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cc65/libsrc/cx16/vset.s
Greg King 9fa90e2265 Added VERA peek() and poke() to the cx16 library.
They simplify C programs' direct access to VERA's internal address space.
2019-10-24 05:15:42 -04:00

21 lines
529 B
ArmAsm

;
; 2019-10-22, Greg King
;
; Set the __far__ address that VERA will use for data access.
; This is a support function for the fastcall functions vpeek() and vpoke().
;
.export vset
.importzp sreg
.include "cx16.inc"
vset: ldy sreg
sei ; don't let interrupt handlers interfere
stz VERA::CTRL ; set address for VERA's data port zero
sta VERA::ADDR
stx VERA::ADDR+1
sty VERA::ADDR+2
rts