This schematic is still on DEVELOPMENT state.
if you have ideas or suggestions, please join and discuss them.
This is internal or external circuit and a layout made by me:
This is replacement circuit for sony cxa chips in genesis NTSC console and variety of another RGB consoles. If you want to add for some reason s-video to pal you need to ground pin 1.
Composite sync (CVBS) or Csync input:
Note: This is layout is for older equipment which might not output from VDP H- and Vsync, there for providing sync with Compositesvideosync (CVBS) or Csync alone.
Hsync & Vsync input:
Note: CLK pin is NTSC (or pal) clock signal which is going to sony chip also. Take it from there.
More info can be found here: http://www.cpcwiki.eu/index.php/RGB_SVideo
- AD724 (only available as 16pin soic afaik but practice makes pros and lot's of youtube videos about surface soldering)
- 5*100nF ceramic
- 1*100uF elko 6mm dia
- 4*220uF elko 8mm dia (important bigger dia elko dont fit to mobo design)
- 1*4.7pF ceramic or similar value depeanding on the output if it is good enough. If not change this one to another value.
- 6* 75ohm 1/8 resistors (important board not desinged for 1/4watt resistors but if you put resistors standing they will fit.)
- 1*1N4001 diode
Note: The composite layout is same layout but no vertical sync input.
Board size: 45mm*33mm
1.0 - I changed orginal layout resistor from green to blue as I think it was layout fault in orginal author layout. Please report if the mobo don't work.
For AD724 testing:
Here is layout image for testing AD724 on Solderless board. So you can build the circuit adding Metal pins to Dummy DIP16 pins or use cables and solder them to dummy pins, then attach to solderless board.
PDF added to attachment.