This is a reversed engineered schematic of the MEGACOPY III by TRISYD VIDEO GAMES (C) CARTER 1987, 1988

Dimensions:

Case – 100mm x 50mm x 27mm
PCB – 66mm x 37mm
Cables (4) - 32cm

Parts:

U1 - 74LS157N
U2 - 74LS266N
R1 - 220 Ohms 1/4w
D1 - Green LED
D2 - Red +5V tolerant blinking LED
J1 - POWER/ACTIVE SPST switch input
J10(CON) and J10(DDP) - 9-pin .100"(2.54mm) male header
J11(CON) and J11(DDP) - 8-pin .100"(2.54mm) male header


Flaws and Considerations:

The red LED is a special 5V tolerant blinking variety

VCC of U2 is floating when the active switch 
isn't enabled and is not good practice. This could have
mixed results with different chip manufacturers

J11(CON) to J11(DDP) connection is not used
by the system and not needed

THIS CIRCUIT HAS NOT BEEN VERIFIED AND USE AT YOUR OWN RISK


John Lundy 4/2021