Table of Contents

Japanese RGB-15 Connector

This connector is the standard for many pre-DOS/V (IBM compatible) computers in Japan. The PC-9801, X68000 and FM Towns all used this pinout, or similar variants of it.

Pay attention to the differences, they are important! Specifically, watch the Ys line. This is a 5V signal from the machine that tells the monitor a computer is actively sending video. Without this signal many monitors will not attempt to show anything, and my NEC monitor simply goes into standby. Since many devices don't include 5V (for example, VGA) you may have to add this yourself. I wired mine to a USB connector, and plug that in to any USB device to activate the monitor.

NOTE the numbers are usually visible on the connector itself. If you're looking at the business end of the female connector, pin 1 is on the right. On a male connector it's on the left.

X68000

PinFunctionPinFunction
1 Red 9 NC
2 Ground 10 Audio L
3 Green 11 Audio R
4 Ground 12 Ground
5 Blue 13 NC
6 Ground 14 H-Sync
7 Ys 15 V-Sync
8 Ground

PC 9801

The PC-9801 connector is nearly the same as the X68000. The differences are very minor: pins 9 and 13 are used for the 9801, but are not connected on the X68000.

PinFunctionPinFunction
1 Red 9 Ys
2 Ground 10 AV Control
3 Green 11 Mode
4 Ground 12 Ground
5 Blue 13 Dot Clock
6 Ground 14 H-Sync
7 Ys 15 V-Sync
8 Ground

FM Towns

PinFunctionPinFunction
1 Red 9 Ys
2 Ground 10 AV Control
3 Green 11 Mode
4 Ground 12 Ground
5 Blue 13 Dot Clock
6 Ground 14 H-Sync
7 C-Sync 15 V-Sync
8 Ground

CAVEATS


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