Composite video to vga converter schematic

Composite video to vga converter schematic install#

The potentiometers are installed on R, G, B and Composite video lines to adjust the signal levels. The wire should be connected to power for 4FSC mode (14,3 and 17,7 mHz) or to be connected to the ground for the FSC mode (3,5 and 4,5 mHz). For AD724 you will need to solder a wire to AD72x chip's pin 12 (Select).

Composite video to vga converter schematic install#

For AD725 you can install an optional Chroma filter. The board is designed to support both AD724 and AD725 chips. I will order several circuit boards for the convertor soon and the next prototype will be assembled on proper board. Be advised that using such pen is recommended only in properly ventilated areas as some gas is emitted when you solder the wire. Seems to work just fine as long as your soldering iron's temperature is above 400 C. For making connections between components I used the 'wiring pen' for the first time. So I decided to use the good old EL1881 chip in a DIP case instead. And due to the lack of the oscilloscope I could not diagnose the problem. The original plan was to use the EL1883 chip to split composite signals, but this failed for unknown reason. You can see the photos of the assembling process as well as the future circuit board pictures here: The Atari ST 1040, Commodore C64 and C64C, Sinclair ZX Spectrum +3 will be tested next - as soon as I make the special cables for them. I tested the converter with Yamaha YIS805 and YIS503, Panasonic FS-A1, Sony F1-XV and Amiga 500. The pinout for the VGA connector matches the real VGA's pinout for convenience. In order to connect a vintage computer to the converter, you have to make a special cable from computer's RGB port to the male VGA connector. The standard 15-pin VGA female connectors are used for input, the output has RCA and S-Video connectors. There's a switch that allows to chose either composite or separate sync signals. The quality of S-Video output is indeed great, PAL and NTSC seems to work correctly, both sync signal types are supported. I called this device 'Zefisha' (don't ask why and what this means). So, the prototype based on AD724 chip is now ready and is working fine. The quality of composite video is acceptable, but nothing compared to S-Video. The output from such converter is a high quality S-Video signal, that can be easily converted to VGA with a cheap 15 euro Chinese-made Video-to-VGA converter. My idea is to create a universal converter that supports PAL and NTSC and that could be used for any vintage computer that has R, G, B and either composite or separate (horizontal+vertical) synchronization signals. It's impossible to connect most of MSX computers to such converter without splitting the synchronization signal first. However, most of them are made for specific hardware, for example for Amiga. There are plenty of such projects on Internet. The idea of creating a converter for connecting vintage computers to modern VGA monitors is not new.