; ********** INPUT ROUTINE **********
; SCANS KEYBOARD FOR INPUT OF 0 TO 7 OR 8 KEYS, AND 
; IGNORES ALL OTHERS. WAITS FOR KEYPRESS.
; 	ENTRY:	NO PARAMETERS.
;	EXIT:	(A) = 0 TO 7 OR 8 IN BINARY.
;			ALL REGISTERS EXCEPT A ARE SAVED.
; **************************************************

.ORG	0000h

		LD	SP,	0080h	; ADDED FOR TESTING PURPOSES.
		PUSH	HL		; ADDED FOR TESTING PURPOSES.
		LD 	HL,	3810h	; ADDED FOR TESTING PURPOSES.
		LD	(HL), 00h	; ADDED FOR TESTING PURPOSES.
		LD	HL,	3820h	; ADDED FOR TESTING PURPOSES.
		LD  (HL), 01h	; ADDED FOR TESTING PURPOSES.
		POP	HL			; ADDED FOR TESTING PURPOSES.
		CALL	INPUT	; ADDED FOR TESTING PURPOSES.		
		HALT			; ADDED FOR TESTING PURPOSES.
		
INPUT:	PUSH	BC		; SAVE REGISTERS.
		PUSH	HL
		
; INP002, INP005, INP010 = READ 0-7 LOGIC (SEE PAGE 136).
INP002:	LD	A,	(3810h)	; KEYBOARD ROW 4.
		OR	A			; TEST FOR NON-ZERO.
		JP 	Z, 	INP010	; GO IF NON.
		LD	C,	0FFh	; COLUMN COUNT.
INP005:	INC	C			; BUMP COUNT.
		RRCA			; SHIFT OUT.
		JP	NC,	INP005	; GO IF NOT CARRY.
		LD	A,	C		; COUNT TO A.
		JP	INP020		; CONTINUE.
INP010:	LD	A,	(3820h)	; KEYBOARD ROW 5.
		AND	1			; GET "8" KEY ONLY.
		JP	Z, INP002	; GO IF NONE.
		LD	A,	8		; FOR '8' KEY.
		
; READ 8 LOGIC.
INP020:	
;		LD	HL,	100		; 100 mS DELAY.
;		CALL DELAY		; DELAY
		POP	HL			; RESTORE REGISTERS.
		POP BC		
		RET

.END