Disk ][ Analogue Board Trimmers

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Disk ][ Analogue Board Trimmers

On the Disk ][ Analogue Board (691-92001), there are two trimmers, factory set and sealed with orange/yellow wax. On one of the drives that I have, one of these has been broken free. 


The service books do not and never have mentioned adjusting these. Does anyone recall what each trimmer does, and how to calibrate them?

Last seen: 1 month 2 weeks ago
Joined: Jun 5 2008 - 07:26
Posts: 475
One of them is peak hold

One of them is peak hold/detection timing.  There is a bit on this one in Apple II restoration pages and a reference to  Jim Sather's book, "Understanding the Apple II".




The other may be disk rotational speed adjust, but it's on a different board, so I'm not sure if that is the one that you are refering to.


With the right tools, both are fairly easy to tweak.



Mike Willegal




amauget's picture
Last seen: 6 days 11 hours ago
Joined: Jan 3 2011 - 11:34
Posts: 339



The 2 potentiometers are described in the Disk II trechnical procedures  pages 46 & 47.




Apple II forever

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