very unsettling to think of my software eroding as I watch. I haven't
found replacements for some of it. I've tried using 22DISK; there are two
problems with this: 1) It doesn't like my formats very much, and 2) I've been
using PC's in the computer lab and I don't trust those drives any more than
mine! I may haul an ex-roommate's Korean '386 box out of the closet if I get
desperate.
The Apple ][ disk drives I've seen have had flawless performance; even PC 5.25"
drives seem to do very well. I'm getting very tired of hearing my machine
go "grkgrkgrkgrk ... grkgrkgrkgrk ... grkgrkgrkgrk ..." (It's one of those
sounds that is instantly annoying and recognizable by pure instinct as a Very
Bad Sound. I wonder what a list of those sounds would look like?)
Thanks,
-- Derek
22 May
22 May
10:20 a.m.
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2:26 p.m.
My least favorite disk drive noise is "skrch!" Think Seagate.
(and no, I don't mean they're all bad. I've got two Medalist 1080's here
that have been running essentially 24/7 for two-plus years, and they're
fine. But when you get a bad Seagate it goes "skrch!" and you throw it
away, and I know from lugubrious experience that you're not going to get
the data back off it just by wrapping it in plastic and sticking it in the
freezer overnight.)
__________________________________________
Kip Crosby engine(a)chac.org
http://www.chac.org/index.html
Computer History Association of California
2:37 p.m.
On Fri, 22 May 1998, D. Peschel wrote:
A while ago I got a Kaypro 4'84 system for free
and have been trying to bring
it back to a state of stability and usefulness. The system as a whole was in
good shape; my problems have been with the disk drives.
I had hoped it was "only" old, worn-out disks that were causing the problem
(and the disks are worn-out, as tests with 22DISK on a school PC show) but the
drives themselves seem to be flaky. (Either that, or the new Verbatim disks
I bought are substandard.) My worst fear is that the drives are corrupting the
disks somehow. (Can this happen even when no writing is involved?)
Remotely possible, but not likely.
I have two spare drives; one is evidently SSDD and the
other is DSDD -- I have
not tested them. Only the DSDD drive is really suitable. These are, IIRC,
96-tpi MFM drives. They are made by TEC. (Not the same as TEAC, I suppose.)
With your PRO-884 MAX ROM, you should be able to install and use the 96-tpi
drive and it should double step and read your 48-tpi disks. As a general
rule, however, it is not wise to write to a disk that has been formatted
in a 48-tpi drive.
I would just put one in, except that I'm not sure
if I need to do anything to
align them. Even if I did need to, I undoubtedly don't have the equipment.
Is alignment really important? What about on new drives?
Alignment is somewhat important, but only critical if you are moving
disks between different machines. Since you were able to read the disks
that I sent you, I would presume that they are not all that far out.
Could cleanliness be a problem? (I cleaned the heads
with a head-cleaning kit
a while ago; I put the dust cover on the computer for some time but stopped;
however, the keyboard latches in front of the drives anyway. I keep the doors
closed and the shipping inserts in the drives; I definitely have been careless
about the order of inserting/removing the inserts and opening/closing the
drives and turning on/off the computer.)
Your 'keep clean' precautions are overkill unless you live in the midst
of a dustbowl. While it is always wise to eject the disk before
shutdown, I have not lost a disk that way in years on any of the various
machines that I use - CP/M and DOS.
It's very unsettling to think of my software
eroding as I watch. I haven't
found replacements for some of it. I've tried using 22DISK; there are two
problems with this: 1) It doesn't like my formats very much, and 2) I've been
using PC's in the computer lab and I don't trust those drives any more than
mine! I may haul an ex-roommate's Korean '386 box out of the closet if I get
desperate.
Sydex' 22DISK is quite capable of handling the Kaypro formats without
problem. It may be, as you suggest, that the drives on the lab machines
are the problem. If possible, I would suggest booting to DOS rather than
running in a DOS window when you run 22DISK, though.
The Apple ][ disk drives I've seen have had
flawless performance; even PC 5.25"
drives seem to do very well. I'm getting very tired of hearing my machine
go "grkgrkgrkgrk ... grkgrkgrkgrk ... grkgrkgrkgrk ..." (It's one of
those
sounds that is instantly annoying and recognizable by pure instinct as a Very
Bad Sound. I wonder what a list of those sounds would look like?)
I'm not sure, but I think that it has to be terminated with something like:
AAAAARRRRGGHH!!! Oh, @&%$!!!!
- don
Thanks,
-- Derek
5:06 p.m.
D. Peschel wrote:
A while ago I got a Kaypro 4'84 system for free and have been trying to bring
it back to a state of stability and usefulness. The system as a whole was in
good shape; my problems have been with the disk drives.
I have two spare drives; one is evidently SSDD and the
other is DSDD -- I have
not tested them. Only the DSDD drive is really suitable. These are, IIRC,
96-tpi MFM drives. They are made by TEC. (Not the same as TEAC, I suppose.)
_Maybe_ a Kaypro 4 can use 96-TPI drives, but I wouldn't bet the
ranch. You want 48 tpi drives - real DD, not 96 tpi, QD or worse
HD. There are a gagload of such drives available, gut any 8088
PC you find at the curbside.
--
Ward Griffiths
They say that politics makes strange bedfellows.
Of course, the main reason they cuddle up is to screw somebody else.
Michael Flynn, _Rogue Star_
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