Sounds!

diff --git a/soundtest1.asm b/soundtest1.asm
new file mode 100644 (file)
index 0000000..85875b9
--- /dev/null
+++ b/soundtest1.asm
@@ -0,0 +1,73 @@
+; soundtest1.asm
+; Requires an AY-3-891x or YM2149, with address decoding making
+; a write/read to $50 a data write/read, a write to $51 an address write,
+; and any other combination being an AY Idle condition.
+; Supernaive bruteforce approach, with random delay values.
+; Produces a frequency sweep by counting down 0..255
+
+CPU Z80
+OUTPUT HEX
+
+* = $100
+START          LD A, 7
+               OUT     ($51), A
+               LD A, $FF
+               OUT     ($50), A
+
+               LD A, 8
+               OUT     ($51), A
+               LD A, 9
+               OUT     ($50), A
+
+               LD A, 9
+               OUT     ($51), A
+               LD A, 0
+               OUT     ($50), A
+
+               LD A, $A
+               OUT     ($51), A
+               LD A, 0
+               OUT     ($50), A
+
+               LD A, 7
+               OUT     ($51), A
+               LD A, $FE
+               OUT     ($50), A
+
+               LD A, 1
+               OUT     ($51), A
+               LD A, 1
+               OUT     ($50), A
+
+               LD A, 0
+               OUT     ($51), A
+
+               LD A, $FF
+LOOP1          OUT     ($50), A
+               PUSH AF
+               LD A, 8
+               CALL DELAY
+               POP AF
+               DEC A
+               JR NZ, LOOP1
+
+               LD A, 7
+               OUT     ($51), A
+               LD A, $FF
+               OUT     ($50), A
+
+               RET
+
+; End of main code.
+
+;Start of delay routine..
+DELAY          PUSH BC
+DLY_START      LD C, 10
+DLY_LOOPO      LD B, 0
+DLY_LOOPI      DJNZ DLY_LOOPI
+               DEC C
+               JR NZ, DLY_LOOPO
+               DEC A
+               JR NZ, DLY_START
+               POP BC
+               RET