PSone lcd screen (pal) modded to accept arcade signals.

[Jess--]

While I was working away from home over the summer I was lucky enough to obtain a load of jamma boards in unknown states, so I started building up a jamma test rig, PSU monitor mini control panel etc, however I found it to be far too bulky due to the monitor (14" hantarex).

so I started thinking about hacking one of my PSone screens to accept arcade signals, (R G B & C Sync) however this proved fruitless to start with due to my screens only accepting PAL input which caused lots of rolling screens.

after a lot of messing around trying to rebuild the entire sync circuit around the input chip used by the screen I realised that no matter how I reconfigured the chip the screen itself was still only ever syncing to pal frequencies.

once I realised this I turned my attention to the chip handling the output to the screen (after all the processing circuits) chip No MN5814-A
Cutting the track to Pin 46 throws this chip into ntsc mode which so far is displaying all of my arcade boards without any rolling.

I still have one issue where the top 3% of the screen is displayed at the bottom although I hope to resolve this over the next couple of days.

Pictures below.
(yes its tekken 3, and please excuse the reflection of the camera flash)