prog8/lib/il65lib.ill

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2017-12-30 12:34:52 +00:00
; IL65 internal library routines
;
; Written by Irmen de Jong (irmen@razorvine.net)
; License: GNU GPL 3.0, see LICENSE
;
; indent format: TABS, size=8
output raw
~ il65_lib_zp {
; note: separate block so the 64tass assembler can remove this when no zp restore is required
asm {
; ---- store the Zeropage in a backup area
save_zeropage
sei
ldx #2
- lda $00,x
sta zp_backup-2,x
inx
bne -
rts
restore_zeropage
php
pha
txa
pha
sei
ldx #2
- lda zp_backup-2,x
sta $00,x
inx
bne -
cli
pla
tax
pla
plp
rts
zp_backup .fill 254, 0
}
}
~ il65_lib {
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; note: the following ZP scratch registers must be the same as in c64lib
memory .byte SCRATCH_ZP1 = $02 ; scratch register #1 in ZP
memory .byte SCRATCH_ZP2 = $03 ; scratch register #2 in ZP
memory .word SCRATCH_ZPWORD1 = $fb ; scratch word in ZP ($fb/$fc)
memory .word SCRATCH_ZPWORD2 = $fd ; scratch word in ZP ($fd/$fe)
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asm {
; ---- jmp (indirect) routines for register pairs containing the indirect address
jsr_indirect_nozpuse_AX
sta jsr_indirect_tmp
stx jsr_indirect_tmp+1
jmp (jsr_indirect_tmp)
jsr_indirect_nozpuse_AY
sta jsr_indirect_tmp
sty jsr_indirect_tmp+1
jmp (jsr_indirect_tmp)
jsr_indirect_nozpuse_XY
stx jsr_indirect_tmp
sty jsr_indirect_tmp+1
jmp (jsr_indirect_tmp)
jsr_indirect_tmp
.byte 0, 0
jsr_indirect_AX
sta SCRATCH_ZP1
stx SCRATCH_ZP2
jmp (SCRATCH_ZP1)
jsr_indirect_AY
sta SCRATCH_ZP1
sty SCRATCH_ZP2
jmp (SCRATCH_ZP1)
jsr_indirect_XY
stx SCRATCH_ZP1
sty SCRATCH_ZP2
jmp (SCRATCH_ZP1)
}
}