UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Non-working Commodore PET 3016

ScottishColin · 26th Feb 2021, 1:18 pm

Every day a school day - I was triggering and didn't know it. Thanks for the information. I have set the trigger to 1.38V on CH0 (nearest I can get to 1.4V). Scope probes are set at 10x.

I have done another reading of Pin 20 UD9 and Pin 2 UD9 (I can't sensibly get to the 6502 pins) and attch.

There's two pages.

For the second reading, I set the scope to 20us but that doesn't give me any reading at all on pin 20 of UD9. It does give me an intermittent reading of Pin2 of UE9 as attached - this comes and goes, but it's there.

Is there any good reason I can't get anything at 20us off the PROMs?

https://drive.google.com/file/d/1o-E...ew?usp=sharing

Colin.

26th Feb 2021, 1:18 pm	#678
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,803	Re: Non-working Commodore PET 3016 Every day a school day - I was triggering and didn't know it. Thanks for the information. I have set the trigger to 1.38V on CH0 (nearest I can get to 1.4V). Scope probes are set at 10x. I have done another reading of Pin 20 UD9 and Pin 2 UD9 (I can't sensibly get to the 6502 pins) and attch. There's two pages. For the second reading, I set the scope to 20us but that doesn't give me any reading at all on pin 20 of UD9. It does give me an intermittent reading of Pin2 of UE9 as attached - this comes and goes, but it's there. Is there any good reason I can't get anything at 20us off the PROMs? https://drive.google.com/file/d/1o-E...ew?usp=sharing Colin.