Garbled display when certain keys are pressed.
Posted: Fri Dec 13, 2019 5:35 pm
I just got a zeddy and it has a weird issue.
If I press some of the keys it works fine but others cause the screen to become garbled. The computer has not hung however and mostly continues to work!
10. So far so good.
Press REM and this!
Press return and the line goes to the top of the screen as expected!
If I press NEW and enter I get the cursor back.
Not all the keys cause this issue, for example PLOT is ok.
If I plug in an external keyboard it does the same.
I plugged in my ‘spand and it loaded and displayed garbled stuff which should have been the menu. I could see blobs of black moving up and down when pressing the arrow keys.
All of the chips are socketed so I will change them to see which one is dodgy but any guesses at this stage? I’m guessing (hoping) ROM.
If I press some of the keys it works fine but others cause the screen to become garbled. The computer has not hung however and mostly continues to work!
10. So far so good.
Press REM and this!
Press return and the line goes to the top of the screen as expected!
If I press NEW and enter I get the cursor back.
Not all the keys cause this issue, for example PLOT is ok.
If I plug in an external keyboard it does the same.
I plugged in my ‘spand and it loaded and displayed garbled stuff which should have been the menu. I could see blobs of black moving up and down when pressing the arrow keys.
All of the chips are socketed so I will change them to see which one is dodgy but any guesses at this stage? I’m guessing (hoping) ROM.