; READSW.ASM
; READ SWITCH CONNECTED TO DIGITAL INPUT 1 AND DISPLAY ON OR OFF STATUS
	ORG	8000H		;MUST ALWAYS BE ORG'ED AT 8000H FOR SBC-1
READSW:	CLR	C		;(C3 HEX) NEEDED ONLY IF USING AUTOBOOT
REPEAT:	CALL	4BH		;IOSCAN ROUTINE IN JUMP TABLE
	MOV	A,21H		;21H IS IO1-8
	ANL	A,#1		;LOOK ONLY AT BIT 0 WHICH IS IO1
	ADD	A,#30H		;ADD ASCII CHARACTER OFFSET TO MAKE IT 0 OR 1
	CALL	3CH		;DISPLAY CHARACTER ROUTINE IN JUMP TABLE
	JMP	REPEAT		;KEEP READING AND DISPLAYING
	END			;NEEDED BY MANY ASSEMBLER PROGRAMS