; Update to LSDOS 6.3.1 2022-09-16 dpm

		SCOPE

; Device byte I/O handler.
; C => Byte/character if PUT or CTL.
; DE => Device control block.
			
zCTL		PUSH	BC
		LD	B,4		;Bit 2, CTL
		JR	IOBGN
zKEY		CALL	zKBD		;Scan the keyboard
		RET	Z		;Ret if key available
		OR	A		;Return if error
		JR	Z,zKEY
		RET

