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Apple II plus video issue

Posted by: bibilit on 2020-06-17 18:35:40 Looking for help, i have an Apple II at home, many issues, including bad Ram and bad Rom...still have an issue (ram and Rom was replaced already) probably in the video or ram neighborhood as both are connected, the issue is visible because a portion of the video is displayed twice.  See picture where the same first line is displayed twice (remaining part of the display was the Rom issue now fixed) unable to boot any disk also

Posted by: bibilit on 2020-06-20 00:05:12 So, found the issue, my hunch was right, both in the video generation circuit and ram location.  With the help of the Apple II reference book I located the bad 74LS283 chip.  The Apple is no longer displaying the video issue and booting fine.

Posted by: slomacuser on 2020-06-20 00:20:22 Nice job Bibilit 🙂  I have also ][ europlus, but there are not all keys working on keyboard.. have to check and clean someday. What is that Machine identification software?

Posted by: bibilit on 2020-06-20 00:41:49 Hi  MECC inspector.  I still have your parcel, now that the Covid issue is under control I will send it back.  Concerning your keyboard, the connector is weak, any broken pin ?

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