From 8c2c0f45b598ee1778eabffb54d9b599d20833cf Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sat, 9 May 2020 22:57:26 +1000
Subject: [PATCH 1/7] sn76489: refactor to support full note range

No need to full mapping table
Range can be consistent with all sound drivers
---
 Source/HBIOS/audio.inc   |   6 +-
 Source/HBIOS/sn76489.asm | 400 ++++++++++++---------------------------
 2 files changed, 124 insertions(+), 282 deletions(-)

diff --git a/Source/HBIOS/audio.inc b/Source/HBIOS/audio.inc
index 2b69513b..09469326 100644
--- a/Source/HBIOS/audio.inc
+++ b/Source/HBIOS/audio.inc
@@ -6,10 +6,11 @@
 #DEFINE AUDTRACE_E	PUSH AF \ LD A, E \ CALL PRTHEXBYTE \ POP AF
 #DEFINE AUDTRACE_L	PUSH AF \ LD A, L \ CALL PRTHEXBYTE \ POP AF
 #DEFINE AUDTRACE_HL	CALL PRTHEXWORDHL
-#DEFINE AUDTRACE_DE	PUSH DE \ PUSH DE \ POP HL \ CALL PRTHEXWORDHL \ POP DE
+#DEFINE AUDTRACE_BC	PUSH HL \ PUSH BC \ POP HL \ CALL PRTHEXWORDHL \ POP HL
+#DEFINE AUDTRACE_DE	PUSH HL \ PUSH DE \ POP HL \ CALL PRTHEXWORDHL \ POP HL
 #DEFINE AUDTRACE_IY	PUSH HL \ PUSH IY \ POP HL \ CALL PRTHEXWORDHL \ POP HL
 
-#DEFINE AUDDEBUG(S) CALL PRTSTRD \ .TEXT S \ .TEXT "$"	; $$$$$$ PRINT STRING S TO CONSOLE - PRTD("HELLO") - NO TRAILING $ REQUIRED
+#DEFINE AUDDEBUG(S) push hl \ CALL PRTSTRD \ .TEXT S \ .TEXT "$" \ pop hl	; $$$$$$ PRINT STRING S TO CONSOLE - PRTD("HELLO") - NO TRAILING $ REQUIRED
 
 #DEFINE AUDTRACE_CR AUDDEBUG("\r\n$")
 
@@ -20,6 +21,7 @@
 #DEFINE AUDTRACE_D
 #DEFINE AUDTRACE_E
 #DEFINE AUDTRACE_L
+#DEFINE AUDTRACE_BC
 #DEFINE AUDTRACE_HL
 #DEFINE AUDTRACE_DE
 #DEFINE AUDTRACE_IY
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index f8181983..8f90e360 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -26,19 +26,6 @@ SN7CLKDIVIDER	.EQU	4
 SN7CLK		.EQU	CPUOSC / SN7CLKDIVIDER
 SN7RATIO	.EQU	SN7CLK * 100 / 32
 
-
-SN7_FIRST_NOTE	.EQU	5827		; A1#
-SN7_LAST_NOTE	.EQU	209300		; C7
-
-A1S		.EQU	SN7RATIO / SN7_FIRST_NOTE
-C7		.EQU	SN7RATIO / SN7_LAST_NOTE
-
-       .ECHO "SN76489: range of A1# (period: "
-       .ECHO A1S
-       .ECHO ") to C7 (period: "
-       .ECHO C7
-       .ECHO ")\n"
-
 #INCLUDE "audio.inc"
 
 SN76489_INIT:
@@ -112,22 +99,19 @@ SN7_VOLUME:
 	XOR	A			; SIGNAL SUCCESS
 	RET
 
-
-
 SN7_NOTE:
 	AUDTRACE(SNT_NOTE)
 	AUDTRACE_HL
 	AUDTRACE_CR
 
-	LD	H,0
-	ADD	HL, HL			; SHIFT RIGHT (MULT 2) -INDEX INTO SN7NOTETBL TABLE OF WORDS
-					; TEST IF HL IS LARGER THAN SN7NOTETBL SIZE
-	OR	A			; CLEAR CARRY FLAG
-	LD	DE, SIZ_SN7NOTETBL
-	SBC	HL, DE
-	JR	NC, SN7_NOTE1		; INCOMING HL DOES NOT MAP INTO SN7NOTETBL
+	LD	B, H
+	LD	C, L
+	LD	DE, 48
 
-	ADD	HL, DE			; RESTORE HL
+	CALL	_DIV16
+					; BC IS OCTAVE COUNT
+					; HL is NOTE WITIN ACTAVE
+	ADD	HL, HL
 	LD	DE, SN7NOTETBL
 	ADD	HL, DE
 
@@ -136,10 +120,57 @@ SN7_NOTE:
 	LD	H, (HL)
 	LD	L, A
 
-	JR	SN7_PERIOD		; APPLY PERIOD
-
+	INC	C
 SN7_NOTE1:
-	OR	$FF			; NOT IMPLEMENTED YET
+	DEC	C
+	JR	Z, SN7_NOTE2
+	SRL	H
+  	RR	L
+	JR	SN7_NOTE1
+
+SN7_NOTE2:
+	LD	A, L
+	OR	H
+	JR	NZ, SN7_PERIOD
+
+	LD	H, $FF
+	LD	L, $FF
+	JR	SN7_PERIOD
+
+; Divide 16-bit values (with 16-bit result)
+; In: Divide BC by divider DE
+; Out: BC = result, HL = rest
+;
+_DIV16:
+	LD	HL, 0
+	LD	A, B
+	LD	B, 8
+DIV16_LOOP1:
+	RLA
+	ADC	HL, HL
+	SBC	HL, DE
+	JR	NC, DIV16_NOADD1
+	ADD	HL, DE
+DIV16_NOADD1:
+	DJNZ	DIV16_LOOP1
+	RLA
+	CPL
+	LD	B, A
+	LD	A, C
+	LD	C, B
+	LD	B, 8
+DIV16_LOOP2:
+	RLA
+	ADC	HL, HL
+	SBC	HL, DE
+	JR	NC, DIV16_NOADD2
+	ADD	HL, DE
+DIV16_NOADD2:
+	DJNZ	DIV16_LOOP2
+	RLA
+	CPL
+	LD	B, C
+	LD	C, A
 	RET
 
 SN7_PERIOD:
@@ -147,11 +178,17 @@ SN7_PERIOD:
 	AUDTRACE_HL
 	AUDTRACE_CR
 
-	LD	A, H
-	CP	$04
-	JP	NC, SN7_QUERY_PERIOD1	; RETURN NZ IF NUMBER TOO LARGE
+	; LD	A, H			; IF ZERO - ERROR
+	; OR	L
+	; JR	Z, SN7_QUERY_PERIOD1
+
+	LD	(SN7_PENDING_PERIOD), HL ;ASSUME SUCCESS
+
+	OR	A			; IF >= 401 ERROR
+	LD	DE, $401
+	SBC	HL, DE
+	JR	NC, SN7_QUERY_PERIOD1
 
