diff --git a/Source/Apps/Tune/Tune.asm b/Source/Apps/Tune/Tune.asm
index 6f340a2e..fc41b087 100644
--- a/Source/Apps/Tune/Tune.asm
+++ b/Source/Apps/Tune/Tune.asm
@@ -40,6 +40,7 @@
 ;   2020-02-11 [WBW] Made hardware config & detection more flexible
 ;   2020-03-29 [WBW] Fix error in Z180 I/O W/S bracketing
 ;   2020-04-25 [DEN] Added support to use HBIOS Sound driver
+;   2020-05-02 [PMS] Add support for SBC-V2 slow-io hack
 ;_______________________________________________________________________________
 ;
 ; ToDo:
@@ -53,14 +54,18 @@
 #include	"hbios.inc"
 #include	"cpm.inc"
 #include	"tune.inc"
-
+;
 HEAPEND		.EQU	$C000		; End of heap storage
 ;
 TYPPT2		.EQU	1		; FILTYP value for PT2 sound file
 TYPPT3		.EQU	2		; FILTYP value for PT3 sound file
 TYPMYM		.EQU	3		; FILTYP value for MYM sound file
 ;
-
+; HIGH SPEED CPU CONTROL
+;
+SBCV2004	.EQU	0		; USE SBC-V2-004 HALF CLOCK DIVIDER
+CPUFAMZ180	.EQU	1		; USE Z180 WAIT STATE MANAGEMENT
+;
 ;Conditional assembly - use  -D switch on TASM or uz80as assembler to control
 _ZX		.EQU    0		; 1) Version of ROUT (ZX or MSX standards)
 _MSX		.EQU    0
@@ -401,43 +406,44 @@ IDBIO2:
 ;
 ;
 ;
-SLOWCPU:
-	LD A,(Z180)	; Z180 base I/O port
-	CP $FF		; Check for no value
-	RET Z		; Bail out if no value
-	ADD A,$1E	; Apply offset of CMR register
-	LD C,A		; And put it in C
-	LD B,0		; MSB for 16-bit I/O
-	IN A,(C)	; Get current value
-	LD (CMRSAV),A	; Save it to restore later
-	XOR A		; Go slow
-	OUT (C),A	; And update CMR
-	INC C		; Now point to CCR register
-	IN A,(C)	; Get current value
-	LD (CCRSAV),A	; Save it to restore later
-	XOR A		; Go slow
-	OUT (C),A	; And update CCR
-	RET
-;
-;
-;
-NORMCPU:
-	LD A,(Z180)	; Z180 base I/O port
-	CP $FF		; Check for no value
-	RET Z		; Bail out if no value
-	ADD A,$1E	; Apply offset of CMR register
-	LD C,A		; And put it in C
-	LD B,0		; MSB for 16-bit I/O
-	LD A,(CMRSAV)	; Get original CMR value
-	OUT (C),A	; And update CMR
-	INC C		; Now point to CCR register
-	LD A,(CCRSAV)	; Get original CCR value
-	OUT (C),A	; And update CCR
-	RET
-;
-;
+;SLOWCPU:
+;	LD A,(Z180)	; Z180 base I/O port
+;	CP $FF		; Check for no value
+;	RET Z		; Bail out if no value
+;	ADD A,$1E	; Apply offset of CMR register
+;	LD C,A		; And put it in C
+;	LD B,0		; MSB for 16-bit I/O
+;	IN A,(C)	; Get current value
+;	LD (CMRSAV),A	; Save it to restore later
+;	XOR A		; Go slow
+;	OUT (C),A	; And update CMR
+;	INC C		; Now point to CCR register
+;	IN A,(C)	; Get current value
+;	LD (CCRSAV),A	; Save it to restore later
+;	XOR A		; Go slow
+;	OUT (C),A	; And update CCR
+;	RET
+;
+;
+;
+;NORMCPU:
+;	LD A,(Z180)	; Z180 base I/O port
+;	CP $FF		; Check for no value
+;	RET Z		; Bail out if no value
+;	ADD A,$1E	; Apply offset of CMR register
+;	LD C,A		; And put it in C
+;	LD B,0		; MSB for 16-bit I/O
+;	LD A,(CMRSAV)	; Get original CMR value
+;	OUT (C),A	; And update CMR
+;	INC C		; Now point to CCR register
+;	LD A,(CCRSAV)	; Get original CCR value
+;	OUT (C),A	; And update CCR
+;	RET
+;
+;	SLOW DOWN I/O FOR FAST CPU'S
 ;
 SLOWIO:
+#IF (CPUFAMZ180)
 	LD A,(Z180)	; Z180 base I/O port
 	CP $FF		; Check for no value
 	RET Z		; Bail out if no value
@@ -448,11 +454,17 @@ SLOWIO:
 	LD (DCSAV),A	; Save it to restore later
 	OR %00110000	; Force slow operation (I/O W/S=3)
 	OUT (C),A	; And update DCNTL
+#ENDIF
+#IF (SBCV2004)
+	LD A,8		; sbc-v2-004 change to
+	OUT (112),A	; half clock speed
+#ENDIF
 	RET
 ;
-;
+;	RESTORE I/O SPEED FOR FAST CPU'S
 ;
 NORMIO:
+#IF (CPUFAMZ180)
 	LD A,(Z180)	; Z180 base I/O port
 	CP $FF		; Check for no value
 	RET Z		; Bail out if no value
@@ -461,8 +473,12 @@ NORMIO:
 	LD B,0		; MSB for 16-bit I/O
 	LD A,(DCSAV)	; Get saved DCNTL value
 	OUT (C),A	; And restore it
+#ENDIF
+#IF (SBCV2004)
+	LD A,0		; sbc-v2-004 change to
+	OUT (112),A	; normal clock speed
+#ENDIF
 	RET
-
 ;
 ERRBIO:	; Invalid BIOS or version
 	LD	DE,MSGBIO
@@ -1982,87 +1998,93 @@ LOUT	OUT 	(C), A		; SELECT REGISTER
 	JP 	M, LOUT2	; IF BIT 7 SET, RETURN W/O WRITING VALUE
 	LD 	C, D		; SELECT DATA PORT
 	OUT 	(C), A		; WRITE VALUE TO REGISTER 13
-LOUT2
-	CALL 	NORMIO
+LOUT2	CALL 	NORMIO
 	EI
 	RET			; AND DONE
 
