tlz@drutx.UUCP (ZrustTL) (10/30/86)
<eat it, sucker>
Just thought I'd let you know about the SF354 upgrade to DS
that I just did. Since I haven't seen much about this on the net
either 1) no one cares or 2) not many folks have done it yet.
Assuming #2, I will proceed.
For those of you that don't know, upgrading your SF354 to DS
consists of replacing the drive mechanism inside the disk
drive box. The replacement drive fits the same physical and
electrical interfaces (almost), so you basically just pull out
the old one and stick in the new one and your done.
I ordered the Epson double-sided drive mechanism from B&C Computervisions,
3283 Kifer Rd., Santa Clara, CA 95051 (408)749-1004 for $100
plus $5 s/h. Just ask for the 'double sided Epson drive upgrade
for the ST' and they will figure out just what you need (none
of this part or stock number stuff, please). I got it about
5 days later. It came with no specs or anything of that sort
(certainly no instructions for installing it in the SF354 box),
just a little drive mechanism in an antistatic bag.
WARNING! THIS IS A CLEAR-CUT WARRANTY VOIDER (oh, come
on, everyone can figure that out, can't they?)! I
TAKE NO REPONSIBILITY FOR ANYTHING THAT YOU DO TO YOUR
SYSTEM, BODY, PLACE OF RESIDENCE OR ANY OTHER FACET
IN THIS LIFE OR ANY OTHER LIFE, PAST OR FUTURE THAT COULD
POSSIBLY BECOME INVOLVED WITH THIS MODIFICATION!
PROCEED AT YOUR OWN RISK.
You'll have to dissassemble your SF354 by removing all seven
of the screws on the bottom. Note that three of these are
machine screws and the four corner ones are self-tapping kinds
(remember where they go). Next, unplug the ribbon and four
conductor cables from the drive mechanism. Remove two
screws holding the shield to the drive mechanism and slide
the shield off the back end. If you are adventurous, throw
away your old mechanism now or sell it to your hacker friend
for $120.
The drive has two obvious differences from the Atari (Sony?)
unit you are replacing. The busy light is on the wrong
side, the front bezel is the wrong color (black) and the
release button is much too large to fit through the front cover
on the SF354 box. Don't despair! Simply pop off the button
by prying in the two tiny hold down tabs on the back side of the button
and put it on the Epson unit after removing its button in a similar
fashion. Next, remove the front bezels on both drives by loosening
two tiny phillips head screws visible just inside the disk opening.
You can swap these, too (isn't standardization wonderful?}.
The tricky part (if you care about seeing a busy light and you
don't want to drill peep-holes in your SF354 case) is moving the
busy LED to the other side. I did it by unsoldering the small shield
covering most of the LED, unsoldering the LED (note the lead polarity),
attaching two small wires to the LED holes, attaching the other
ends of the wires to the proper LED leads (think of this as an
LED extension cord) and gluing the LED near the plastic light
guide Atari uses to couple their LED to the outside world.
Since the Epson LED is smaller, light output will be lower than it
used to be, but still quite visable. The LED from the Atari drive could
be used but I'm sure you would have difficulty squeezing it in
since there are other components on the PC board in this location.
My drive had an option jumper in the DS1 position. Pull this out
(fingers will do) and reinstall it in the DS0 position. There
are other options which I didn't fool with (BUT SEE THE NEXT
PARAGRAPH). Put the shield back on, cables back into the
mechanism, screws back in the case and you're set!
Well almost. I've found that unless I have a disk,
any disk (formatted or not) or probably any other flat, hard, 3.5"
square object in drive "B" (the Epson) when booting, the OS
doesn't recognize it at all. Perhaps there is some sort of
"disk in position" signal that should be disabled by an option
of some sort? Perhaps the drive is internally disabled when the
disk is removed. PLEASE post any fixes you know of for this
unfortunate condition.
Good luck!
--
Terry L. Zrust, AT&T Information Systems Laboratories
MS 30L49, 11900 North Pecos Street, Denver, CO 80234
ihnp4!drutx!tlz Voice: (303)-538-4547