Apple II Display issue

You need to adjust the horizontal hold of your monitor. This also happens if the level of the video signal is too low, which is regulated by the potentiometer right next to the RCA video connector inside the Apple II.

Could also be due to VSYNC issue (no vertical serrations) if this is a REV 0 board (lucky you!).

tt0ny wrote:

This is a Rev4 board. I have already tried the horizontal hold on the mainboard and the monitor, but it didn't help. MIke's page show this error but it only applies to the Rev0 board, doesn't it?

This is true. However, the VSYNC issue was "fixed" again in the REV 7 motherboard (and done correctly this time). So you might need to compare how that change was made. If you're not handy (or willing) to modify your motherboard, then your only other choice would be to find a different monitor that doesn't show this problem. Or get a newer motherboard!

Another possible fix would be to run the Apple video through another device to clean up the sync. Try using the video IN and OUT of a VCR for example.

What is the make and model of the monitor you are using? Also is your Apple II outputing NTSC or PAL?

I also live in Europe. Check to see of your Apple II has been converted to NTSC. I have a similar situation with one of my green monitors with my Apple II+ after I converted it to NTSC:

Green monitor AppleII.JPG

There is no problem with the same Apple II+ on a different monitor:

White monitor AppleII.JPG

There is also no problem on the same monitor with my Apple II+ clone (Pravetz 82) which is still on PAL:

Green monitor Pravetz.JPG

This happens on only one of the 7 CRT monitors that I have.