 PLAYVIAHBIOS:
-	LD	B, BF_SNDVOL
-	LD	C, 0
-	LD	H, 0
-	LD	A, (AYREGS + AmplA)
-	AND	$0F
-	rlca
-	rlca
-	rlca
-	rlca
+;
+;	CHANNEL 0 (LEFT)
+;
+	LD	B, BF_SNDVOL		; SET VOLUME
+	LD	C, 0			; DEVICE 0
+;	LD	H, 0
+	LD	A, (AYREGS + AmplA)	; GET 4-BIT 
+	AND	$0F			; VOLUME 0-15	
+	RLCA				; AND CONVERT
+	RLCA				; TO HBIOS	
+	RLCA				; RANGE 0-255
+	RLCA
 	LD	L, A
 	RST	08
-
-	LD	B, BF_SNDPRD
-	LD	C, 0
-	LD	HL, (AYREGS+TonA)
-	ld	a, h
-	AND	$0F
+;
+	LD	B, BF_SNDPRD		; SET PERIOD
+	LD	C, 0			; DEVICE 0
+	LD	HL, (AYREGS+TonA)	; GET 12-BIT TONE PERIOD
+	ld	A, H			; MASK OFF HIGH
+	AND	$0F			; NIBBLE 
 	LD	H, A
 	RST	08
-
-	LD	B, BF_SNDPLAY
-	LD	C, 0
-	LD	D, 0
+;
+	LD	B, BF_SNDPLAY		; PLAY
+	LD	C, 0			; DEVICE 0
+	LD	D, 0			; CHANNEL 0
 	RST	08
-
-	LD	B, BF_SNDVOL
-	LD	C, 0
-	LD	H, 0
-	LD	A, (AYREGS + AmplB)
-	AND	$0F
-	rlca
-	rlca
-	rlca
-	rlca
+;
+;	CHANNEL 1 (MIDDLE)
+;
+	LD	B, BF_SNDVOL		; SET VOLUME
+	LD	C, 0			; DEVICE 0
+;	LD	H, 0
+	LD	A, (AYREGS + AmplB)	; GET 4-BIT 
+	AND	$0F                	; VOLUME 0-15	
+	RLCA                       	; AND CONVERT
+	RLCA                       	; TO HBIOS	
+	RLCA                       	; RANGE 0-255
+	RLCA
 	LD	L, A
 	RST	08
-
-	LD	B, BF_SNDPRD
-	LD	C, 0
-	LD	HL, (AYREGS+TonB)
-	ld	a, h
-	AND	$0F
+;
+	LD	B, BF_SNDPRD		; SET PERIOD
+	LD	C, 0			; DEVICE 0
+	LD	HL, (AYREGS+TonB)       ; GET 12-BIT ONE PERIOD
+	ld	a, h                    ; MASK OFF HIGH
+	AND	$0F                     ; NIBBLE 
 	LD	H, A
 	RST	08
-
-	LD	B, BF_SNDPLAY
-	LD	C, 0
-	LD	D, 1
+;
+	LD	B, BF_SNDPLAY		; PLAY
+	LD	C, 0         		; DEVICE 0
+	LD	D, 1         		; CHANNEL 1
 	RST	08
-
-	LD	B, BF_SNDVOL
-	LD	C, 0
-	LD	H, 0
-	LD	A, (AYREGS + AmplC)
-	AND	$0F
-	rlca
-	rlca
-	rlca
-	rlca
+;
+;	CHANNEL 2 (RIGHT)
+;
+	LD	B, BF_SNDVOL		; SET VOLUME
+	LD	C, 0        		; DEVICE 0
+;	LD	H, 0
+	LD	A, (AYREGS + AmplC)	; GET 4-BIT 
+	AND	$0F                	; VOLUME 0-15	
+	RLCA                       	; AND CONVERT
+	RLCA                       	; TO HBIOS	
+	RLCA                       	; RANGE 0-255
+	RLCA
 	LD	L, A
 	RST	08
-
-	LD	B, BF_SNDPRD
-	LD	C, 0
-	LD	HL, (AYREGS+TonC)
-	ld	a, h
-	AND	$0F
+;
+	LD	B, BF_SNDPRD		; SET PERIOD
+	LD	C, 0        		; DEVICE 0
+	LD	HL, (AYREGS+TonC)	; GET 12-BIT ONE PERIOD
+	ld	A, H       		; MASK OFF HIGH
+	AND	$0F         		; NIBBLE 
 	LD	H, A
 	RST	08
-
-	LD	B, BF_SNDPLAY
-	LD	C, 0
-	LD	D, 2
-	RST	08
-
+;
+	LD	B, BF_SNDPLAY		; PLAY
+	LD	C, 0         		; DEVICE 0
+	LD	D, 2         		; CHANNEL 2
+	RST	08           		; HBIOS CALL
+	
 	RET
 #ENDIF
 
diff --git a/Source/Doc/Architecture.md b/Source/Doc/Architecture.md
index 9d61590f..1d430e74 100644
--- a/Source/Doc/Architecture.md
+++ b/Source/Doc/Architecture.md
@@ -1404,7 +1404,7 @@ The value corresponds to standard musical notes.  The value allows
 for selection of a quarter of a semitone by giving a value between 0
 and up to the drivers maximum supported value. The lowest note is (0).
 
