Random number between 0 and 9

rnd.asm

*=$0801
	!word	$080C			; Pointer to next BASIC line
	!word	$000A			; Line number $000A = 10
	!byte	$9E			; SYS BASIC token
	!pet	" $810",0		; Address where ASM starts
	!word	$0000			; EOF BASIC program
*=$0810

CHROUT	= $FFD2
SEED	= $9F64			; VIA timer low-byte

main:
	lda	SEED
	and	#$0F		; 10 is max so use $0F to get down to 15
	cmp	#10
	bcs	main		; Try again if .A is >= 10
	ora	#$30		; OR with $30 to get petscii character
	jsr	CHROUT		; Print character
	lda	#' '		; Print a space
	jsr	CHROUT
	jmp	main
	rts