C64 hello world. Assemble with `dasm`. https://twitter.com/dgellow/status/681142655213027328

helloworld.asm

        processor 6502          ; define processor family for dasm
        org $C000               ; memory location for our code

clear = $e544                   ; clear screen
drawchar = $ffd2                ; draw value in regA

main:
        jsr clear
        jsr drawmsg

return:
        rts

msg:
        .byte "HELLO YOU#"
        rts

drawmsg:
        ldx #0                  ; regX keeps msg index
        jsr drawmsghelper
        rts

drawmsghelper:
        lda msg,x
        cmp #35                 ; test regA with char '#'
        beq return

        jsr drawchar
        inx
        jmp drawmsghelper