-For the SN76490 chip, 0 corresponds to note A1# and the value 249 is
+For the SN76489 chip, 0 corresponds to note A1# and the value 249 is
 the maximum supported value, and it corresponds to note C7.
 
 ### Function 0x54 -- Sound Play (SNDPLAY)
@@ -1412,7 +1412,7 @@ the maximum supported value, and it corresponds to note C7.
 | _Entry Parameters_
 |       B: 0x54
 |       C: Audio Device Unit ID
-|       E: Channel
+|       D: Channel
 
 |      _Returned Values_
 |           A: Status (0=OK, else error)
@@ -1433,7 +1433,7 @@ HBIOS B=54 C=00 D=01      ; Play note on Channel 1
 ### Function 0x55 -- Sound Query (SNDQUERY)
 
 | _Entry Parameters_
-|       B: 0x54
+|       B: 0x55
 |       C: Audio Device Unit ID
 |       E: Subfunction
 
@@ -1446,7 +1446,7 @@ key aspects of the specific Audio Device.
 #### SNDQUERY Subfunction 0x01 -- Get count of audio channels supported (SNDQ_CHCNT)
 
 |      _Entry Parameters_
-|           B: 0x54
+|           B: 0x55
 |           E: 0x01
 
 |      _Returned Values_
@@ -1454,10 +1454,10 @@ key aspects of the specific Audio Device.
 |           B: Count of standard tone channels
 |           C: Count of noise tone channels
 
-#### SNDQUERY Subfunction 0x01 -- Get current volume setting (SNDQ_VOL)
+#### SNDQUERY Subfunction 0x02		 -- Get current volume setting (SNDQ_VOL)
 
 |      _Entry Parameters_
-|           B: 0x54
+|           B: 0x55
 |           E: 0x02
 
 |      _Returned Values_
@@ -1468,7 +1468,7 @@ key aspects of the specific Audio Device.
 #### SNDQUERY Subfunction 0x03 -- Get current period setting (SNDQ_PERIOD)
 
 |      _Entry Parameters_
-|           B: 0x54
+|           B: 0x55
 |           E: 0x03
 
 |      _Returned Values_
@@ -1478,7 +1478,7 @@ key aspects of the specific Audio Device.
 #### SNDQUERY Subfunction 0x04 -- Get device details (SNDQ_DEV)
 
 |      _Entry Parameters_
-|           B: 0x54
+|           B: 0x55
 |           E: 0x04
 
 |      _Returned Values_
@@ -1502,7 +1502,7 @@ The currently defined audio device types are:
 AUDIO ID       | Value | Device     | Returned registers
 -------------- | ----- | ---------- | --------------------------------------------
 SND_SN76489    | 0x01  | SN76489    | E: Left channel port, L: Right channel port
-SND_SNAY38910  | 0x02  | AY-3-8910  | D: Address port, E: Data port
+SND_AY38910    | 0x02  | AY-3-8910  | D: Address port, E: Data port
 
 
 `\clearpage`{=latex}
diff --git a/Source/HBIOS/ay.asm b/Source/HBIOS/ay.asm
index 85d9b9e2..6c03d2eb 100644
--- a/Source/HBIOS/ay.asm
+++ b/Source/HBIOS/ay.asm
@@ -57,10 +57,10 @@ AY_INIT1:
 	CALL	AY_BEEP
 AY_INIT2:
 	LD	D,AY_R7ENAB		; SET MIXER CONTROL / IO ENABLE
-	LD	E,$FF			; $FF - 11 111 111
-	CALL	AY_WRTPSG		; I/O PORTS DISABLED, NOISE CHANNEL C, B, A DISABLE, TONE CHANNEL C, B, A DISABLE
+	LD	E,$F8			; $FF - 11 111 111
+	CALL	AY_WRTPSG		; I/O PORTS DISABLED, NOISE CHANNEL C, B, A DISABLE, TONE CHANNEL C, B, A ENABLE
 ;  
-	LD	B,2
+	LD	B,3
 	LD	D,AY_R8AVOL		; SET VOLUME TO 0
 	LD	E,$00	
 AY_QUIET:
@@ -73,7 +73,7 @@ AY_QUIET:
 ;	
 AY_BEEP:
 	LD	D,AY_R2CHBP		; SET TONE PERIOD 
-	LD	E,$55			; CHANNEL B  - R00 & R01
+	LD	E,$55			; CHANNEL B  - R02 & R03
 	CALL	AY_WRTPSG		; $0055 = XXXX0000 01010101 
 	LD	D,AY_R3CHBP
 	LD	E,0
@@ -90,7 +90,7 @@ AY_BEEP:
 	CALL	LDELAY			; HALF SECOND 
 	RET	
 ;	
-; WRITE DATA E TO PSG REG A  
+; WRITE DATA E TO PSG REG D  
 ; 
 AY_WRTPSG:
 	HB_DI
@@ -100,10 +100,10 @@ AY_WRTPSG:
 	OR	%00110000		; FORCE SLOW OPERATION (I/O W/S=3)
 	OUT0	(Z180_DCNTL),A		; AND UPDATE DCNTL
 #ENDIF
-	LD	A,D
-	OUT	(AY_RSEL),A
-	LD	A,E
-	OUT	(AY_RDAT),A
+	LD	A,D			; SELECT THE REGISTER WE 
+	OUT	(AY_RSEL),A		; WANT TO WRITE TO
+	LD	A,E			; WRITE THE VALUE TO
+	OUT	(AY_RDAT),A		; THE SELECTED REGISTER
 #IF (CPUFAM == CPU_Z180)
 	POP	AF			; GET SAVED DCNTL VALUE
 	OUT0	(Z180_DCNTL),A		; AND RESTORE IT
diff --git a/Source/HBIOS/ay38910.asm b/Source/HBIOS/ay38910.asm
new file mode 100644
index 00000000..8fe13b25
--- /dev/null
+++ b/Source/HBIOS/ay38910.asm
@@ -0,0 +1,556 @@
+;======================================================================
+;
+;	AY-3-8910 / YM2149 SOUND DRIVER
+;
+;======================================================================
+;
+#IF (AYMODE == AYMODE_SCG)
+AY_RSEL		.EQU	$9A
+AY_RDAT		.EQU	$9B
+AY_ACR		.EQU	$9C
+#ENDIF
+;
+#IF (AYMODE == AYMODE_N8)
+AY_RSEL		.EQU	$9C
+AY_RDAT		.EQU	$9D
+AY_ACR		.EQU	N8_DEFACR
+#ENDIF
+;
+#IF (AYMODE == AYMODE_RCZ80)
+AY_RSEL		.EQU	$D8
+AY_RDAT		.EQU	$D0
+#ENDIF
+;
+#IF (AYMODE == AYMODE_RCZ180)
+AY_RSEL		.EQU	$68
+AY_RDAT		.EQU	$60
+#ENDIF
+;
+;======================================================================
+;
+;	REGISTERS
+;
+AY_R2CHBP	.EQU	$02
+AY_R3CHBP	.EQU	$03
+AY_R7ENAB	.EQU	$07
+AY_R8AVOL	.EQU	$08
+;
+;======================================================================
+;
+;	DRIVER FUNCTION TABLE AND INSTANCE DATA
+;
+AY_FNTBL:
+	.DW	AY_RESET
+	.DW	AY_VOLUME
+	.DW	AY_PERIOD
+	.DW	AY_NOTE
+	.DW	AY_PLAY
+	.DW	AY_QUERY
+
+#IF (($ - AY_FNTBL) != (SND_FNCNT * 2))
+	.ECHO	"*** INVALID SND FUNCTION TABLE ***\n"
+	!!!!!
+#ENDIF
+;
+AY_IDAT	.EQU	0			; NO INSTANCE DATA ASSOCIATED WITH THIS DEVICE
+;
+;======================================================================
+;
+;	DEVICE CAPABILITIES AND CONFIGURATION
+;
+SBCV2004	.EQU	1		; USE SBC-V2-004 HALF CLOCK DIVIDER	
+;
+AY_TONECNT	.EQU	3		; COUNT NUMBER OF TONE CHANNELS
+AY_NOISECNT	.EQU	1		; COUNT NUMBER OF NOISE CHANNELS
+;
+AY_PHICLK	.EQU	3579500
+AY_CLKDIV	.EQU	2
+AY_CLK		.EQU	AY_PHICLK / AY_CLKDIV
+;
+#INCLUDE "audio.inc"
+;
+;======================================================================
+;
+;	DRIVER INITIALIZATION (THERE IS NO PRE-INITIALIZATION)
+;
+;	ANNOUNCE DEVICE ON CONSOLE. ACTIVATE DEVICE IF REQUIRED.
+;	SETUP FUNCTION TABLES. SETUP THE DEVICE.
+;	ANNOUNCE DEVICE WITH BEEP. SET VOLUME OFF.
+;	RETURN INITIALIZATION STATUS
+;
+AY38910_INIT:
+	CALL	NEWLINE			; ANNOUNCE
+	PRTS("AY: IO=0x$")
+	LD	A,AY_RSEL
+	CALL	PRTHEXBYTE
+;
+#IF ((AYMODE == AYMODE_SCG) | (AYMODE == AYMODE_N8))
+					; ACTIVATE DEVICE
+	LD	A,$FF			; BIT 4 IS AY RESET CONTROL, BIT 3 IS ACTIVE LED
+	OUT	(AY_ACR),A		; SET INIT AUX CONTROL REG
+#ENDIF
+;
+	LD	IY, AY_IDAT		; SETUP FUNCTION TABLE
+	LD	BC, AY_FNTBL		; POINTER TO INSTANCE DATA
+	LD	DE, AY_IDAT		; BC := FUNCTION TABLE ADDRESS
+	CALL	SND_ADDENT		; DE := INSTANCE DATA PTR
+;
+	CALL	AY_INIT			; SET DEFAULT CHIP CONFIGURATION
+;
+	LD	E,$07			; SET VOLUME TO 50%
+	CALL	AY_SETV			; ON ALL CHANNELS
+;
+	LD	D,AY_R2CHBP		; BEEP ON CHANNEL B (CENTER)
+	LD	E,$55
+	CALL	AY_WRTPSG		; R02 = $55 = 01010101
+	LD	D,AY_R3CHBP
+	LD	E,$00
+	CALL	AY_WRTPSG		; R03 = $00 = XXXX0000
+;  
+	CALL	LDELAY			; HALF SECOND 
+;
+	LD	E,$00			; SET VOLUME OFF
+	CALL	AY_SETV			; ON ALL CHANNELS	
+;
+;	RET
+;
+;======================================================================
+;	INITIALIZE DEVICE
+;======================================================================
+;
+AY_INIT:
+	LD	D,AY_R7ENAB		; SET MIXER CONTROL / IO ENABLE
+	LD	E,$F8			; $F8 - 11 111 000
+	CALL	AY_WRTPSG		; I/O PORTS = OUTPUT, NOISE CHANNEL C, B, A DISABLE, TONE CHANNEL C, B, A ENABLE
+	RET
+;
+;======================================================================
+;	SET VOLUME ALL CHANNELS
+;======================================================================
+;
+AY_SETV:
+	LD	B,AY_TONECNT		; NUMBER OF CHANNELS		
+	LD	D,AY_R8AVOL		; BASE REGISTER FOR VOLUME
+AY_SV:	CALL	AY_WRTPSG		; CYCLING THROUGH ALL CHANNELS
+	INC	D
+	DJNZ	AY_SV
+	RET
+;
+;======================================================================
+;	SOUND DRIVER FUNCTION - RESET
+;
+;	INITIALIZE DEVICE. SET VOLUME OFF. RESET VOLUME AND TONE VARIABLES.
+;
+;======================================================================
+;
+AY_RESET:
+	AUDTRACE(TRACE_INIT)
+;
+	CALL	AY_INIT			; SET DEFAULT CHIP CONFIGURATION
+;
+	AUDTRACE(TRACE_VOLUME_OFF)
+	LD	E,0			; SET VOLUME OFF
+	CALL	AY_SETV			; ON ALL CHANNELS
+;
+	XOR	A			; SIGNAL SUCCESS
+	LD	(PENDING_VOLUME),A	; SET VOLUME TO ZERO
+	LD	H,A
+	LD	L,A
+	LD	(PENDING_PERIOD),HL	; SET TONE PERIOD TO ZERO
+;	
+	RET
+;
+;======================================================================
+;	SOUND DRIVER FUNCTION - VOLUME
+;======================================================================
+;
+AY_VOLUME:
+	AUDDEBUG("AY3VOL ")
+	AUDTRACE_L
+	AUDDEBUG("\r\n")
+	LD	A,L			; SAVE VOLUME
+	LD	(PENDING_VOLUME), A
+;
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+;======================================================================
+;	SOUND DRIVER FUNCTION - PERIOD
+;======================================================================
+;
+AY_PERIOD:
+	AUDDEBUG("AY3PRD ")
+	AUDTRACE_HL
+	AUDDEBUG("\r\n")
+
+	LD	A, H			; MAXIMUM TONE PERIOD IS 12-BITS
+	CP	$10			; ALLOWED RANGE IS 0001-0FFF (4095)
+	JP	NC, AY_QUERY_PERIOD1	; RETURN NZ IF NUMBER TOO LARGE
+
+	LD	(PENDING_PERIOD), HL	; SAVE AND 
+	XOR	A			; SIGNAL SUCCESS
+	RET
+
+AY_QUERY_PERIOD1:
+	LD	L, $FF
+	LD	H, L			; REQUESTED PERIOD IS LARGER 
+	LD	(PENDING_PERIOD), HL	; THAN THE DEVICE CAN SUPPORT
+	OR	L			; SO SIGNAL FAILURE
+	RET
+;
+;======================================================================
+;	SOUND DRIVER FUNCTION - NOTE
+;======================================================================
+;
+AY_NOTE:
+	AUDDEBUG("AY3NOT ")
+	AUDTRACE_L
+	AUDDEBUG("\r\n")
+
+	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	E, L			; HL = AY3NOTETBL + HL
+	LD	D, H
+	LD	HL, AY3NOTETBL
+	ADD	HL, DE
+
+	LD	A, (HL)			; RETRIEVE PERIOD COUNT FROM AY3NOTETBL
+	INC	HL
+	LD	H, (HL)
+	LD	L, A
+
+	JR	AY_PERIOD		; APPLY NOTE PERIOD
+
+AY_NOTE1:
+	OR	$FF			; NOT IMPLEMENTED YET
+	RET
+;
+;======================================================================
+;	SOUND DRIVER FUNCTION - PLAY
+;======================================================================
+;
+AY_PLAY:
+	AUDDEBUG("AY3PLY ")
+	AUDTRACE_D
+	AUDDEBUG("\r\n")
+;
+	LD	A, (PENDING_PERIOD + 1)	; CHECK THE HIGH BYTE OF THE PERIOD
+	CP	$FF
+	JR	Z, AY_PLAY1		; PERIOD IS TOO LARGE, UNABLE TO PLAY
+	CALL	AY_APPLY_VOL
+	CALL	AY_APPLY_PRD
+;
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+AY_PLAY1:				; TURN CHANNEL VOL TO OFF AND STOP PLAYING
+	LD	A, (PENDING_VOLUME)
+	PUSH	AF
+	XOR	A
+	LD	(PENDING_VOLUME), A
+	CALL	AY_APPLY_VOL
+	POP	AF
+	LD	(PENDING_VOLUME), A
+;
+	OR	$FF			; SIGNAL FAILURE
+	RET
+;
+;======================================================================
+;	SOUND DRIVER FUNCTION - QUERY AND SUBFUNCTIONS
+;======================================================================
+;
+AY_QUERY:
+	LD	A, E
+	CP	BF_SNDQ_CHCNT		; SUB FUNCTION 01
+	JR	Z, AY_QUERY_CHCNT
+;
+	CP	BF_SNDQ_VOLUME		; SUB FUNCTION 02
+	JR	Z, AY_QUERY_VOLUME
+;
+	CP	BF_SNDQ_PERIOD		; SUB FUNCTION 03
+	JR	Z, AY_QUERY_PERIOD
+;
+	CP	BF_SNDQ_DEV		; SUB FUNCTION 04
+	JR	Z, AY_QUERY_DEV
+;
+	OR	$FF			; SIGNAL FAILURE
+	RET
+;
+AY_QUERY_CHCNT:
+	LD	B, AY_TONECNT		; RETURN NUMBER OF
+	LD	C, AY_NOISECNT		; TONE AND NOISE 
+	XOR	A			; CHANNELS IN BC
+	RET
+;
+AY_QUERY_PERIOD:
+	LD	HL, (PENDING_PERIOD)	; RETURN 16-BIT PERIOD
+	XOR	A			; IN HL REGISTER
+	RET
+;
+AY_QUERY_VOLUME:
+	LD	A, (PENDING_VOLUME)	; RETURN 8-BIT VOLUME
+	LD	L, A			; IN L REGISTER
+	XOR	A
+	LD	H, A
+	RET
+;
+AY_QUERY_DEV:
+	LD	B, BF_SND_AY38910		; RETURN DEVICE IDENTIFIER
+	LD	DE, (AY_RSEL*256)+AY_RDAT	; AND ADDRESS AND DATA PORT
+	XOR	A
+	RET
+;
+;======================================================================
+;	APPLY VOLUME TO CHANNEL IN D REGISTER
+;======================================================================
+;
+AY_APPLY_VOL:
+	PUSH	DE
+	PUSH	BC
+	PUSH	AF
+;
+	LD	A,D			; LIMIT CHANNEL 0-2
+	AND	$3			; AND INDEX TO THE
+	ADD	A,AY_R8AVOL		; CHANNEL VOLUME
+	LD	D,A			; REGISTER
+;
+	AUDTRACE(TRACE_REG_WR)
+	AUDTRACE_A
+	AUDTRACE(TRACE_NEWLINE)
+;
+	LD	A, (PENDING_VOLUME)	; MAP THE VOLUME
+	RRCA				; FROM 00-FF
+	RRCA				; TO 00-0F
+	RRCA
+	RRCA
+	AND	$0F
+	LD	E,A
+;
+	CALL	AY_WRTPSG		; SET VOL (E) IN CHANNEL REG (D)
+;
+	POP	AF
+	POP	BC
+	POP	DE
+	RET
+;
+;======================================================================
+;	APPLY PERIOD TO CHANNEL IN D REGISTER
+;======================================================================
+;
+AY_APPLY_PRD:
+	PUSH	DE
+	PUSH	BC
+	PUSH	AF
+;
+	LD	A,D			; LIMIT CHANNEL 0-2
+	AND	$3			; AND INDEX TO THE
+	ADD	A,A			; CHANNEL REGISTER
+	LD	D,A			; FOR THE TONE PERIOD
+;
+	AUDTRACE(TRACE_REG_WR)
+	AUDTRACE_A
+	AUDTRACE(TRACE_NEWLINE)
+;
+	LD	HL,(PENDING_PERIOD)	; WRITE THE LOWER
+	LD	E,L			; 8-BITS OF THE TONE PERIOD
+	CALL	AY_WRTPSG
+	INC	D
+	LD	E,H			; WRITE THE UPPER
+	CALL	AY_WRTPSG       	; 8-BITS OF THE TONE PERIOD
+;
+	POP	AF
+	POP	BC
+	POP	DE
+	RET
+;
+;======================================================================
+;	
+; 	WRITE DATA IN E REGISTER TO DEVICE REGISTER D
+;	INTERRUPTS DISABLE DURING WRITE. WRITE IN SLOW MODE IF Z180 CPU.
+; 
+;======================================================================
+;
+AY_WRTPSG:
+	HB_DI
+#IF (SBCV2004)
+	LD	A,8			; SBC-V2-004 CHANGE
+	OUT	(112),A			; TO HALF CLOCK SPEED
+#ENDIF
+#IF (CPUFAM == CPU_Z180)
+	IN0	A,(Z180_DCNTL)		; GET WAIT STATES
+	PUSH	AF			; SAVE VALUE
+	OR	%00110000		; FORCE SLOW OPERATION (I/O W/S=3)
+	OUT0	(Z180_DCNTL),A		; AND UPDATE DCNTL
+#ENDIF
+	LD	A,D			; SELECT THE REGISTER WE 
+	OUT	(AY_RSEL),A		; WANT TO WRITE TO
+	LD	A,E			; WRITE THE VALUE TO
+	OUT	(AY_RDAT),A		; THE SELECTED REGISTER
+#IF (CPUFAM == CPU_Z180)
+	POP	AF			; GET SAVED DCNTL VALUE
+	OUT0	(Z180_DCNTL),A		; AND RESTORE IT
+#ENDIF
+#IF (SBCV2004)
+	LD	A,0			; SBC-V2-004 CHANGE TO
+	OUT	(112),A			; NORMAL CLOCK SPEED
+#ENDIF
+	HB_EI
+	RET
+;
+;======================================================================
+;
+PENDING_PERIOD		.DW	0	; PENDING PERIOD (12 BITS)
+PENDING_VOLUME		.DB	0	; PENDING VOL (8 BITS)
+
+#IF AUDIOTRACE
+TRACE_INIT		.DB	"\r\nAY_INIT CALLED\r\n$"
+TRACE_VOLUME_OFF	.DB	"\r\nAY_VOLUME_OFF\r\n$"
+TRACE_VOLUME_SET	.DB	"\r\nAY_VOLUME_SET CH: $"
+TRACE_PLAY		.DB	"\r\nPLAY\r\n$"
+TRACE_VOLUME		.DB	", VOL: $"
+TRACE_REG_WR		.DB	"\r\nOUT AY-3-8910 $"
+TRACE_PERIOD_SET	.DB	"\r\nAY_PERIOD_SET CH: $"
+TRACE_PERIOD		.DB	", PERIOD: $"
+TRACE_NEWLINE		.DB	"\r\n$"
+#ENDIF
+;
+; THE FREQUENCY BY QUARTER TONE STARTING AT A1#
+;
+;======================================================================
+;	FREQUENCY TONE TABLE
+;======================================================================
+;
+;		PERIOD	OCTAVE	NOTE	MIDI#
+;
+AY3NOTETBL:
+;	.DW	6842	;0		12
+;	.DW	6458	;0		13
+;	.DW	6096	;0		14
+;	.DW	5751	;0		15
+;	.DW	5430	;0		16
+;	.DW	5124	;0		17
+;	.DW	4838	;0		18
+;	.DW	4566	;0		19
+;	.DW	4309	;0		20
+	.DW	4068	;0	A0	21
+	.DW	3839	;0		22
+	.DW	3624	;0		23
+	.DW	3421	;1		24
+	.DW	3228 	;1		25
+	.DW	3047 	;1		26
+	.DW	2876 	;1		27
+	.DW	2715 	;1		28
+	.DW	2563 	;1		29
+	.DW	2419 	;1		30
+	.DW	2283 	;1		31
+	.DW	2155 	;1		32
+	.DW	2034 	;1		33
+	.DW	1920 	;1		34
+	.DW	1812	;1		35
+	.DW	1710	;2		36
+	.DW	1614 	;2		37
+	.DW	1524 	;2		38
+	.DW	1438 	;2		39
+	.DW	1357 	;2		40
+	.DW	1281 	;2		41
+	.DW	1209 	;2		42
+	.DW	1141 	;2		43
+	.DW	1077 	;2		44
+	.DW	1017 	;2		45
+	.DW	960  	;2		46
+	.DW	906	;2		47
+	.DW	855	;3		48
+	.DW	807 	;3		49
+	.DW	762 	;3		50
+	.DW	719 	;3		51
+	.DW	679 	;3		52
+	.DW	641 	;3		53
+	.DW	605 	;3		54
+	.DW	571 	;3		55
+	.DW	539 	;3		56
+	.DW	508 	;3		57
+	.DW	480 	;3		58
+	.DW	453	;3		59
+	.DW	428	;4		60
+	.DW	404 	;4		61
+	.DW	381 	;4		62
+	.DW	360 	;4		63
+	.DW	339 	;4		64
+	.DW	320 	;4		65
+	.DW	302 	;4		66
+	.DW	285 	;4		67
+	.DW	269 	;4		68
+	.DW	254 	;4		69
+	.DW	240 	;4		70
+	.DW	226	;4		71
+	.DW	214	;5		72
+	.DW	202 	;5		73
+	.DW	190 	;5		74
+	.DW	180 	;5		75
+	.DW	170 	;5		76
+	.DW	160 	;5		77
+	.DW	151 	;5		78
+	.DW	143 	;5		79
+	.DW	135 	;5		80
+	.DW	127 	;5		81
+	.DW	120 	;5		82
+	.DW	113	;5		83
+	.DW	107	;6		84
+	.DW	101 	;6		85
+	.DW	95  	;6		86
+	.DW	90  	;6		87
+	.DW	85  	;6		88
+	.DW	80  	;6		89
+	.DW	76  	;6		90
+	.DW	71  	;6		91
+	.DW	67  	;6		92
+	.DW	64  	;6		93
+	.DW	60  	;6		94
+	.DW	57	;6		95
+	.DW	53	;7		96
+	.DW	50 	;7		97
+	.DW	48 	;7		98
+	.DW	45 	;7		99
+	.DW	42 	;7		100
+	.DW	40 	;7		101
+	.DW	38 	;7		102
+	.DW	36 	;7		103
+	.DW	34 	;7		104
+	.DW	32 	;7		105
+	.DW	30 	;7		106
+	.DW	28	;7		107
+	.DW	27	;8		108
+	.DW	25 	;8		109
+	.DW	24 	;8		110
+	.DW	22 	;8		111
+	.DW	21 	;8		112
+	.DW	20 	;8		113
+	.DW	19 	;8		114
+	.DW	18 	;8		115
+	.DW	17 	;8		116
+	.DW	16 	;8		117
+	.DW	15 	;8		118
+	.DW	14	;8		119
+	.DW	13	;9		120
+	.DW	13	;9		121
+	.DW	12	;9		122
+	.DW	11	;9		123
+	.DW	11	;9		124
+	.DW	10	;9		125
+	.DW	9 	;9		126
+	.DW	9 	;9		127
+	.DW	8 	;9		128
+
+SIZ_AY3NOTETBL	.EQU	$ - AY3NOTETBL
+		.ECHO	"AY-3-8910 approx "
+		.ECHO	SIZ_AY3NOTETBL / 2 / 12
+		.ECHO	" Octaves.  Last note index supported: "
+
+		.ECHO SIZ_AY3NOTETBL / 2
+		.ECHO "\n"
diff --git a/Source/HBIOS/cfg_dyno.asm b/Source/HBIOS/cfg_dyno.asm
index 6f85b242..23f330c7 100644
--- a/Source/HBIOS/cfg_dyno.asm
+++ b/Source/HBIOS/cfg_dyno.asm
@@ -158,4 +158,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_ezz80.asm b/Source/HBIOS/cfg_ezz80.asm
index a6646994..189fa5f6 100644
--- a/Source/HBIOS/cfg_ezz80.asm
+++ b/Source/HBIOS/cfg_ezz80.asm
@@ -183,4 +183,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_master.asm b/Source/HBIOS/cfg_master.asm
index 7c3f00ab..c8255606 100644
--- a/Source/HBIOS/cfg_master.asm
+++ b/Source/HBIOS/cfg_master.asm
@@ -238,4 +238,5 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 UFBASE		.EQU	$0C		; UF: REGISTERS BASE ADR
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index e869de18..da75f165 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -192,4 +192,5 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 UFBASE		.EQU	$0C		; UF: REGISTERS BASE ADR
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index 9e016cf8..d32b7edf 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -192,4 +192,5 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 FIFO_BASE	.EQU	$0C		; UF: REGISTERS BASE ADR
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_rcz180.asm b/Source/HBIOS/cfg_rcz180.asm
index 2f04e152..bd6e086c 100644
--- a/Source/HBIOS/cfg_rcz180.asm
+++ b/Source/HBIOS/cfg_rcz180.asm
@@ -192,4 +192,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_rcz80.asm b/Source/HBIOS/cfg_rcz80.asm
index 61de3c2e..b2b072d0 100644
--- a/Source/HBIOS/cfg_rcz80.asm
+++ b/Source/HBIOS/cfg_rcz80.asm
@@ -198,4 +198,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_sbc.asm b/Source/HBIOS/cfg_sbc.asm
index 329944b4..f5da3829 100644
--- a/Source/HBIOS/cfg_sbc.asm
+++ b/Source/HBIOS/cfg_sbc.asm
@@ -194,4 +194,5 @@ UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 UFBASE		.EQU	$0C		; UF: REGISTERS BASE ADR
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_scz180.asm b/Source/HBIOS/cfg_scz180.asm
index 955790e7..9183f448 100644
--- a/Source/HBIOS/cfg_scz180.asm
+++ b/Source/HBIOS/cfg_scz180.asm
@@ -187,4 +187,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_zeta.asm b/Source/HBIOS/cfg_zeta.asm
index 979d4975..a8b9eea6 100644
--- a/Source/HBIOS/cfg_zeta.asm
+++ b/Source/HBIOS/cfg_zeta.asm
@@ -138,4 +138,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/cfg_zeta2.asm b/Source/HBIOS/cfg_zeta2.asm
index 31b97c7f..d76fcef6 100644
--- a/Source/HBIOS/cfg_zeta2.asm
+++ b/Source/HBIOS/cfg_zeta2.asm
@@ -148,4 +148,5 @@ PPI_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
 UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
 
 SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY-3-8910 SOUND DRIVER
 AUDIOTRACE	.EQU	FALSE		; ENABLE TRACING TO CONSOLE OF SOUND DRIVER
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index 708b57ef..3e058bd1 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -1677,6 +1677,9 @@ HB_INITTBL:
 #IF (SN76489ENABLE)
 	.DW	SN76489_INIT
 #ENDIF
+#IF (AY38910ENABLE)
+	.DW	AY38910_INIT
+#ENDIF
 #IF (ASCIENABLE)
 	.DW	ASCI_INIT
 #ENDIF
@@ -3352,6 +3355,14 @@ SIZ_SN76489	.EQU	$ - ORG_SN76489
 		.ECHO	SIZ_SN76489
 		.ECHO	" bytes.\n"
 #ENDIF
+#IF (AY38910ENABLE)
+ORG_AY38910	.EQU	$
+  #INCLUDE "ay38910.asm"
+SIZ_AY38910	.EQU	$ - ORG_AY38910
+		.ECHO	"AY38910 occupies "
+		.ECHO	SIZ_AY38910
+		.ECHO	" bytes.\n"
+#ENDIF
 ;
 #DEFINE USEDELAY
 #INCLUDE "util.asm"
diff --git a/Source/HBIOS/hbios.inc b/Source/HBIOS/hbios.inc
index a0f22099..a07e8a27 100644
--- a/Source/HBIOS/hbios.inc
+++ b/Source/HBIOS/hbios.inc
@@ -72,7 +72,7 @@ BF_SNDQ_DEV		.EQU	BF_SNDQ_STATUS + 4	; RETURN DEVICE TYPE CODE AND IO PORTS - TY
 
