28 Jul
2005
28 Jul
'05
1:34 a.m.
On Tue, 26 Jul 2005 21:02:47 +0100 (BST)
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
THe HDAs were not field-repairable, but the PCBs certainly were/are.
The IBM PC series TechResf contain schematics of some such drives
(which ones depends on exactly which version fo the TechRef amd which
updates you have). I've traced out a couple more. In general these
drives are not particularly complicated, although there may well be
ASICs for things like head switching, motor control, etc.
At one point I grabbed a copy, I don't know where I got it, but think it
was from a Tandy 4000 Technical Reference Manual, of a Technical
Reference the ST-225 (the old classic 20 meg ST-506 drive that EVERYBODY
had back then.) I believe it has schematic diagrams. The bad thing is
that it's in a file cabinet behind a BIG pile of gear right now.
Correct. Don't uou have at least one
ST506/ST412-interfaced drive
schematic?
Nope, unfortunately not :-( I've got various manuals for bridge
boards, which of course have the connector pin-outs in (and give
some of the theory), but nothing for a complete hard drive (I
suppose I'mactually surprised such schematics ever escaped the drive
manufactuers to be honest, as presumably ST506/412 units were never
supposed to be field servicable?)