RESOLVED: Tempest - bad output on "Y" & scaling issues..
Just got the monitor issue resolved (see here).
EAROM wasn't working (not saving high scores), so after putting several games on the monitor to verify it was solid, I shut down, and powered back to confirm it was indeed still not saving scores.
As fate would have it, my board has now decided to go down - I'm getting this output, consistently - both on the monitor, and on my scope..
As per this post, it sounds like I can connect my scope leads at the first TL082 after the DAC, and before the MC1495L's to see if I get a good (albeit smaller) image. If that image is good, I know the issues are downstream. If they're not, then I'm guessing I'd suspect an issue with the DAC @ D10?
Would this equate to pins 9 & 11 on the 74LS04 @ J11, or should I go with pin 1 off of A11/D11?
All voltages in the area checked out as well... Going to pick up a bunch of TL082's (NTE858M) tomorrow; the one at D/E13 was already socketed/replaced by me when I was originally repairing the board, so easy enough to do a quick swap on it - others are not socketed however. Want to make sure whether I'm likely dealing with MC1495's/TL082's vs. the DAC, since if it's likely the MC1495's, I'll be putting an order in to get a batch from China which will take a while...
Appreciate clarification/insight! Pretty bummed that I finally get the monitor solid, and the boardset (which had been solid for a good while) decides to die immediately afterwards
Just got the monitor issue resolved (see here).
EAROM wasn't working (not saving high scores), so after putting several games on the monitor to verify it was solid, I shut down, and powered back to confirm it was indeed still not saving scores.
As fate would have it, my board has now decided to go down - I'm getting this output, consistently - both on the monitor, and on my scope..
As per this post, it sounds like I can connect my scope leads at the first TL082 after the DAC, and before the MC1495L's to see if I get a good (albeit smaller) image. If that image is good, I know the issues are downstream. If they're not, then I'm guessing I'd suspect an issue with the DAC @ D10?
Would this equate to pins 9 & 11 on the 74LS04 @ J11, or should I go with pin 1 off of A11/D11?
All voltages in the area checked out as well... Going to pick up a bunch of TL082's (NTE858M) tomorrow; the one at D/E13 was already socketed/replaced by me when I was originally repairing the board, so easy enough to do a quick swap on it - others are not socketed however. Want to make sure whether I'm likely dealing with MC1495's/TL082's vs. the DAC, since if it's likely the MC1495's, I'll be putting an order in to get a batch from China which will take a while...
Appreciate clarification/insight! Pretty bummed that I finally get the monitor solid, and the boardset (which had been solid for a good while) decides to die immediately afterwards
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