-	LD	(SN7_PENDING_PERIOD), HL
 	XOR	A			; SIGNAL SUCCESS
 	RET
 
@@ -361,257 +398,60 @@ SNT_PLAY		.DB	"\r\nSN7_PLAY CH: $"
 SNT_REGWR		.DB	"\r\nOUT SN76489, $"
 #ENDIF
 
-; THE FREQUENCY BY QUARTER TONE STARTING AT A1#
+; THE FREQUENCY BY QUARTER TONE STARTING AT A0#
+; OCATVE 0 - not suported by this driver
+; FIRST PLAYABLE NOTE WILL BE $2E - 2 quater tones below a1#
+; A1# is $30
+
 SN7NOTETBL:
-	.DW	A1S	 ; 5827
-	.DW	SN7RATIO / 5912
-	.DW	SN7RATIO / 5998
-	.DW	SN7RATIO / 6085
-	.DW	SN7RATIO / 6174
-	.DW	SN7RATIO / 6264
-	.DW	SN7RATIO / 6355
-	.DW	SN7RATIO / 6447
-	.DW	SN7RATIO / 6541
-	.DW	SN7RATIO / 6636
-	.DW	SN7RATIO / 6733
-	.DW	SN7RATIO / 6831
-	.DW	SN7RATIO / 6930
-	.DW	SN7RATIO / 7031
-	.DW	SN7RATIO / 7133
-	.DW	SN7RATIO / 7237
-	.DW	SN7RATIO / 7342
-	.DW	SN7RATIO / 7449
-	.DW	SN7RATIO / 7557
-	.DW	SN7RATIO / 7667
-	.DW	SN7RATIO / 7778
-	.DW	SN7RATIO / 7891
-	.DW	SN7RATIO / 8006
-	.DW	SN7RATIO / 8122
-	.DW	SN7RATIO / 8241
-	.DW	SN7RATIO / 8361
-	.DW	SN7RATIO / 8482
-	.DW	SN7RATIO / 8606
-	.DW	SN7RATIO / 8731
-	.DW	SN7RATIO / 8858
-	.DW	SN7RATIO / 8987
-	.DW	SN7RATIO / 9118
-	.DW	SN7RATIO / 9250
-	.DW	SN7RATIO / 9385
-	.DW	SN7RATIO / 9521
-	.DW	SN7RATIO / 9660
-	.DW	SN7RATIO / 9800
-	.DW	SN7RATIO / 9943
-	.DW	SN7RATIO / 10087
-	.DW	SN7RATIO / 10234
-	.DW	SN7RATIO / 10383
-	.DW	SN7RATIO / 10534
-	.DW	SN7RATIO / 10687
-	.DW	SN7RATIO / 10843
-	.DW	SN7RATIO / 11000
-	.DW	SN7RATIO / 11160
-	.DW	SN7RATIO / 11322
-	.DW	SN7RATIO / 11487
-	.DW	SN7RATIO / 11654
-	.DW	SN7RATIO / 11824
-	.DW	SN7RATIO / 11995
-	.DW	SN7RATIO / 12170
-	.DW	SN7RATIO / 12347
-	.DW	SN7RATIO / 12527
-	.DW	SN7RATIO / 12709
-	.DW	SN7RATIO / 12894
-	.DW	SN7RATIO / 13081
-	.DW	SN7RATIO / 13271
-	.DW	SN7RATIO / 13464
-	.DW	SN7RATIO / 13660
-	.DW	SN7RATIO / 13859
-	.DW	SN7RATIO / 14061
-	.DW	SN7RATIO / 14265
-	.DW	SN7RATIO / 14473
-	.DW	SN7RATIO / 14683
-	.DW	SN7RATIO / 14897
-	.DW	SN7RATIO / 15113
-	.DW	SN7RATIO / 15333
-	.DW	SN7RATIO / 15556
-	.DW	SN7RATIO / 15782
-	.DW	SN7RATIO / 16012
-	.DW	SN7RATIO / 16245
-	.DW	SN7RATIO / 16481
-	.DW	SN7RATIO / 16721
-	.DW	SN7RATIO / 16964
-	.DW	SN7RATIO / 17211
-	.DW	SN7RATIO / 17461
-	.DW	SN7RATIO / 17715
-	.DW	SN7RATIO / 17973
-	.DW	SN7RATIO / 18234
-	.DW	SN7RATIO / 18500
-	.DW	SN7RATIO / 18769
-	.DW	SN7RATIO / 19042
-	.DW	SN7RATIO / 19319
-	.DW	SN7RATIO / 19600
-	.DW	SN7RATIO / 19885
-	.DW	SN7RATIO / 20174
-	.DW	SN7RATIO / 20468
-	.DW	SN7RATIO / 20765
-	.DW	SN7RATIO / 21067
-	.DW	SN7RATIO / 21373
-	.DW	SN7RATIO / 21684
-	.DW	SN7RATIO / 22000
-	.DW	SN7RATIO / 22320
-	.DW	SN7RATIO / 22645
-	.DW	SN7RATIO / 22974
-	.DW	SN7RATIO / 23308
-	.DW	SN7RATIO / 23647
-	.DW	SN7RATIO / 23991
-	.DW	SN7RATIO / 24340
-	.DW	SN7RATIO / 24694
-	.DW	SN7RATIO / 25053
-	.DW	SN7RATIO / 25418
-	.DW	SN7RATIO / 25787
-	.DW	SN7RATIO / 26163
-	.DW	SN7RATIO / 26544
-	.DW	SN7RATIO / 26930
-	.DW	SN7RATIO / 27321
-	.DW	SN7RATIO / 27718
-	.DW	SN7RATIO / 28121
-	.DW	SN7RATIO / 28530
-	.DW	SN7RATIO / 28945
-	.DW	SN7RATIO / 29366
-	.DW	SN7RATIO / 29793
-	.DW	SN7RATIO / 30226
-	.DW	SN7RATIO / 30666
-	.DW	SN7RATIO / 31113
-	.DW	SN7RATIO / 31566
-	.DW	SN7RATIO / 32025
-	.DW	SN7RATIO / 32490
-	.DW	SN7RATIO / 32963
-	.DW	SN7RATIO / 33442
-	.DW	SN7RATIO / 33929
-	.DW	SN7RATIO / 34422
-	.DW	SN7RATIO / 34923
-	.DW	SN7RATIO / 35431
-	.DW	SN7RATIO / 35946
-	.DW	SN7RATIO / 36469
-	.DW	SN7RATIO / 36999
-	.DW	SN7RATIO / 37537
-	.DW	SN7RATIO / 38083
-	.DW	SN7RATIO / 38637
-	.DW	SN7RATIO / 39200
-	.DW	SN7RATIO / 39770
-	.DW	SN7RATIO / 40349
-	.DW	SN7RATIO / 40936
-	.DW	SN7RATIO / 41530
-	.DW	SN7RATIO / 42134
-	.DW	SN7RATIO / 42747
-	.DW	SN7RATIO / 43369
-	.DW	SN7RATIO / 44000
-	.DW	SN7RATIO / 44640
-	.DW	SN7RATIO / 45289
-	.DW	SN7RATIO / 45948
-	.DW	SN7RATIO / 46616
-	.DW	SN7RATIO / 47294
-	.DW	SN7RATIO / 47982
-	.DW	SN7RATIO / 48680
-	.DW	SN7RATIO / 49388
-	.DW	SN7RATIO / 50106
-	.DW	SN7RATIO / 50835
-	.DW	SN7RATIO / 51575
-	.DW	SN7RATIO / 52325
-	.DW	SN7RATIO / 53086
-	.DW	SN7RATIO / 53858
-	.DW	SN7RATIO / 54642
-	.DW	SN7RATIO / 55437
-	.DW	SN7RATIO / 56243
-	.DW	SN7RATIO / 57061
-	.DW	SN7RATIO / 57891
-	.DW	SN7RATIO / 58733
-	.DW	SN7RATIO / 59587
-	.DW	SN7RATIO / 60454
-	.DW	SN7RATIO / 61333
-	.DW	SN7RATIO / 62225
-	.DW	SN7RATIO / 63130
-	.DW	SN7RATIO / 64048
-	.DW	SN7RATIO / 64980
-	.DW	SN7RATIO / 65925
-	.DW	SN7RATIO / 66884
-	.DW	SN7RATIO / 67857
-	.DW	SN7RATIO / 68844
-	.DW	SN7RATIO / 69846
-	.DW	SN7RATIO / 70862
-	.DW	SN7RATIO / 71893
-	.DW	SN7RATIO / 72938
-	.DW	SN7RATIO / 73999
-	.DW	SN7RATIO / 75075
-	.DW	SN7RATIO / 76167
-	.DW	SN7RATIO / 77275
-	.DW	SN7RATIO / 78399
-	.DW	SN7RATIO / 79539
-	.DW	SN7RATIO / 80696
-	.DW	SN7RATIO / 81870
-	.DW	SN7RATIO / 83061
-	.DW	SN7RATIO / 84269
-	.DW	SN7RATIO / 85495
-	.DW	SN7RATIO / 86738
-	.DW	SN7RATIO / 88000
-	.DW	SN7RATIO / 89280
-	.DW	SN7RATIO / 90579
-	.DW	SN7RATIO / 91896
-	.DW	SN7RATIO / 93233
-	.DW	SN7RATIO / 94589
-	.DW	SN7RATIO / 95965
-	.DW	SN7RATIO / 97361
-	.DW	SN7RATIO / 98777
-	.DW	SN7RATIO / 100214
-	.DW	SN7RATIO / 101671
-	.DW	SN7RATIO / 103150
-	.DW	SN7RATIO / 104650
-	.DW	SN7RATIO / 106172
-	.DW	SN7RATIO / 107716
-	.DW	SN7RATIO / 109283
-	.DW	SN7RATIO / 110873
-	.DW	SN7RATIO / 112486
-	.DW	SN7RATIO / 114122
-	.DW	SN7RATIO / 115782
-	.DW	SN7RATIO / 117466
-	.DW	SN7RATIO / 119175
-	.DW	SN7RATIO / 120908
-	.DW	SN7RATIO / 122667
-	.DW	SN7RATIO / 124451
-	.DW	SN7RATIO / 126261
-	.DW	SN7RATIO / 128098
-	.DW	SN7RATIO / 129961
-	.DW	SN7RATIO / 131851
-	.DW	SN7RATIO / 133769
-	.DW	SN7RATIO / 135715
-	.DW	SN7RATIO / 137689
-	.DW	SN7RATIO / 139691
-	.DW	SN7RATIO / 141723
-	.DW	SN7RATIO / 143784
-	.DW	SN7RATIO / 145876
-	.DW	SN7RATIO / 147998
-	.DW	SN7RATIO / 150151
-	.DW	SN7RATIO / 152335
-	.DW	SN7RATIO / 154550
-	.DW	SN7RATIO / 156798
-	.DW	SN7RATIO / 159079
-	.DW	SN7RATIO / 161393
-	.DW	SN7RATIO / 163740
-	.DW	SN7RATIO / 166122
-	.DW	SN7RATIO / 168538
-	.DW	SN7RATIO / 170990
-	.DW	SN7RATIO / 173477
-	.DW	SN7RATIO / 176000
-	.DW	SN7RATIO / 178560
-	.DW	SN7RATIO / 181157
-	.DW	SN7RATIO / 183792
-	.DW	SN7RATIO / 186466
-	.DW	SN7RATIO / 189178
-	.DW	SN7RATIO / 191930
-	.DW	SN7RATIO / 194722
-	.DW	SN7RATIO / 197553
-	.DW	SN7RATIO / 200426
-	.DW	SN7RATIO / 203342
-	.DW	SN7RATIO / 206299
-	.DW	C7	 ; 209300
+	.DW	SN7RATIO / 2913
+	.DW	SN7RATIO / 2956
+	.DW	SN7RATIO / 2999
+	.DW	SN7RATIO / 3042
+	.DW	SN7RATIO / 3086
+	.DW	SN7RATIO / 3131
+	.DW	SN7RATIO / 3177
+	.DW	SN7RATIO / 3223
+	.DW	SN7RATIO / 3270
+	.DW	SN7RATIO / 3318
+	.DW	SN7RATIO / 3366
+	.DW	SN7RATIO / 3415
+	.DW	SN7RATIO / 3464
+	.DW	SN7RATIO / 3515
+	.DW	SN7RATIO / 3566
+	.DW	SN7RATIO / 3618
+	.DW	SN7RATIO / 3670
+	.DW	SN7RATIO / 3724
+	.DW	SN7RATIO / 3778
+	.DW	SN7RATIO / 3833
+	.DW	SN7RATIO / 3889
+	.DW	SN7RATIO / 3945
+	.DW	SN7RATIO / 4003
+	.DW	SN7RATIO / 4061
+	.DW	SN7RATIO / 4120
+	.DW	SN7RATIO / 4180
+	.DW	SN7RATIO / 4241
+	.DW	SN7RATIO / 4302
+	.DW	SN7RATIO / 4365
+	.DW	SN7RATIO / 4428
+	.DW	SN7RATIO / 4493
+	.DW	SN7RATIO / 4558
+	.DW	SN7RATIO / 4624
+	.DW	SN7RATIO / 4692
+	.DW	SN7RATIO / 4760
+	.DW	SN7RATIO / 4829
+	.DW	SN7RATIO / 4899
+	.DW	SN7RATIO / 4971
+	.DW	SN7RATIO / 5043
+	.DW	SN7RATIO / 5116
+	.DW	SN7RATIO / 5191
+	.DW	SN7RATIO / 5266
+	.DW	SN7RATIO / 5343
+	.DW	SN7RATIO / 5421
+	.DW	SN7RATIO / 5499
+	.DW	SN7RATIO / 5579
+	.DW	SN7RATIO / 5661
+	.DW	SN7RATIO / 5743
 
