[comp.sys.3b1] hack report: my disk hurts

dt@yenta.alb.nm.us (David B. Thomas) (02/24/91)

Hello again, fellow unix-pc hackers!!  I've had some really
bad problems with hard disks, and thus have been pretty well
out of circulation for a while.  Here's the latest from yenta:


Death Of A Miniscribe
---------------------

My 6-month-old miniscribe 3085 started exhibiting bad blocks,
all on track 0.  It got worse and worse and worse, until finally
even the superblock wouldn't read.  Ouch.  The performance on all
other heads was flawless, but head 0 had apparently bit it.  Re-
formatting didn't help a bit.  Back it went for warranty service.


From bad to worse
-----------------

In the meantime I had just purchased a micropolis 71M disk
from a net.trade.  I put it online and it ran for about 24 hours
and then squeaked itself to a halt.  Turned out the little pad
that keeps the spindle from building up static was rubbing hard
and causing bad vibrations.  After a couple of tries, I got it
to run indefinitely without vibration problems.  Then the bad
blocks started, this time completely random.  I don't think
it's a problem with the head or surface, but with the electronics,
because I get errors anywhere and everywhere, and often, but the
retries almost always work.

I don't think I'll buy any more used disk drives.  I was impressed
with the quickness and quietness of this model, though, and
would probably buy a new one, if the price were right.


Seagate to the rescue! [sic -- read on!]
----------------------------------------

Just as the micropolis was getting to where I couldn't even
boot, I got a new disk drive.  Turns out that miniscribe model
is no longer available, so they substituted an "80M seagate".

I was just about to kick and scream, but it was an ST-1100 !!
This is a teeny 3.5" ST506 compatible drive that got rave
reviews at the BOF.  I gather that another company used to
make these (was it imprimis?) and seaghate bought that
company.  So it's really not a seagate in the worst and
strictest sense, although seagate gets the money, which
bothers me just a little ;-)

Anyway, the ST-1100 is a VERY nice drive.  Very quiet,
very small, very low power consumption, and crisp
response at that.  I think Craig Votava said he had
two of them mounted internally, with an extra fan for
cooling them.  They certainly wouldn't tax the power supply
unduly.

So far, zero bad blocks!!!  Finally!!


TWO DRIVES AT ONCE

Another neat thing I got to do recently is actually use the
two-disk motherboard modification I made a month or two ago.
I would be running two drives at once all the time, but I
don't have a power supply strong enough to spin them both up
at once, or a decent second drive.  (I DO have a couple
of ancient, clunky 10 or 20 meggers that would be great
for backups, though :-)  good idea, john milton!)

So last night my friend Ed brought his unix pc over and
so we could copy some stuff from my disk to his.  The
way we did it was: we opened up his unix pc and connected his
disk drive to his own power supply, but we wired the cables to
my unix pc as drive 1 (second drive).  Worked great!  I mounted
it and did the copies.


VOICEPOWER

I just bought a voicepower board (hi, Gil!) and I've been having
a lot of fun with it.  I wrote a little answering machine
program (7k source) pretty easily.  (Gil's was a bit elaborate
for me, and plus I wanted to write my own.)  Watta NEAT piece of
hardware!!  

Hmmm... I want to elaborate on this, but this message is awfully
long aready.  Stay tuned for the next action-packed posting!

					little david
-- 
Computer interfaces and user interfaces are as different as night and 1.