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Old 5th Mar 2021, 5:29 pm   #802
ScottishColin
Octode
 
Join Date: May 2012
Location: Perth, Scotland
Posts: 1,822
Default Re: Non-working Commodore PET 3016

UH2/2, UG9/3 and UH6/12 give me 1Mhz square waves.

Nothing on UH6/3.

Nothing on UH9/12, 11, 9 or 8

UG9/6 and UH7/9 have the sameas each other - a 'longer' wave at 1Mhz.

Nothing on UH7/12.

Colin.


Quote:
Originally Posted by SiriusHardware View Post
Let's try following the timing chain for a while.

With all ICs inserted as normal, power on, please scope the following IC pins:

UH2 pin 2
UG9 pin 3
UH6 pin 12

You should have the same signal on all three of the above pins. If you don't even have a signal on UH2 pin 2, stop and report back.

Assuming you do, could you then look for further signals on

UH6 pin 3
UH9 pins 12, 9, 8, 11

UG9 pin 6
UH7 pin 9
(Both of the above two should be the same)

UH7 pin 12
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