 SIZ_SN7NOTETBL	.EQU	$ - SN7NOTETBL
 		.ECHO	"SN76489 approx "

From 98a63cefa9845f455559af4968cf9eda893d7d55 Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sun, 10 May 2020 12:05:45 +1000
Subject: [PATCH 2/7] SN76489: refactor - remove custom div16 function - use
 common hbios util div16 function

---
 Source/HBIOS/sn76489.asm | 67 +++++++++-------------------------------
 1 file changed, 14 insertions(+), 53 deletions(-)

diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index 8f90e360..182cc6a5 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -5,6 +5,9 @@
 ;======================================================================
 ;
 ; TODO:
+; 1. PROVIDE SUPPORT FOR NOISE CHANNEL
+; 2. FOR PERIOD SET, MAP 400 TO 0 AND RETURN ERROR FOR 000
+; 3. DOES THIS WORK FOR FASTER CPUS? ONLY BEEN TEST ON A Z80 7MHZ UNIT
 ;
 ;======================================================================
 ; CONSTANTS
@@ -104,13 +107,10 @@ SN7_NOTE:
 	AUDTRACE_HL
 	AUDTRACE_CR
 
-	LD	B, H
-	LD	C, L
 	LD	DE, 48
-
-	CALL	_DIV16
+	CALL	DIV16
 					; BC IS OCTAVE COUNT
-					; HL is NOTE WITIN ACTAVE
+					; HL is NOTE WITIN OCTAVE
 	ADD	HL, HL
 	LD	DE, SN7NOTETBL
 	ADD	HL, DE
@@ -129,55 +129,21 @@ SN7_NOTE1:
 	JR	SN7_NOTE1
 
 SN7_NOTE2:
-	LD	A, L
+	LD	A, L			; IF WE GENERATE ZERO - RETURN ERROR
 	OR	H
-	JR	NZ, SN7_PERIOD
+	JR	NZ, SN7_PERIOD		; OTHERWISE APPLY THE CALCULATED PERIOD
 
 	LD	H, $FF
 	LD	L, $FF
 	JR	SN7_PERIOD
 
-; Divide 16-bit values (with 16-bit result)
-; In: Divide BC by divider DE
-; Out: BC = result, HL = rest
-;
-_DIV16:
-	LD	HL, 0
-	LD	A, B
-	LD	B, 8
-DIV16_LOOP1:
-	RLA
-	ADC	HL, HL
-	SBC	HL, DE
-	JR	NC, DIV16_NOADD1
-	ADD	HL, DE
-DIV16_NOADD1:
-	DJNZ	DIV16_LOOP1
-	RLA
-	CPL
-	LD	B, A
-	LD	A, C
-	LD	C, B
-	LD	B, 8
-DIV16_LOOP2:
-	RLA
-	ADC	HL, HL
-	SBC	HL, DE
-	JR	NC, DIV16_NOADD2
-	ADD	HL, DE
-DIV16_NOADD2:
-	DJNZ	DIV16_LOOP2
-	RLA
-	CPL
-	LD	B, C
-	LD	C, A
-	RET
-
 SN7_PERIOD:
 	AUDTRACE(SNT_PERIOD)
 	AUDTRACE_HL
 	AUDTRACE_CR
 
