ard at p850ug1.demon.co.uk
Tue Jul 3 15:04:29 CDT 2007
> Spent a fun morning messing around with a PERQ 1, which is the first time I've
> ever got the chance to actually sit in front of a working example...
> A few questions:
> 1) The hard disk (Shugart SA4008) drive belt seems to have a habit of
> running 1mm or so out of line at startup, resulting in it rubbing against the
> chassis beneath the spindle pulley. Once it picks up speed it sorts itself
> out, but I was wondering whether there's any adjustment in either the spindle
> pulley or drive motor in order to get it to run a little better?
IIRC those pulleys are 'crowned' -- that is they are convex. The belt
will run towards the edge when it's running slowly, and will come to the
middle when it's up to speed. I don't know of anything you can do about
this. Maybe fiddle with the motor position, but....
The SA4000 service manual that I have has full schematics and PCB layouts
but nothing on the mechanical side at all.
> 3) Shutdown procedure - is 'bye' sufficient or do I need to be doing
> something else first? The manual's a little ambiguous on this (and 'bye' alone
> executes so unbelievably quickly that it made me worry it wasn't correctly
> flushing files, parking heads etc.)
I always did sync 3 times before bye. It can't hurt.
bye will park the heads on a PERQ1 (or 1A), but puts them in totally the
wrong place on later machines (!).
> (I seriously love that hard disk - it's got a wonderful backyard-engineering
> made-from-washing-machine-parts feel to it :-)
It is rather fun. I assume you know to lock the positioner and the
spindle before moving the machine.
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