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Old 06-26-2007, 10:59 PM
Geoff Harrison Geoff Harrison is offline
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Join Date: Feb 2007
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The Altairkit power supplies are switching units instead of the original linear supply, and you're right, they do completely block any 60Hz ripple.

It looks to me, though, like the RTC board could only work off of the system clock in a standard 8800 anyway. The RTC manual says it can get its timing signal from the 2Mhz clock or by picking up a 60Hz signal on the unrectified voltage on bus pin 55, but according to the 8800 manual, pin 55 isn't connected to anything. It is labeled as RTC in the 8800b manual and flagged as a new signal for the 8800b.

Geoff.

Last edited by Geoff Harrison; 06-26-2007 at 11:07 PM.
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