 BF_SNDDEV		.EQU	0			; TYPES OF SOUND DRIVERS
 BF_SND_SN76489		.EQU	BF_SNDDEV + 1
-BF_SND_SNAY38910	.EQU	BF_SNDDEV + 2
+BF_SND_AY38910		.EQU	BF_SNDDEV + 2
 
 ;
 BF_SYS		.EQU	$F0
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index 4ce9546b..5d849893 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -347,7 +347,7 @@ SN7_FNTBL:
 PENDING_PERIOD
 	.DW	0		; PENDING PERIOD (10 BITS)
 PENDING_VOLUME
-	.DB	0		; PENDING VOL (8 BITS -> DOWNOVERTED TO 4 BITS AND INVERTED)
+	.DB	0		; PENDING VOL (8 BITS -> DOWNCONVERTED TO 4 BITS AND INVERTED)
 
 STR_MESSAGELT	.DB	"\r\nSN76489: LEFT IO=0x$"
 STR_MESSAGERT	.DB	", RIGHT IO=0x$"
@@ -364,7 +364,7 @@ TRACE_PERIOD		.DB	", PERIOD: $"
 TRACE_NEWLINE		.DB	"\r\n$"
 #ENDIF
 
-; THE FREQUENCY BY QUATER TONE STARTING AT A1#
+; THE FREQUENCY BY QUARTER TONE STARTING AT A1#
 SN7NOTETBL:
 	.DW	A1S
 	.DW	SN7RATIO / 5912