PC-98 Printer 8255 PPI emulation (Intel 8255A device) More...
Public Member Functions | |
| virtual uint8_t | inPortB (void) const |
| Called by 8255 emulation to latch from port B pins. | |
PC-98 Printer 8255 PPI emulation (Intel 8255A device)
TODO...
This PPI is connected to I/O ports 0x40-0x46 even.
- 0x40 Port A
- 0x42 Port B
- 0x44 Port C
- 0x46 control/mode
Except on super high resolution
display units, Port B is also used to
return some dip switches and system configuration,
with only one bit to indicate printer status.
This PPI is connected to:
- Port A (out): Output to printer
- Port B (in): PC-98 model, system clock (8 or 5/10MHz),
HGC graphics extension, printer busy,
V30/V33 vs Intel x86 CPU, CPU HA/LT sys type,
VF flag (?)
- Port C (out): Strobe, IR8 interrupt enable, 287/387 reset(?) Definition at line 1697 of file keyboard.cpp.
1.8.0