3 Jul
2007
3 Jul
'07
1:04 p.m.
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.
-tony