Monitor Help

[jminkema]

I have a old pacman cocktail the i am trying to get to work with arcadevga and j-pac. But when the computer boot up the picture is scrambled.

on a side note it seems like all Horiz PCB come out scrambled while Vert PCB sync fine.

Is there anyway for the arcadevga/j-pac to emulate a vert pcb.

thanks

[tom61]

The monitor's chassis should be all one PCB, make sure you haven't confused part of the Pac-Man boardset as being part of the monitor (I remember there being alot of boards)

[jminkema]

The cabnit has been converted to jamma,  I have two vertical jamma games that play fine.  But any horizional game is scrambled.  All the games have been tested in another cabnit and work great.

I would think that if I still had pacman pcb wired in the vertical games would not work.

[AndyWarne]

The vertical games operate at a lower vertical frequency (50Hz) than the horizontals (60Hz) because more time is needed to scan all those extra lines and keep within the 15Khz horizontal scan range.
So you might need to adjust the vert hold control. It should be possible to find a setting which locks at both frequencies.

Andy

[jminkema]

I have adjusted the v-hold all the way one way to all the way the other.  What is really trobling me is i jave seen monitors not synce before.  usally you can see the general idea of the picture.  With all horizional games i don't get any collor just white.  there is just a huge mess of white dots and line.  It does not look anything like the picture should.  on top of that the picture slowly rolls the than starts to roll faster.  

any ideas would help?

are there any monitors that can only sync vertical?

Could my cocktail be missing any jamma wires that would caues only vert games to sync?