On Tue, 22 Aug 2000, David Williams wrote:
> One of the drives seems to be working fine. The other makes the
> "jackhammer" sound at startup as it positions the head but after
That's the drive being recalibrated. What's actually going on is the
drive head guide thingy is bumping up against the stop. The disk
controller boot code attempts to move the head back 35 or so tracks at
startup. This is to ensure that the head always starts out at track $00.
> that the drive just spins and nothing else ever happens. Any ideas
> on what to check? Not that I don't have plenty of Apple II drives but
> it would be nice to have both these Lobo drives working since that's
> what was used with this system.
Clean the heads. Also, check the drive speed with a program like Copy
][+. It has an option under "VERIFY" to verify the speed of the drive.
You must have a blank disk to do the calibration with because it destroys
track $22. I don't know what the mechanism is to adjust the drive speed
of a Lobo drive. Probably very similar to the Disk ][ which involved
putting the exposed drive spindle disc under an flourescent light and
adjusting until the bars printed on the disc appear to be stationary. I
believe there is an easier method.
The Unidisk or Duodisk drives are much easier to adjust. They have a
micro-screw adjustment pot that's accessible from a small hole on the
underside of the drive.
Sellam International Man of Intrigue and Danger
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Received on Tue Aug 22 2000 - 23:44:16 BST