verif_checksum:

		; verify main ROM

		ldx	off_9000
		clra
		clrb

loop_9D20:			
		addb	,x
		adca	#0
		leax	1,x
		bne	loop_9D20

		tfr	d, u
		cmpd	word_9002
		lbne	do_ROM_checksum_error_handler

		; verify pages

		ldx	#page_register_tbl

loop_9D35:
		ldb	,x
		cmpb	#$FF
		beq	exit_9D45
		pshs	x
		bsr	verif_checksum_page ; adress 0x9D48
		puls	x
		leax	1,x
		bra	loop_9D35


exit_9D45:
		tfr	u, d
		rts


page_register_tbl:
		fcb  8
		fcb  9
		fcb  $A
		fcb  $B
		fcb  $C
		fcb  $D
		fcb  $E
		fcb  $F
		fcb $FF