+	; TODO: MAKE ZERO BE AN INVALID VALUE (USE 400) TO INDICATE LOWEST NOTE
+	; NEED TO UPDATE TUNE.ASM TO SUPPORT THIS?
 	; LD	A, H			; IF ZERO - ERROR
 	; OR	L
 	; JR	Z, SN7_QUERY_PERIOD1
@@ -398,10 +364,11 @@ SNT_PLAY		.DB	"\r\nSN7_PLAY CH: $"
 SNT_REGWR		.DB	"\r\nOUT SN76489, $"
 #ENDIF
 
-; THE FREQUENCY BY QUARTER TONE STARTING AT A0#
-; OCATVE 0 - not suported by this driver
-; FIRST PLAYABLE NOTE WILL BE $2E - 2 quater tones below a1#
-; A1# is $30
+; THE FREQUENCY BY QUARTER TONE STARTING AT A0# OCATVE 0
+; USED TO MAP EACH OCTAVE (DIV BY 2 TO JUMP AN OCTAVE UP)
+; FIRST PLAYABLE NOTE WILL BE $2E
+; ASSUMING A CLOCK OF 1843200 THIS MAPS TO
+; 2 QUATER TONES BELOW A1#, WITH A1# AT $30
 
 SN7NOTETBL:
 	.DW	SN7RATIO / 2913
@@ -454,9 +421,3 @@ SN7NOTETBL:
 	.DW	SN7RATIO / 5743
 
 SIZ_SN7NOTETBL	.EQU	$ - SN7NOTETBL
-		.ECHO	"SN76489 approx "
-		.ECHO	SIZ_SN7NOTETBL / 2 / 4 /12
-		.ECHO	" Octaves.  Last note index supported: "
-
-		.ECHO SIZ_SN7NOTETBL / 2
-		.ECHO "\n"

From 7330928dcacebc6d0b984789a24606258b2db118 Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sun, 10 May 2020 12:25:33 +1000
Subject: [PATCH 3/7] SN76489: Moved clock configuration from driver to
 platform config files

---
 Source/HBIOS/cfg_dyno.asm   | 2 ++
 Source/HBIOS/cfg_ezz80.asm  | 2 ++
 Source/HBIOS/cfg_master.asm | 2 ++
 Source/HBIOS/cfg_mk4.asm    | 2 ++
 Source/HBIOS/cfg_n8.asm     | 2 ++
 Source/HBIOS/cfg_rcz180.asm | 2 ++
 Source/HBIOS/cfg_rcz80.asm  | 2 ++
 Source/HBIOS/cfg_sbc.asm    | 2 ++
 Source/HBIOS/cfg_scz180.asm | 2 ++
 Source/HBIOS/cfg_zeta.asm   | 2 ++
 Source/HBIOS/cfg_zeta2.asm  | 2 ++
 Source/HBIOS/sn76489.asm    | 6 ++++--
 12 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/Source/HBIOS/cfg_dyno.asm b/Source/HBIOS/cfg_dyno.asm
index 058816cd..c0c936a3 100644
--- a/Source/HBIOS/cfg_dyno.asm
+++ b/Source/HBIOS/cfg_dyno.asm
@@ -155,6 +155,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_RCZ180	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_ezz80.asm b/Source/HBIOS/cfg_ezz80.asm
index 9319a4b5..2ea3df23 100644
--- a/Source/HBIOS/cfg_ezz80.asm
+++ b/Source/HBIOS/cfg_ezz80.asm
@@ -180,6 +180,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_RCZ80	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_master.asm b/Source/HBIOS/cfg_master.asm
index 31ff520a..f46779c8 100644
--- a/Source/HBIOS/cfg_master.asm
+++ b/Source/HBIOS/cfg_master.asm
@@ -235,6 +235,8 @@ UFBASE		.EQU	$0C		; UF: REGISTERS BASE ADR
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_NONE	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index 6817d124..fc316e15 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -189,6 +189,8 @@ UFBASE		.EQU	$0C		; UF: REGISTERS BASE ADR
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_SCG	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index bbcc60fc..88069943 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -189,6 +189,8 @@ FIFO_BASE	.EQU	$0C		; UF: REGISTERS BASE ADR
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	TRUE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_N8	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_rcz180.asm b/Source/HBIOS/cfg_rcz180.asm
index 8fc7d329..ebc473e2 100644
--- a/Source/HBIOS/cfg_rcz180.asm
+++ b/Source/HBIOS/cfg_rcz180.asm
@@ -189,6 +189,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_RCZ180	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_rcz80.asm b/Source/HBIOS/cfg_rcz80.asm
index 3d279a45..dfd4d72a 100644
--- a/Source/HBIOS/cfg_rcz80.asm
+++ b/Source/HBIOS/cfg_rcz80.asm
@@ -195,6 +195,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_RCZ80	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_sbc.asm b/Source/HBIOS/cfg_sbc.asm
index 7803b1a0..c37f0ef4 100644
--- a/Source/HBIOS/cfg_sbc.asm
+++ b/Source/HBIOS/cfg_sbc.asm
@@ -191,6 +191,8 @@ UFBASE		.EQU	$0C		; UF: REGISTERS BASE ADR
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_SCG	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_scz180.asm b/Source/HBIOS/cfg_scz180.asm
index 483f043f..68fbccf6 100644
--- a/Source/HBIOS/cfg_scz180.asm
+++ b/Source/HBIOS/cfg_scz180.asm
@@ -184,6 +184,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_RCZ180	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_zeta.asm b/Source/HBIOS/cfg_zeta.asm
index 8898ceea..2d9cce1e 100644
--- a/Source/HBIOS/cfg_zeta.asm
+++ b/Source/HBIOS/cfg_zeta.asm
@@ -136,6 +136,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_NONE	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_zeta2.asm b/Source/HBIOS/cfg_zeta2.asm
index 28ab8d69..fbbaf6ac 100644
--- a/Source/HBIOS/cfg_zeta2.asm
+++ b/Source/HBIOS/cfg_zeta2.asm
@@ -146,6 +146,8 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 ;
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
+
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
 AYMODE		.EQU	AYMODE_NONE	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index 182cc6a5..cb062d53 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -25,10 +25,12 @@ CHANNEL_1_SILENT	.EQU	$BF
 CHANNEL_2_SILENT	.EQU	$DF
 CHANNEL_3_SILENT	.EQU	$FF
 
-SN7CLKDIVIDER	.EQU	4
-SN7CLK		.EQU	CPUOSC / SN7CLKDIVIDER
 SN7RATIO	.EQU	SN7CLK * 100 / 32
 
+	.ECHO	"SN76489 CLOCK: "
+	.ECHO	SN7CLK
+	.ECHO	"\n"
+
 #INCLUDE "audio.inc"
 
 SN76489_INIT:

From 625e696f68895a866bb9294a898b45863474ba5a Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sun, 10 May 2020 13:15:21 +1000
Subject: [PATCH 4/7] whitespace

