From: Jon Langseth <jon.langseth@ntnu.no>
Date: Mon, 23 Jan 2017 18:15:27 +0000 (+0100)
Subject: Sounds!
X-Git-Url: https://git.defcon.no/?a=commitdiff_plain;h=2112f4e99ca8166a75b7e1594af89d4b69265d97;p=z80cpm

Sounds!
---

diff --git a/soundtest1.asm b/soundtest1.asm
new file mode 100644
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