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6502bench/SourceGen/Examples/Tutorial/Source/Tutorial1.S
Andy McFadden 4537f24958 Rework tutorial for changes in v1.8
Biggest changes were to the address region handling in Tutorial1
and the use of StdInline.cs for the inline strings in Tutorial4.

Also, fixed the off-by-one error in Tutorial1.
2021-11-14 09:02:53 -08:00

62 lines
1.3 KiB
ArmAsm

; Copyright 2018 faddenSoft. All Rights Reserved.
; See the LICENSE.txt file for distribution terms (Apache 2.0).
;
; Assembler: Merlin 32
INPUT equ $3000
OUTPUT equ $0400
org $1000
ldy #END-AFTER-1
copy lda BEFORE,y
sta AFTER,y
dey
bpl copy
bmi done
dfb $00
stuff asc 'hello!'
done jmp AFTER
BEFORE
org $2000
AFTER
lda INPUT ;expecting 0-3
cmp #4
blt :valid
lda #4 ;error message
:valid asl A
tax
lda stringtab,x ;set load to address
sta _load+1
lda stringtab+1,x
sta _load+2
ldy #12 ;fixed-width strings
_load lda $0000,y ;self-modifying code
ora #$80
sta OUTPUT,y
dey
bpl _load
rts
stringtab
dw string0
dw string1
dw string2
dw string3
dw stringX
dfb $00
string0 asc 'string zero '
string1 asc 'string one '
string2 asc 'string two '
string3 asc 'string three '
stringX asc 'invalid index'
END