Date   : Wed, 06 Nov 1991 20:05:51 EST
From   : gentges@itd.nrl.navy.mil (Frank Gentges)
Subject: Xerox 820-1 on 50 HZ power

I have several Xerox 820-1 computers I want to send over to the Russian
republic for their use.  They can convert their voltage to 120 volts but
the power line frequency is 50 hz.  These computers have the Shugart
800 drives.  According to the Shugart manual, they will run on 50 Hz
but need a different motor pulley to get the spindle speed corrected.

If we do not change the motor spindle, will the machines still work?

As I see it, if you were to format and use the disk from the beginning
on 50 hz, all you would do would be to have the density on the disk go
up 6/5 ths and the gap between the start of a track and the end would
be longer.  This does not seem to be a problem.

If you put a disk that has been formatted at 60 hz and data put on at
60 hz. into a machine running on 50 hz, will the disk controller chip
deal with the 5/6 ths slower data rate?

Once over there, the users will have little need to move the disks back
to a 60 hz machine.  Can we do a one time transfer?

Any experience on this rather obscure matter would be appreciated.  Note
that the Xerox manual does not mention AC power specs :-< 

       Frank Gentges
       gentges@itd.nrl.navy.mil


End of INFO-CPM Digest V91 Issue #184
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