Re: 8050 which will write but not format

From: Mike Naberezny <>
Date: Mon, 03 Dec 2012 10:38:20 -0800
Message-ID: <>
Hi Rob,

On 11/30/12 4:17 PM, Rob Clarke wrote:
> In a nutshell, drive 1 works 100%, drive 0 will read and write but not format.
> It usually stops on track 1 with a #21 read error but occasionally will go as
> far as track 3 or 4. If I swap the mechanisms, the problem stays with drive1.
> This implies a problem in the analogue board (micropolis pcb #8050006)

You might want to read an article called "Help for 8050 Speed Problems" in the 
June 1991 issue of Northwest Computer News.  You can download it here:

It describes the operation of the tach circuit and suggests a few component 
replacements to improve its reliability.


Mike Naberezny (

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Received on 2012-12-03 19:00:09

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