Technical details of Display out [PC98]
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.
Pinout
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 | |
2 | GND | |
3 | CLOCK | |
4 | -HSYNC | |
5 | -VSYNC | |
6 | R | |
7 | G | |
8 | B |
Video signal timing (Analog RGB)
Normal mode 640x200 / 15kHz / Non-interlaced
- Pixel Clock: 14.31818 MHz
- H Freq: 62.58 us (15.98 kHz)
- H Front Porch: 4.47 us (64 Pixels)
- H Sync: 4.47 us (64 Pixels)
- H Back Porch: 8.94 us (128 Pixels)
- V Freq: 16.33 ms (61.23 Hz)
- V Front Porch: 0.94 ms (15 Lines)
- V Sync: 0.50 ms (8 Lines)
- V Back Porch: 2.38 ms (38 Lines)
Normal mode 640x400 / 24kHz / Non-interlaced
- Pixel Clock: 21.0526 MHz
- H Freq: 40.28 us (24.83 kHz)
- H Front Porch: 3.8 us (80 Pixels)
- H Sync: 3.04 us (64 Pixels)
- H Back Porch: 3.04 us (64 Pixels)
- V Freq: 17.72 ms (56.42 Hz)
- V Front Porch: 0.28 ms (7 Lines)
- V Sync: 0.32 ms (8 Lines)
- V Back Porch: 1.01 ms (25 Lines)
Normal mode 640x400 / 31kHz / Non-interlaced
- Pixel Clock:25.175 MHz
- H Freq: 31.78 us (31.47 kHz)
- H Front Porch: 0.58 us (14 Pixels)
- H Sync: 2.54 us (64 Pixels)
- H Back Porch: 3.24 us (82 Pixels)
- V Freq: 14.28 ms (70.05 Hz)
- V Front Porch: 0.41 ms (13 Lines)
- V Sync: 0.064 ms (2 Lines)
- V Back Porch: 1.09 ms (35 Lines)