Use for A4000TX (*) or PC that can output TV frequencies.
(*) wire fused power to vga socket
I think the 24 pin header on the A4000TX MB has all the signals, but VGA doesn't have a composite sync.
1. RGB levels are wired straight through.
2. Scart composite sync is combined from VGA horisontal and vertical sync using IC.
3. For SCART TV:s, "choose 4:3" signal is above 5 volts using a switched capacitor voltage booster.
4. For audio connection there is a 3.5mm jack.
5. Place for edid 24c02 for pc:s
6. 74HCT86 current output will be overloaded to drive TV's 75 ohm termination. The output resistor may be around 300 ohms.
You would need a male to female vga cable instead of the regular male to male vga cable, with +5V pin 9 connected, instead of being "keyed". If you plug the adapter straight to motherboard socket, the adapter and scart cable would weigh down the motherboard connector.
info in old thread
Last edited:
