diff --git a/Source/Apps/tone3.asm b/Source/Apps/tone3.asm new file mode 100644 index 00000000..620841e0 --- /dev/null +++ b/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 +