Cartridge self-checking

From samsho4, done for all 4 banks in $200000~$2FFFFF:

move	#$0FFF,d7		;Number of times to test until error LAB_0057: move	#$0001,$2FFFF0		;Set P bank 1 cmpi	#$0001,$2FFFF0		;Check if ($2FFFF0) = 1 beq	LAB_0058		;Pass dbf	d7,LAB_0057		;Or loop move	#$0048,EXT_0574		;Fail move.b	#$FF,2066(a5)		;Set RAM jmp	EXT_01A0		;Write "WARNING BANK ERROR" and lock LAB_0058:

Also see Slot check security.