16 May
2007
16 May
'07
2:10 a.m.
That's nice to know - FWICT my modified YE Data
drive is running at about
290RPM instead of 300 (based on the index pulse timing). Now I don't have to
try and figure out how to speed it up by another 10RPM :)
That said, the drive motor appears to be crystal-locked, so increasing the RPM
might be a little difficult anyway.
Thats odd - I have a number of drives that are crystal controlled and non-
adjustable, and they are all "bang on" 300 or 360 rpm ... Thats a pretty
big error.
BTW Dave, thanks for the page on modifying 5.25"
drives for 300RPM - the
method you mentioned worked like a charm. I'd post the wire colours for the
high/low speed switch, but the drive's downstairs. Basically, there's one line
that's always at +5.0V, one that's always +12.0V, one that's on/off depending
on the motor's state (on or off) and one that sits at around 4V. Ground the 4V
line at the motor controller board (and disconnect said wire from the drive
controller/head amp board first!) to get 300RPM.
The exact wire colors very from drive to drive which is why I describe the
method (pretty much what you describe above) to find the right one...
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html