Playstation 2 – Video Adaptor
Recently I bought a Playstation 2 development kit (the cheaper Linux version) for use at university. However, although it works correctly on a television, when I tried to use it on my TFT monitor, everything was green.
After a bit of research, I found out that the problem is known as Sync-on-Green – additional information is transmitted down the green channel for synchronization.
I did some googling and found an integrated circuit designed for separating the synchronization information, a DIL called EL1881. The only place I could find them though was on the American eBay, so I decided to buy a few incase I blew any of them up.
When it arrived I adapted the documentation and managed to create an adapter that took in the PS2 VGA socket and outputed it through another VGA socket. Between the sockets, the chip would be used to extract the synchronization information and output it through pin 13 and 14 on the output VGA.
I’ve put a diagram of the circuit for those interested in making their own. Most of the connection do not need to be soldered between plugs, and there are two new connections to be added for the output for the sync information.
You may have noticed I had added a 0.1uF capacitor over a 620k resister on PIN 6 of the chip (Reset). This a chroma filter to increase the propagation delay from the composite input to the outputs. You could also have it before the capacitor connected to PIN 2 with a slight modification. See the documentation for more info.
The hardest part of all this was soldering the wires to the VGA adapter – its hard to solder in a confined environment, most of the time I melted the back of the socket.
I think the end result looks very clean though, if only it didn’t require an external 5V power supply to the chip. In the end I modified the additional wires to instead use the USB ports on the Playstation 2.
However I believe on the PS2 output (that other side of the PS2 to VGA cable), there is power on PIN 10, however I did not have any spare ones to play with, and it is not forwarded along the cable unfortunately.