david@ms.uky.edu (David Herron -- Resident E-mail Hack) (03/21/88)
I just went through a slightly scary experience with my A2000. I was
trying to add an off-the-shelf 3.5" drive (Sony MP-F63W-01D) as an
internal drive and somewhere in the fiddling broke things -- a blown
surface mount transistor in the disk drive and something in the on
board drive electronics. I think that during the fiddling I might
have plugged the power cable in backwards -- which is a neat trick
considering how the power cables are constructed.
(BTW, my machine was out of warranty :-().
Anyway, while talking to my local dealer I asked him about the sort
of drive I can use, and he's under the impression that there is some
sort of special drive you have to use for Amiga's. Now, he's a nice
guy and everything but he doesn't seem to be fully at ease with
hardware issues. (His repair work is done off site by somebody
who I feel confident of). Anyway, I thought I'd ask y'all.
Anyway, I just took a look in the Hardware Reference Manual (HRM?) and
found out that there is *one* difference -- the drive is supposed to
remember the state of it's motor. It didn't talk about any other
differences. Is this an important difference? I suppose one of two
things would be different. Either the drive will pay attention to the
motor line all the time and whenever any motor is supposed to run this
one will also run, or the drive will spin down whenever it's not
selected. The first difference would put some extra demand on the
power supply, but I've got an A2000 here ... the second one could make
things a little bit slower in situations where you're "jumping" from
one drive to another.
I think it's kind of ridiculous to pay $200 for an add-on drive that'd
just be a bare drive when I can buy (and already own) bare 3.5" drives
for $130 ... I *don't* mind paying that much for an add-on drive
that also includes case & power supply.
--
<---- David Herron -- The E-Mail guy <david@ms.uky.edu>
<---- or: {rutgers,uunet,cbosgd}!ukma!david, david@UKMA.BITNET
<----
<---- "Oh, I dunno -- I think Sean would be rather tasty!" -- Beckytomb@hplsla.HP.COM ( Tom Bruhns) (03/22/88)
Anyway, I just took a look in the Hardware Reference Manual (HRM?) and found out that there is *one* difference -- the drive is supposed to remember the state of it's motor. It didn't talk about any other . . . -- <---- David Herron -- The E-Mail guy <david@ms.uky.edu> ---------- I think this just refers to the interface ckt between amy and the drive. It basically is a latch, and a circuit to echo back the hex FFFFFFFF that the hw manual also mentions (or 55555555 in the case of a 5-1/4" drive). I built the intfc ckt for a 5-1/4 and found it worked fine, except that I had to latch the (step) direction line; my particular Fujitsu drive wanted it held for longer than the hundred or so microseconds amy held it after a step command. So -- the Sony drive should be fine if it's like the one I have a manual for. My comments refer to external drives for an A1000 -- don't know just what they put in an A2000, and how much the drive+intfc is supposed to supply in that case. Tom Bruhns ...!hplabs!hplsla!tomb