Technical details of Display out [PC98]

PC98 Display connectort types
Most PC-9801 desktop models have a DA-15 connector, which uses the same analog video signal format with the VGA. It can be converted to DE-15 (VGA) connector with an adapter (Sanwa-supply AD-D15NE and etc.). However, the video mode usually uses 640 x 400 pixels and 24 kHz horizontal sync frequency that is not supported by most standard PC monitors. At present, some Japanese LCD monitors still support it, Century, Iiyama, IO-DATA and NEC.

If you use PC-9821 models (include PC-9801B* models; except PC-9821 model S1 and S2), you can switch its horizontal frequency to 31 kHz that is commonly used on VGA monitors. To switch the horizontal frequency to 31 kHz, hold-down GRPH key and "2" key (above W key) when you turn on the PC-98. To switch back to 24 kHz, hold-down GRPH + 1. It will solve the "out of range" error, but not all monitors can display the screen correctly.


DA15 "Analog RGB"


  Name Description
Pin 1 AR Analog Red
Pin 2 GND Ground
Pin 3 AG Analog Green
Pin 4 GND Ground
Pin 5 AB Analog Blue
Pin 6 GND Ground
Pin 7 YS High Level (RGB selected)
Pin 8 GND Ground
Pin 9 SYNC Composite Sync
Pin 10 AUDIOL Left Audio Output
Pin 11 AUDIOR Right Audio Output
Pin 12 GND Ground
Pin 13 AV Switch Audio/Video Signal
Pin 14 -HSYNC Horizontal Sync(N)
Pin 15 -VSYNC Vertical Sync(N)

Not all machines support the sound output from pin 10 and pin 11.

DIN8 "Digital RGB"

Pin Name Pin Connection
1 +12V
6 R
7 G
8 B

Video signal timing (Analog RGB)

Time chart of PC9801 CRT output signal

Normal mode 640x200 / 15kHz / Non-interlaced

Normal mode 640x400 / 24kHz / Non-interlaced

Normal mode 640x400 / 31kHz / Non-interlaced

inserted by FC2 system