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 "