Files
super6502/sw/mapper.s
Byron Lathi a15dde0e89 Add memory mapper software interface
Adds functions to read and write mappings, as well as enable and disable
the memory mapper.

This also moves increases the io space by 16 bytes.
2022-04-07 10:33:50 -05:00

33 lines
309 B
ArmAsm

.include "io.inc65"
.importzp sp, sreg
.export _mapper_enable
.export _mapper_read, _mapper_write
.autoimport on
.code
; void mapper_enable(uint8_t en)
_mapper_enable:
sta MM_CTRL
rts
_mapper_read:
phx
tax
lda MM_DATA,x
ldx #$00
rts
_mapper_write:
phx
tax
jsr popa
sta MM_DATA,x
plx
rts