Date : Sat, 09 Nov 1991 15:47:26 GMT
From : mcsun!uknet!jet!dba@uunet.uu.net (dennis armstrong)
Subject: Xerox 820-1 on 50 HZ power
To: gentges@ITD.NRL.NAVY.MIL
Subject: Re: Xerox 820-1 on 50 HZ power
Newsgroups: comp.os.cpm
References: <9111070105.AA05295@itd.nrl.navy.mil>
In comp.os.cpm you write:
>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.
For 240/220 volt 50Hz supply Shugart sold drives with 240v motors.
A transformer can change the voltage to 110v (dont forget the DC
power supply input voltage requires changing as well!)
>If we do not change the motor spindle, will the machines still work?
Yes but at a non standard disk drive speed.
>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.
The problem is that all software cannot be read if supplyed on disks
sourced from US sources (including utilitys and the boot disk!!)
>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?
no the timing components expect data from the standard 360Hz disk speed.
>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?
They will then not be able to transfer data on 8 inch floppys to any other
systems. They should be able to machine a new pulley and adjust the
mounting of the drive motor to allow for the different belt size.
>Any experience on this rather obscure matter would be appreciated. Note
>that the Xerox manual does not mention AC power specs :-<
Please email if you require further assistance, I have the Shugart manuals.
I can offer free to a good home two new 110v motors, 60hz pulleys and belts.
You pay shipping from UK.
Keep CP/Ming
Dennis Armstrong
--
__. .__________________________. ._____________________________________________
__| |___. .__. ._____. .____| |_____________________________________________
| | | | | | Dennis Armstrong, CODAS division
| | | |___. | | Joint European Torus
| | | :___| | | Abingdon, Oxfordshire, UK
| | | | | | Tel 0235 528822 Ex 4871
|~__' : | `---. | | dba@jet.uk
~-----~ +------+ +--+
- Disclaimer: Please note that the above is a personal view and should not
be construed as an official comment from the JET project.
End of INFO-CPM Digest V91 Issue #185
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