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PC98_Printer_8255 Class Reference

PC-98 Printer 8255 PPI emulation (Intel 8255A device) More...

Inheritance diagram for PC98_Printer_8255:

List of all members.

Public Member Functions

virtual uint8_t inPortB (void) const
 Called by 8255 emulation to latch from port B pins.

Detailed Description

PC-98 Printer 8255 PPI emulation (Intel 8255A device)


         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 1685 of file keyboard.cpp.

The documentation for this class was generated from the following file: