83:Ports:02

Synopsis

Port Number: 02h

Function: ROM and RAM Pager and Memory Map Control

This port controls what page is swapped into the swappable memory range which depends on the current mapping mode.

Always the last value written.

Bits 0 to 2: The lower 3 bits of the desired ROM page (bit 3 can be set through bit 4 of the link port)
Bit 3 controls the memory mapping mode. The default value for this bit is 1.
Bit 4: Unknown, harmless
Bit 5: Unknown, harmless
Bit 6: 0 - the specified ROM page is swapped in, 1 - the RAM page specified by bit 0 swapped in.
Bit 7 controls the memory mapping mode. The default value for this bit is 1.