My New Missile Command has a Few Issues (trackball, audio)
http://forums.arcade-museum.com/showthread.php?t=377083
I posted about my Missile Command above. I figured I should move the technical discussion here to get some help.
So since I last posted in that thread I removed the Super Missile Attack add on PCB and I was able to get into the test mode and it passes all tests.
There was an issue with the video being inverted vertically. The yoke connector was connected normally but I decided to flip the vertical yoke connectors and that has fixed that issue so for now.
My remaining issues are:
-no audio
-trackball not working
#1 No audio
I am going to see if I can get a hold of a Pokey chip to swap in for the audio to see if that fixes it. One thing to note is that when I turn up the speaker volume there is a hum.
#2 Track Ball not working
For the trackball I can't find too much info other than one thread that stated I could try replacing the 74LS157 at D9. I have a parts board with some HD74LS157P. Would these work?
I noticed that in test mode when I press player 2 start, the cursor moves to the left a bit... not sure if that's normal.
If anyone has any suggestions I would welcome them! Thanks
http://forums.arcade-museum.com/showthread.php?t=377083
I posted about my Missile Command above. I figured I should move the technical discussion here to get some help.
So since I last posted in that thread I removed the Super Missile Attack add on PCB and I was able to get into the test mode and it passes all tests.
There was an issue with the video being inverted vertically. The yoke connector was connected normally but I decided to flip the vertical yoke connectors and that has fixed that issue so for now.
My remaining issues are:
-no audio
-trackball not working
#1 No audio
I am going to see if I can get a hold of a Pokey chip to swap in for the audio to see if that fixes it. One thing to note is that when I turn up the speaker volume there is a hum.
#2 Track Ball not working
For the trackball I can't find too much info other than one thread that stated I could try replacing the 74LS157 at D9. I have a parts board with some HD74LS157P. Would these work?
I noticed that in test mode when I press player 2 start, the cursor moves to the left a bit... not sure if that's normal.
If anyone has any suggestions I would welcome them! Thanks
