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symon/samples/hello.asm
Seth Morabito 38a4458aff New UI layout, ROM loading, Font selection
- The UI layout has changed, and will likely change again in the future.

- Symon can now re-load ROM images from the File menu, under "Load ROM..."

- Font size can be changed under the "View" menu
2012-12-05 23:19:34 -08:00

32 lines
770 B
NASM

;;
;; Output the string 'Hello, World!'
;;
.alias iobase $8800
.alias iostatus [iobase + 1]
.alias iocmd [iobase + 2]
.alias ioctrl [iobase + 3]
.org $0300
start: cli
lda #$0b
sta iocmd ; Set command status
lda #$1a
sta ioctrl ; 0 stop bits, 8 bit word, 2400 baud
init: ldx #$00 ; Initialize index
loop: lda iostatus
and #$10 ; Is the tx register empty?
beq loop ; No, wait for it to empty
lda string,x ; Otherwise, load the string pointer
beq init ; If the char is 0, re-init
sta iobase ; Otherwise, transmit
inx ; Increment string pointer.
jmp loop ; Repeat write.
string: .byte "Hello, 6502 world! ", 0