---
 Source/HBIOS/ay38910.asm | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Source/HBIOS/ay38910.asm b/Source/HBIOS/ay38910.asm
index b703bad5..fcb591a1 100644
--- a/Source/HBIOS/ay38910.asm
+++ b/Source/HBIOS/ay38910.asm
@@ -20,7 +20,7 @@ AY_RIN		.EQU	AY_RSEL
 AY_ACR		.EQU	N8_DEFACR
 #ENDIF
 ;
-#IF (AYMODE == AYMODE_RCZ80)	
+#IF (AYMODE == AYMODE_RCZ80)
 AY_RSEL		.EQU	$D8
 AY_RDAT		.EQU	$D0
 AY_RIN		.EQU	AY_RSEL+AY_RCSND
@@ -71,7 +71,7 @@ AY_NOISECNT	.EQU	1		; COUNT NUMBER OF NOISE CHANNELS
 ;
 AY_PHICLK	.EQU	3579545		; MSX NTSC COLOUR BURST FREQ = 315/88
 ;AY_PHICLK	.EQU	3500000		; ZX SPECTRUM 3.5MHZ
-;AY_PHICLK	.EQU	4000000		; RETROBREW SCB-SCG 
+;AY_PHICLK	.EQU	4000000		; RETROBREW SCB-SCG
 AY_CLKDIV	.EQU	2
 AY_CLK		.EQU	AY_PHICLK / AY_CLKDIV
 AY_RATIO	.EQU	AY_CLK * 100 / 16
@@ -99,7 +99,7 @@ AY38910_INIT:
 #ENDIF
 ;
 	LD	DE,(AY_R2CHBP*256)+$55	; SIMPLE HARDWARE PROBE
-	CALL	AY_WRTPSG		; WRITE AND 
+	CALL	AY_WRTPSG		; WRITE AND
 	CALL	AY_RDPSG		; READ TO A
 	LD	A,$55			; SOUND CHANNEL
 	CP	E			; REGISTER
@@ -107,7 +107,7 @@ AY38910_INIT:
 ;
 	CALL	PRTSTRD \ .TEXT " NOT PRESENT$"
 ;
-	LD	A,$FF			; UNSUCCESSFULL INIT		
+	LD	A,$FF			; UNSUCCESSFULL INIT
 	RET
 ;
 AY_FND:	LD	IY, AY_IDAT		; SETUP FUNCTION TABLE
@@ -275,7 +275,7 @@ AY_PLAY:
 	INC	A
 	JR	Z, AY_PLAY1		; PERIOD IS TOO LARGE, UNABLE TO PLAY
 ;
-	PUSH	HL			
+	PUSH	HL
 	PUSH	DE
 	LD	A,D			; LIMIT CHANNEL 0-2
 	AND	$3			; AND INDEX TO THE
@@ -460,7 +460,7 @@ AYT_REGWR		.DB	"\r\nOUT AY-3-8910 $"
 #ENDIF
 ;
 ;======================================================================
-;	BBC MICRO QUARTER TONE FREQUENCY TABLE 
+;	BBC MICRO QUARTER TONE FREQUENCY TABLE
 ;======================================================================
 ;
 AY3NOTETBL:

From 5e65fcba1347515f13748416e26f5ef408a5c0d6 Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sun, 10 May 2020 13:17:20 +1000
Subject: [PATCH 5/7] AY38910: Refactored to use a common function for note
 mapping as SN76489 driver

---
 Source/HBIOS/audio.inc      |  43 +++++
 Source/HBIOS/ay38910.asm    | 373 +++++++-----------------------------
 Source/HBIOS/cfg_dyno.asm   |   3 +-
 Source/HBIOS/cfg_ezz80.asm  |   1 +
 Source/HBIOS/cfg_master.asm |   1 +
 Source/HBIOS/cfg_mk4.asm    |   1 +
 Source/HBIOS/cfg_n8.asm     |   1 +
 Source/HBIOS/cfg_rcz180.asm |   1 +
 Source/HBIOS/cfg_rcz80.asm  |   1 +
 Source/HBIOS/cfg_sbc.asm    |   1 +
 Source/HBIOS/cfg_scz180.asm |   1 +
 Source/HBIOS/cfg_zeta.asm   |   1 +
 Source/HBIOS/cfg_zeta2.asm  |   1 +
 Source/HBIOS/sn76489.asm    |  37 +---
 14 files changed, 122 insertions(+), 344 deletions(-)

diff --git a/Source/HBIOS/audio.inc b/Source/HBIOS/audio.inc
index 09469326..a3ca68da 100644
--- a/Source/HBIOS/audio.inc
+++ b/Source/HBIOS/audio.inc
@@ -30,3 +30,46 @@
 
