;
.export _set_brk, _reset_brk
+ .destructor _reset_brk
.export _brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
- .import _atexit
.include "atari.inc"
lda oldvec
ora oldvec+1 ; Did we save the vector already?
- bne L1 ; Jump if we installed the handler already
+ bne L1 ; Jump if we installed the handler already
lda VBREAK
sta oldvec
lda VBREAK+1
sta oldvec+1 ; Save the old vector
- lda #<_reset_brk
- ldx #>_reset_brk
- jsr _atexit ; Install an exit handler
-
L1: lda #<brk_handler ; Set the break vector to our routine
sta VBREAK
lda #>brk_handler
; Reset the break vector
.proc _reset_brk
- lda oldvec
- sta VBREAK
- lda oldvec+1
- sta VBREAK+1
- rts
+ lda oldvec
+ ldx oldvec+1
+ beq @L9 ; Jump if vector not installed
+ sta VBREAK
+ stx VBREAK+1
+ lda #$00
+ sta oldvec ; Clear the old vector
+ stx oldvec+1
+@L9: rts
.endproc