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;
; Ullrich von Bassewitz, 14.09.2001
;
.export _peekbsys, _peekwsys
.importzp ptr1
.include "cbm510.inc"
; ------------------------------------------------------------------------
; unsigned char __fastcall__ peekbsys (unsigned addr);
.proc _peekbsys
sta ptr1 ; Store argument pointer
stx ptr1+1
ldx IndReg
lda #$0F
sta IndReg
ldy #$00
lda (ptr1),y
stx IndReg
ldx #$00 ; Extend to word
rts
.endproc
; ------------------------------------------------------------------------
; unsigned __fastcall__ peekwsys (unsigned addr);
.proc _peekwsys
sta ptr1 ; Store argument pointer
stx ptr1+1
ldx IndReg
lda #$0F
sta IndReg
ldy #$00
lda (ptr1),y ; Get low byte
pha
iny
lda (ptr1),y ; Get high byte
stx IndReg
tax ; High byte -> X
pla ; Low byte -> A
rts
.endproc
|