 #DEFINE AUDTRACE_CR
 #ENDIF
+
+
+#IFNDEF AUDIOUTILS
+#DEFINE AUDIOUTILS
+
+AUD_NOTE:
+	AUDDEBUG("AUDNOTE ")
+	AUDTRACE_HL
+	AUDTRACE_CR
+	AUDTRACE_DE
+	AUDTRACE_CR
+
+	push	de
+	LD	DE, 48
+	CALL	DIV16
+					; BC IS OCTAVE COUNT
+					; HL is NOTE WITIN OCTAVE
+	ADD	HL, HL
+	pop	de
+	ADD	HL, DE
+
+	LD	A, (HL)			; RETRIEVE PERIOD COUNT FROM SN7NOTETBL
+	INC	HL
+	LD	H, (HL)
+	LD	L, A
+
+	INC	C
+AUD_NOTE1:
+	DEC	C
+	JR	Z, AUD_NOTE2
+	SRL	H
+  	RR	L
+	JR	AUD_NOTE1
+
+AUD_NOTE2:
+	LD	A, L			; IF NOT ZERO
+	OR	H
+	RET	NZ			; RETURN THE CALCULATED PERIOD
+
+	LD	H, $FF			; OTHERWISE RETURN -1 PERIOD (ERROR)
+	LD	L, $FF
+	RET
+#ENDIF
\ No newline at end of file
diff --git a/Source/HBIOS/ay38910.asm b/Source/HBIOS/ay38910.asm
index fcb591a1..7f712f09 100644
--- a/Source/HBIOS/ay38910.asm
+++ b/Source/HBIOS/ay38910.asm
@@ -72,8 +72,6 @@ AY_NOISECNT	.EQU	1		; COUNT NUMBER OF NOISE CHANNELS
 AY_PHICLK	.EQU	3579545		; MSX NTSC COLOUR BURST FREQ = 315/88
 ;AY_PHICLK	.EQU	3500000		; ZX SPECTRUM 3.5MHZ
 ;AY_PHICLK	.EQU	4000000		; RETROBREW SCB-SCG
-AY_CLKDIV	.EQU	2
-AY_CLK		.EQU	AY_PHICLK / AY_CLKDIV
 AY_RATIO	.EQU	AY_CLK * 100 / 16
 ;
 #INCLUDE "audio.inc"
@@ -199,6 +197,19 @@ AY_VOLUME:
 	RET
 ;
 ;======================================================================
+;	SOUND DRIVER FUNCTION - NOTE
+;======================================================================
+;
+AY_NOTE:
+	AUDTRACE(AYT_NOTE)
+	AUDTRACE_HL
+	AUDTRACE_CR
+
+	LD	DE, AY3NOTETBL
+	CALL	AUD_NOTE		; RETURNS PERIOD IN HL, FALL THRU
+					; TO SET THIS PERIOD
+;
+;======================================================================
 ;	SOUND DRIVER FUNCTION - PERIOD
 ;======================================================================
 ;
@@ -220,45 +231,6 @@ AY_PERIOD1:
 	RET				; AND RETURN FAILURE
 ;
 ;======================================================================
-;	SOUND DRIVER FUNCTION - NOTE
-;======================================================================
-;
-AY_NOTE:
-	AUDTRACE(AYT_NOTE)
-	AUDTRACE_L
-	AUDTRACE_CR
-;
-	PUSH	HL
-	PUSH	DE
-	LD	H,0
-	ADD	HL, HL			; SHIFT RIGHT (MULT 2) -INDEX INTO AY3NOTETBL TABLE OF WORDS
-;					; TEST IF HL IS LARGER THAN AY3NOTETBL SIZE
-;	OR	A			; CLEAR CARRY FLAG
-	LD	DE, SIZ_AY3NOTETBL
-;	SBC	HL, DE
-;	JR	NC, AY_NOTE1		; INCOMING HL DOES NOT MAP INTO AY3NOTETBL
-;
-;	ADD	HL, DE			; RESTORE HL
-	LD	DE, AY3NOTETBL		; HL = AY3NOTETBL + HL
-	ADD	HL, DE
-;
-	LD	A, (HL)			; RETRIEVE PERIOD COUNT FROM AY3NOTETBL
-	INC	HL
-	LD	H, (HL)
-	LD	L, A
-;
-	CALL	AY_PERIOD		; APPLY NOTE PERIOD
-	POP	DE
-	POP	HL
-	RET
-;
-AY_NOTE1:
-	POP	DE
-	POP	HL
-	OR	$FF			; NOT IMPLEMENTED YET
-	RET
-;
-;======================================================================
 ;	SOUND DRIVER FUNCTION - PLAY
 ;	B = FUNCTION
 ;	C = AUDIO DEVICE
@@ -463,271 +435,56 @@ AYT_REGWR		.DB	"\r\nOUT AY-3-8910 $"
 ;	BBC MICRO QUARTER TONE FREQUENCY TABLE
 ;======================================================================
 ;
+; THE FREQUENCY BY QUARTER TONE STARTING AT A0# OCATVE 0
+; USED TO MAP EACH OCTAVE (DIV BY 2 TO JUMP AN OCTAVE UP)
+; FIRST PLAYABLE NOTE WILL BE 0
+; ASSUMING A CLOCK OF 1843200 THIS MAPS TO A0#
 AY3NOTETBL:
-	.DW	AY_RATIO / 5827		; A#1	INDEX 0 = A#1 AS PER BBC MANUAL
-;	.DW	AY_RATIO / 5912
-;	.DW	AY_RATIO / 5998
-;	.DW	AY_RATIO / 6085
-	.DW	AY_RATIO / 6174		; B1	INDEX 1 = B1 AS PER BBC MANUAL
-	.DW	AY_RATIO / 6263
-	.DW	AY_RATIO / 6354
-	.DW	AY_RATIO / 6447
-	.DW	AY_RATIO / 6541		; C2
-	.DW	AY_RATIO / 6636
-	.DW	AY_RATIO / 6732
-	.DW	AY_RATIO / 6830
-	.DW	AY_RATIO / 6930		; C#2
-	.DW	AY_RATIO / 7030
-	.DW	AY_RATIO / 7133
-	.DW	AY_RATIO / 7236
-	.DW	AY_RATIO / 7342		; D2
-	.DW	AY_RATIO / 7448
-	.DW	AY_RATIO / 7557
-	.DW	AY_RATIO / 7667
-	.DW	AY_RATIO / 7778		; D#2
-	.DW	AY_RATIO / 7891
-	.DW	AY_RATIO / 8006
-	.DW	AY_RATIO / 8123
-	.DW	AY_RATIO / 8241		; E2
-	.DW	AY_RATIO / 8361
-	.DW	AY_RATIO / 8482
-	.DW	AY_RATIO / 8606
-	.DW	AY_RATIO / 8731 	; F2
-	.DW	AY_RATIO / 8858
-	.DW	AY_RATIO / 8987
-	.DW	AY_RATIO / 9117
-	.DW	AY_RATIO / 9250		; F#2
-	.DW	AY_RATIO / 9384
-	.DW	AY_RATIO / 9521
-	.DW	AY_RATIO / 9659
-	.DW	AY_RATIO / 9800 	; G2
-	.DW	AY_RATIO / 9942
-	.DW	AY_RATIO / 10087
-	.DW	AY_RATIO / 10234
-	.DW	AY_RATIO / 10383	; G#2
-	.DW	AY_RATIO / 10534
-	.DW	AY_RATIO / 10687
-	.DW	AY_RATIO / 10842
-	.DW	AY_RATIO / 11000	; A2
-	.DW	AY_RATIO / 11160
-	.DW	AY_RATIO / 11322
-	.DW	AY_RATIO / 11487
-	.DW	AY_RATIO / 11654	; A#2
-	.DW	AY_RATIO / 11824
-	.DW	AY_RATIO / 11996
-	.DW	AY_RATIO / 12170
-	.DW	AY_RATIO / 12347	; B2
-	.DW	AY_RATIO / 12527
-	.DW	AY_RATIO / 12709
-	.DW	AY_RATIO / 12894
-	.DW	AY_RATIO / 13081	; C3
-	.DW	AY_RATIO / 13272
-	.DW	AY_RATIO / 13465
-	.DW	AY_RATIO / 13660
-	.DW	AY_RATIO / 13859	; C#3
-	.DW	AY_RATIO / 14061
-	.DW	AY_RATIO / 14265
-	.DW	AY_RATIO / 14473
-	.DW	AY_RATIO / 14683	; D3
-	.DW	AY_RATIO / 14897
-	.DW	AY_RATIO / 15113
-	.DW	AY_RATIO / 15333
-	.DW	AY_RATIO / 15556	; D#3
-	.DW	AY_RATIO / 15783
-	.DW	AY_RATIO / 16012
-	.DW	AY_RATIO / 16245
-	.DW	AY_RATIO / 16481	; E3
-	.DW	AY_RATIO / 16721
-	.DW	AY_RATIO / 16964
-	.DW	AY_RATIO / 17211
-	.DW	AY_RATIO / 17461	; F3
-	.DW	AY_RATIO / 17715
-	.DW	AY_RATIO / 17973
-	.DW	AY_RATIO / 18234
-	.DW	AY_RATIO / 18500	; F#3
-	.DW	AY_RATIO / 18769
-	.DW	AY_RATIO / 19042
-	.DW	AY_RATIO / 19319
-	.DW	AY_RATIO / 19600	; G3
-	.DW	AY_RATIO / 19885
-	.DW	AY_RATIO / 20174
-	.DW	AY_RATIO / 20468
-	.DW	AY_RATIO / 20765	; G#3
-	.DW	AY_RATIO / 21067
-	.DW	AY_RATIO / 21374
-	.DW	AY_RATIO / 21685
-	.DW	AY_RATIO / 22000	; A3
-	.DW	AY_RATIO / 22320
-	.DW	AY_RATIO / 22645
-	.DW	AY_RATIO / 22974
-	.DW	AY_RATIO / 23308	; A#3
-	.DW	AY_RATIO / 23647
-	.DW	AY_RATIO / 23991
-	.DW	AY_RATIO / 24340
-	.DW	AY_RATIO / 24694	; B3
-	.DW	AY_RATIO / 25053
-	.DW	AY_RATIO / 25418
-	.DW	AY_RATIO / 25787
-	.DW	AY_RATIO / 26163	; C4
-	.DW	AY_RATIO / 26543
-	.DW	AY_RATIO / 26929
-	.DW	AY_RATIO / 27321
-	.DW	AY_RATIO / 27718	; C#4
-	.DW	AY_RATIO / 28121
-	.DW	AY_RATIO / 28530
-	.DW	AY_RATIO / 28945
-	.DW	AY_RATIO / 29366	; D4
-	.DW	AY_RATIO / 29794
-	.DW	AY_RATIO / 30227
-	.DW	AY_RATIO / 30667
-	.DW	AY_RATIO / 31113	; D#4
-	.DW	AY_RATIO / 31565
-	.DW	AY_RATIO / 32024
-	.DW	AY_RATIO / 32490
-	.DW	AY_RATIO / 32963	; E4
-	.DW	AY_RATIO / 33442
-	.DW	AY_RATIO / 33929
-	.DW	AY_RATIO / 34422
-	.DW	AY_RATIO / 34923	; F4
-	.DW	AY_RATIO / 35431
-	.DW	AY_RATIO / 35946
-	.DW	AY_RATIO / 36469
-	.DW	AY_RATIO / 36999	; F#4
-	.DW	AY_RATIO / 37538
-	.DW	AY_RATIO / 38084
-	.DW	AY_RATIO / 38638
-	.DW	AY_RATIO / 39200	; G4
-	.DW	AY_RATIO / 39770
-	.DW	AY_RATIO / 40348
-	.DW	AY_RATIO / 40935
-	.DW	AY_RATIO / 41530	; G#4
-	.DW	AY_RATIO / 42135
-	.DW	AY_RATIO / 42747
-	.DW	AY_RATIO / 43369
-	.DW	AY_RATIO / 44000	; A4
-	.DW	AY_RATIO / 44640
-	.DW	AY_RATIO / 45289
-	.DW	AY_RATIO / 45948
-	.DW	AY_RATIO / 46616	; A#4
-	.DW	AY_RATIO / 47294
-	.DW	AY_RATIO / 47982
-	.DW	AY_RATIO / 48680
-	.DW	AY_RATIO / 49388	; B4
-	.DW	AY_RATIO / 50107
-	.DW	AY_RATIO / 50836
-	.DW	AY_RATIO / 51575
-	.DW	AY_RATIO / 52325	; C5
-	.DW	AY_RATIO / 53086
-	.DW	AY_RATIO / 53858
-	.DW	AY_RATIO / 54642
-	.DW	AY_RATIO / 55437	; C#5
-	.DW	AY_RATIO / 56243
-	.DW	AY_RATIO / 57061
-	.DW	AY_RATIO / 57891
-	.DW	AY_RATIO / 58733	; D5
-	.DW	AY_RATIO / 59587
-	.DW	AY_RATIO / 60454
-	.DW	AY_RATIO / 61333
-	.DW	AY_RATIO / 62225	; D#5
-	.DW	AY_RATIO / 63130
-	.DW	AY_RATIO / 64049
-	.DW	AY_RATIO / 64980
-	.DW	AY_RATIO / 65926	; E5
-	.DW	AY_RATIO / 66884
-	.DW	AY_RATIO / 67857
-	.DW	AY_RATIO / 68844
-	.DW	AY_RATIO / 69846	; F5
-	.DW	AY_RATIO / 70862
-	.DW	AY_RATIO / 71892
-	.DW	AY_RATIO / 72938
-	.DW	AY_RATIO / 73999	; F#5
-	.DW	AY_RATIO / 75075
-	.DW	AY_RATIO / 76167
-	.DW	AY_RATIO / 77275
-	.DW	AY_RATIO / 78399	; G5
-	.DW	AY_RATIO / 79539
-	.DW	AY_RATIO / 80696
-	.DW	AY_RATIO / 81870
-	.DW	AY_RATIO / 83061	; G#5
-	.DW	AY_RATIO / 84269
-	.DW	AY_RATIO / 85495
-	.DW	AY_RATIO / 86738
-	.DW	AY_RATIO / 88000	; #A5
-	.DW	AY_RATIO / 89280
-	.DW	AY_RATIO / 90579
-	.DW	AY_RATIO / 91896
-	.DW	AY_RATIO / 93233	; A#5
-	.DW	AY_RATIO / 94589
-	.DW	AY_RATIO / 95965
-	.DW	AY_RATIO / 97361
-	.DW	AY_RATIO / 98777	; B5
-	.DW	AY_RATIO / 100213
-	.DW	AY_RATIO / 101671
-	.DW	AY_RATIO / 103150
-	.DW	AY_RATIO / 104650	; C6
-	.DW	AY_RATIO / 106172
-	.DW	AY_RATIO / 107717
-	.DW	AY_RATIO / 109283
-	.DW	AY_RATIO / 110873	; C#6
-	.DW	AY_RATIO / 112486
-	.DW	AY_RATIO / 114122
-	.DW	AY_RATIO / 115782
-	.DW	AY_RATIO / 117466	; D6
-	.DW	AY_RATIO / 119174
-	.DW	AY_RATIO / 120908
-	.DW	AY_RATIO / 122667
-	.DW	AY_RATIO / 124451	; D#6
-	.DW	AY_RATIO / 126261
-	.DW	AY_RATIO / 128097
-	.DW	AY_RATIO / 129961
-	.DW	AY_RATIO / 131851	; E6
-	.DW	AY_RATIO / 133769
-	.DW	AY_RATIO / 135715
-	.DW	AY_RATIO / 137689
-	.DW	AY_RATIO / 139691	; F6
-	.DW	AY_RATIO / 141723
-	.DW	AY_RATIO / 143785
-	.DW	AY_RATIO / 145876
-	.DW	AY_RATIO / 147998	; F#6
-	.DW	AY_RATIO / 150150
-	.DW	AY_RATIO / 152334
-	.DW	AY_RATIO / 154550
-	.DW	AY_RATIO / 156798	; G6
-	.DW	AY_RATIO / 159079
-	.DW	AY_RATIO / 161393
-	.DW	AY_RATIO / 163740
-	.DW	AY_RATIO / 166122	; G#6
-	.DW	AY_RATIO / 168538
-	.DW	AY_RATIO / 170990
-	.DW	AY_RATIO / 173477
-	.DW	AY_RATIO / 176000	; A6
-	.DW	AY_RATIO / 178560
-	.DW	AY_RATIO / 181157
-	.DW	AY_RATIO / 183792
-	.DW	AY_RATIO / 186466	; A#6
-	.DW	AY_RATIO / 189178
-	.DW	AY_RATIO / 191929
-	.DW	AY_RATIO / 194721
-	.DW	AY_RATIO / 197553	; B6
-	.DW	AY_RATIO / 200427
-	.DW	AY_RATIO / 203342
-	.DW	AY_RATIO / 206300
-	.DW	AY_RATIO / 209300	; C7
-	.DW	AY_RATIO / 212345
-	.DW	AY_RATIO / 215433
-	.DW	AY_RATIO / 218567
-	.DW	AY_RATIO / 221746	; C#7
-	.DW	AY_RATIO / 224971
-	.DW	AY_RATIO / 228244
-	.DW	AY_RATIO / 231564
-	.DW	AY_RATIO / 234932	; D7
-	.DW	AY_RATIO / 238349
-	.DW	AY_RATIO / 241816
-
-SIZ_AY3NOTETBL	.EQU	$ - AY3NOTETBL
-		.ECHO	"AY-3-8910 approx "
-		.ECHO	SIZ_AY3NOTETBL / 2 / 4 / 12
-		.ECHO	" Octaves.  Last note index supported: "
-
-		.ECHO SIZ_AY3NOTETBL / 2
-		.ECHO "\n"
+	.DW	AY_RATIO / 2913
+	.DW	AY_RATIO / 2956
+	.DW	AY_RATIO / 2999
+	.DW	AY_RATIO / 3042
+	.DW	AY_RATIO / 3086
+	.DW	AY_RATIO / 3131
+	.DW	AY_RATIO / 3177
+	.DW	AY_RATIO / 3223
+	.DW	AY_RATIO / 3270
+	.DW	AY_RATIO / 3318
+	.DW	AY_RATIO / 3366
+	.DW	AY_RATIO / 3415
+	.DW	AY_RATIO / 3464
+	.DW	AY_RATIO / 3515
+	.DW	AY_RATIO / 3566
+	.DW	AY_RATIO / 3618
+	.DW	AY_RATIO / 3670
+	.DW	AY_RATIO / 3724
+	.DW	AY_RATIO / 3778
+	.DW	AY_RATIO / 3833
+	.DW	AY_RATIO / 3889
+	.DW	AY_RATIO / 3945
+	.DW	AY_RATIO / 4003
+	.DW	AY_RATIO / 4061
+	.DW	AY_RATIO / 4120
+	.DW	AY_RATIO / 4180
+	.DW	AY_RATIO / 4241
+	.DW	AY_RATIO / 4302
+	.DW	AY_RATIO / 4365
+	.DW	AY_RATIO / 4428
+	.DW	AY_RATIO / 4493
+	.DW	AY_RATIO / 4558
+	.DW	AY_RATIO / 4624
+	.DW	AY_RATIO / 4692
+	.DW	AY_RATIO / 4760
+	.DW	AY_RATIO / 4829
+	.DW	AY_RATIO / 4899
+	.DW	AY_RATIO / 4971
+	.DW	AY_RATIO / 5043
+	.DW	AY_RATIO / 5116
+	.DW	AY_RATIO / 5191
+	.DW	AY_RATIO / 5266
+	.DW	AY_RATIO / 5343
+	.DW	AY_RATIO / 5421
+	.DW	AY_RATIO / 5499
+	.DW	AY_RATIO / 5579
+	.DW	AY_RATIO / 5661
+	.DW	AY_RATIO / 5743
diff --git a/Source/HBIOS/cfg_dyno.asm b/Source/HBIOS/cfg_dyno.asm
index c0c936a3..577dd712 100644
--- a/Source/HBIOS/cfg_dyno.asm
+++ b/Source/HBIOS/cfg_dyno.asm
@@ -158,5 +158,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_RCZ180	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
-SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
+SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
\ No newline at end of file
diff --git a/Source/HBIOS/cfg_ezz80.asm b/Source/HBIOS/cfg_ezz80.asm
index 2ea3df23..d604eb3e 100644
--- a/Source/HBIOS/cfg_ezz80.asm
+++ b/Source/HBIOS/cfg_ezz80.asm
@@ -183,5 +183,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_RCZ80	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_master.asm b/Source/HBIOS/cfg_master.asm
index f46779c8..2b1baa7c 100644
--- a/Source/HBIOS/cfg_master.asm
+++ b/Source/HBIOS/cfg_master.asm
@@ -238,5 +238,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_NONE	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index fc316e15..8889fd05 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -192,5 +192,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_SCG	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index 88069943..700fc0f7 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -192,5 +192,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	TRUE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_N8	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_rcz180.asm b/Source/HBIOS/cfg_rcz180.asm
index ebc473e2..2e77375b 100644
--- a/Source/HBIOS/cfg_rcz180.asm
+++ b/Source/HBIOS/cfg_rcz180.asm
@@ -192,5 +192,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_RCZ180	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_rcz80.asm b/Source/HBIOS/cfg_rcz80.asm
index dfd4d72a..f4480f94 100644
--- a/Source/HBIOS/cfg_rcz80.asm
+++ b/Source/HBIOS/cfg_rcz80.asm
@@ -198,5 +198,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_RCZ80	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_sbc.asm b/Source/HBIOS/cfg_sbc.asm
index c37f0ef4..650d4eae 100644
--- a/Source/HBIOS/cfg_sbc.asm
+++ b/Source/HBIOS/cfg_sbc.asm
@@ -194,5 +194,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_SCG	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_scz180.asm b/Source/HBIOS/cfg_scz180.asm
index 68fbccf6..dcc39d72 100644
--- a/Source/HBIOS/cfg_scz180.asm
+++ b/Source/HBIOS/cfg_scz180.asm
@@ -187,5 +187,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_RCZ180	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_zeta.asm b/Source/HBIOS/cfg_zeta.asm
index 2d9cce1e..14d8770e 100644
--- a/Source/HBIOS/cfg_zeta.asm
+++ b/Source/HBIOS/cfg_zeta.asm
@@ -139,5 +139,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_NONE	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/cfg_zeta2.asm b/Source/HBIOS/cfg_zeta2.asm
index fbbaf6ac..1901511d 100644
--- a/Source/HBIOS/cfg_zeta2.asm
+++ b/Source/HBIOS/cfg_zeta2.asm
@@ -149,5 +149,6 @@ SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
 SN7CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 
 AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+AY_CLK		.EQU	CPUOSC / 4	; DEFAULT TO CPUOSC / 4
 AYMODE		.EQU	AYMODE_NONE	; AY: DRIVER MODE: AYMODE_[SCG/N8/RCZ80/RCZ180]
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index cb062d53..5237aac4 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -105,40 +105,9 @@ SN7_VOLUME:
 	RET
 
 SN7_NOTE:
-	AUDTRACE(SNT_NOTE)
-	AUDTRACE_HL
-	AUDTRACE_CR
-
-	LD	DE, 48
-	CALL	DIV16
-					; BC IS OCTAVE COUNT
-					; HL is NOTE WITIN OCTAVE
-	ADD	HL, HL
 	LD	DE, SN7NOTETBL
-	ADD	HL, DE
-
-	LD	A, (HL)			; RETRIEVE PERIOD COUNT FROM SN7NOTETBL
-	INC	HL
-	LD	H, (HL)
-	LD	L, A
-
-	INC	C
-SN7_NOTE1:
-	DEC	C
-	JR	Z, SN7_NOTE2
-	SRL	H
-  	RR	L
-	JR	SN7_NOTE1
-
-SN7_NOTE2:
-	LD	A, L			; IF WE GENERATE ZERO - RETURN ERROR
-	OR	H
-	JR	NZ, SN7_PERIOD		; OTHERWISE APPLY THE CALCULATED PERIOD
-
-	LD	H, $FF
-	LD	L, $FF
-	JR	SN7_PERIOD
-
+	CALL	AUD_NOTE		; RETURNS PERIOD IN HL, FALL THRU
+					; TO SET THIS PERIOD
 SN7_PERIOD:
 	AUDTRACE(SNT_PERIOD)
 	AUDTRACE_HL
@@ -421,5 +390,3 @@ SN7NOTETBL:
 	.DW	SN7RATIO / 5579
 	.DW	SN7RATIO / 5661
 	.DW	SN7RATIO / 5743
-
-SIZ_SN7NOTETBL	.EQU	$ - SN7NOTETBL

