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6502bench/SourceGen/Examples/Tutorial/Source/Tutorial1.S
Andy McFadden 4b46b78e34 Rearrange the tutorial files
Copied the extension script tutorial files out of the Scripts
directory and into the Tutorial directory.  This makes more sense,
and makes it possible to expand the script sample without altering
the tutorial.

Reverted the Scripts sample to be an actual sample, rather than a
tutorial.

Renumbered the last two tutorials and added them to the ToC.  This
gives them actual numbers rather than treating them as add-ons to
the advanced tutorial.

Moved the source files for the tutorial binaries into a subdirectory
to reduce clutter.

This does mean we have two separate copies of the inline string
sample plugins, but that's an artifact of our attempts at security.
2019-10-30 09:49:11 -07:00

63 lines
1.2 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
copy lda BEFORE,y
sta AFTER,y
dey
bmi done
bpl copy
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