Create tone3.asm

Source/Apps/tone3.asm

@@ -0,0 +1,35 @@
+; program to test user buzzer/speaker on Z80 MBC clock board
+; by Andrew Lynch, 6 Jul 2021
+
+	org $0100
+
+	LD	HL,$7FFF	; INITIALIZE OUTER LOOP
+	LD	DE,$0001	; DECREMENT VALUE
+
+START:
+
+	LD	A,%00000100
+	OUT	($70),A		; TURN ON SPEAKER
+
+	LD	B,$80		; HOLD SPEAKER ON FOR 128 COUNTS
+LOOP1:	DJNZ	LOOP1
+
+	LD	A,%00000000
+	OUT	($70),A		; TURN OFF SPEAKER
+
+	LD	B,$80		; HOLD SPEAKER OFF FOR 128 COUNTS
+LOOP2:	DJNZ	LOOP2
+
+	SBC	HL,DE		; REDUCE OUTER LOOP BY 1
+
+	JR	NZ,START	; LOOP 32768 TIMES, ABOUT 15 SECONDS
+
+	LD	A,%00000011
+	OUT	($70),A		; TURN ON BOTH USER LEDS
+
+;	HALT			; HALT & TURN ON HALT LED
+
+    RET
+
+	end
+