From ab84a43d33ef1c1b2fd43d535d48610862ecd6a4 Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sun, 10 May 2020 13:52:51 +1000
Subject: [PATCH 6/7] Sound drivers: support/rejection of zero value for period

SN76489:
The SN76489 chip will produce a note for value 0 - but the driver will reject
this value - but it does allow value $400 - (logically the same) to produce the lowest note

AY38910:
This chip does not produce a sound for period of 0 - so its also rejected
The max value for this driver is still $0FFF
---
 Source/HBIOS/ay38910.asm |  6 +++++-
 Source/HBIOS/sn76489.asm | 15 ++++++---------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/Source/HBIOS/ay38910.asm b/Source/HBIOS/ay38910.asm
index 7f712f09..01dc90a5 100644
--- a/Source/HBIOS/ay38910.asm
+++ b/Source/HBIOS/ay38910.asm
@@ -217,7 +217,11 @@ AY_PERIOD:
 	AUDTRACE(AYT_PERIOD)
 	AUDTRACE_HL
 	AUDTRACE_CR
-;
+
+	LD	A, H			; IF ZERO - ERROR
+	OR	L
+	JR	Z, AY_PERIOD1
+
 	LD	A, H			; MAXIMUM TONE PERIOD IS 12-BITS
 	AND	11110000B		; ALLOWED RANGE IS 0001-0FFF (4095)
 	JR	NZ, AY_PERIOD1		; RETURN NZ IF NUMBER TOO LARGE
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index 5237aac4..56aaaecc 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -113,11 +113,9 @@ SN7_PERIOD:
 	AUDTRACE_HL
 	AUDTRACE_CR
 
-	; TODO: MAKE ZERO BE AN INVALID VALUE (USE 400) TO INDICATE LOWEST NOTE
-	; NEED TO UPDATE TUNE.ASM TO SUPPORT THIS?
-	; LD	A, H			; IF ZERO - ERROR
-	; OR	L
-	; JR	Z, SN7_QUERY_PERIOD1
+	LD	A, H			; IF ZERO - ERROR
+	OR	L
+	JR	Z, SN7_QUERY_PERIOD1
 
 	LD	(SN7_PENDING_PERIOD), HL ;ASSUME SUCCESS
 
@@ -130,11 +128,10 @@ SN7_PERIOD:
 	RET
 
 SN7_QUERY_PERIOD1:			; REQUESTED PERIOD IS LARGER THAN THE SN76489 CAN SUPPORT
-	LD	L, $FF
-	LD	H, $FF
+	LD	A, $FF
+	LD	L, A
+	LD	H, A
 	LD	(SN7_PENDING_PERIOD), HL
-
-	OR	$FF			; SIGNAL FAILURE
 	RET
 
 SN7_PLAY:

From 45cd12b77e45336ddc2da0493bf742d679b5c465 Mon Sep 17 00:00:00 2001
From: Dean Netherton <dean.netherton@gmail.com>
Date: Sun, 10 May 2020 14:08:34 +1000
Subject: [PATCH 7/7] Sn76489: Updated todo list

---
 Source/HBIOS/sn76489.asm | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index 56aaaecc..220e07e3 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -6,8 +6,7 @@
 ;
 ; TODO:
 ; 1. PROVIDE SUPPORT FOR NOISE CHANNEL
-; 2. FOR PERIOD SET, MAP 400 TO 0 AND RETURN ERROR FOR 000
-; 3. DOES THIS WORK FOR FASTER CPUS? ONLY BEEN TEST ON A Z80 7MHZ UNIT
+; 2. DOES THIS WORK FOR FASTER CPUS? ONLY BEEN TESTED ON A Z80 7MHZ UNIT
 ;
 ;======================================================================
 ; CONSTANTS