ay38910 updates

cleanups, optimizations, protect registers

Source/HBIOS/ay38910.asm

@@ -58,7 +58,7 @@ 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
+SBCV2004	.EQU	0		; 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
@@ -107,7 +107,7 @@ AY38910_INIT:
 	LD	E,$00
 	CALL	AY_WRTPSG		; R03 = $00 = XXXX0000
 ;
-	CALL	LDELAY			; HALF SECOND
+	CALL	LDELAY			; HALF SECOND DELAY
 ;
 	LD	E,$00			; SET VOLUME OFF
 	CALL	AY_SETV			; ON ALL CHANNELS
@@ -146,6 +146,8 @@ AY_SV:	CALL	AY_WRTPSG		; CYCLING THROUGH ALL CHANNELS
 AY_RESET:
 	AUDTRACE(AYT_INIT)
 ;
+	PUSH	DE
+	PUSH	HL
 	CALL	AY_INIT			; SET DEFAULT CHIP CONFIGURATION
 ;
 	AUDTRACE(AYT_VOLOFF)
@@ -158,6 +160,8 @@ AY_RESET:
 	LD	L,A
 	LD	(AY_PENDING_PERIOD),HL	; SET TONE PERIOD TO ZERO
 ;
+	POP	HL
+	POP	DE
 	RET
 ;
 ;======================================================================
@@ -182,22 +186,19 @@ AY_PERIOD:
 	AUDTRACE(AYT_PERIOD)
 	AUDTRACE_HL
 	AUDTRACE_CR
-
+;
 	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	(AY_PENDING_PERIOD), HL	; SAVE AND
-	XOR	A			; SIGNAL SUCCESS
-	RET
-
-AY_QUERY_PERIOD1:
-	LD	L, $FF
-	LD	H, L			; REQUESTED PERIOD IS LARGER
-	LD	(AY_PENDING_PERIOD), HL	; THAN THE DEVICE CAN SUPPORT
-	OR	L			; SO SIGNAL FAILURE
+	AND	11110000B		; ALLOWED RANGE IS 0001-0FFF (4095)
+	JR	NZ, AY_PERIOD1		; RETURN NZ IF NUMBER TOO LARGE
+	LD	(AY_PENDING_PERIOD), HL	; SAVE AND RETURN SUCCESSFUL
 	RET
 ;
+AY_PERIOD1:
+	LD	A, $FF			; REQUESTED PERIOD IS LARGER
+	LD	(AY_PENDING_PERIOD), A	; THAN THE DEVICE CAN SUPPORT
+	LD	(AY_PENDING_PERIOD+1), A; SO SET PERIOD TO FFFF
+	RET				; AND RETURN FAILURE
+;
 ;======================================================================
 ;	SOUND DRIVER FUNCTION - NOTE
 ;======================================================================
@@ -206,33 +207,44 @@ 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
+;					; 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
+	EX	DE,HL
+	LD	HL, AY3NOTETBL		; HL = AY3NOTETBL + HL
 	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
-
+;
+	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
+;	D = CHANNEL
+;	A = EXIT STATUS
 ;======================================================================
 ;
 AY_PLAY:
@@ -241,23 +253,63 @@ AY_PLAY:
 	AUDTRACE_CR
 ;
 	LD	A, (AY_PENDING_PERIOD + 1)	; CHECK THE HIGH BYTE OF THE PERIOD
-	CP	$FF
+	INC	A
 	JR	Z, AY_PLAY1		; PERIOD IS TOO LARGE, UNABLE TO PLAY
-	CALL	AY_APPLY_VOL
-	CALL	AY_APPLY_PRD
+;
+	PUSH	HL			
+	PUSH	DE
+	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(AYT_REGWR)
+	AUDTRACE_A
+	AUDTRACE_CR
+;
+	LD	HL,AY_PENDING_PERIOD	; WRITE THE LOWER
+	ld	E,(HL)			; 8-BITS OF THE TONE PERIOD
+	CALL	AY_WRTPSG
+	INC	D			; NEXT REGISTER
+	INC	HL			; NEXT BYTE
+	LD	E,(HL)			; WRITE THE UPPER
+	CALL	AY_WRTPSG       	; 8-BITS OF THE TONE PERIOD
+;
+	POP	DE			; RECALL CHANNEL
+	PUSH	DE			; SAVE CHANNEL
+;
+	LD	A,D			; LIMIT CHANNEL 0-2
+	AND	$3			; AND INDEX TO THE
+	ADD	A,AY_R8AVOL		; CHANNEL VOLUME
+	LD	D,A			; REGISTER
+;
+	AUDTRACE(AYT_REGWR)
+	AUDTRACE_A
+	AUDTRACE_CR
+;
+	INC	HL			; NEXT BYTE
+	LD	E,(HL)
+	SRL	E			; MAP THE VOLUME
+	SRL	E			; FROM 00-FF		
+	SRL	E			; TO 00-0F
+	SRL	E
+	CALL	AY_WRTPSG		; SET VOL (E) IN CHANNEL REG (D)
+;
+	POP	DE			; RECALL CHANNEL
+	POP	HL
 ;
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
-AY_PLAY1:				; TURN CHANNEL VOL TO OFF AND STOP PLAYING
-	LD	A, (AY_PENDING_VOLUME)
-	PUSH	AF
-	XOR	A
-	LD	(AY_PENDING_VOLUME), A
-	CALL	AY_APPLY_VOL
-	POP	AF
-	LD	(AY_PENDING_VOLUME), A
-;
+AY_PLAY1:
+	PUSH	DE			; TURN VOLUME OFF TO STOP PLAYING
+	LD	A,D			; LIMIT CHANNEL 0-2
+	AND	$3			; AND INDEX TO THE
+	ADD	A,AY_R8AVOL		; CHANNEL VOLUME
+	LD	D,A			; REGISTER
+	LD	E,0
+	CALL	AY_WRTPSG		; SET VOL (E) IN CHANNEL REG (D)
+	POP	DE
 	OR	$FF			; SIGNAL FAILURE
 	RET
 ;
@@ -307,70 +359,6 @@ AY_QUERY_DEV:
 	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(AYT_REGWR)
-	AUDTRACE_A
-	AUDTRACE_CR
-;
-	LD	A, (AY_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	$3			; AND INDEX TO THE
-	ADD	A,A			; CHANNEL REGISTER
-	LD	D,A			; FOR THE TONE PERIOD
-;
-	AUDTRACE(AYT_REGWR)
-	AUDTRACE_A
-	AUDTRACE_CR
-
-;
-	LD	HL,(AY_PENDING_PERIOD)	; WRITE THE LOWER
-	LD	E,L			; 8-BITS OF THE TONE PERIOD
-	CALL	AY_WRTPSG
-	INC	D
-	LD	E,H			; WRITE THE UPPER
-	CALL	AY_WRTPSG       	; 8-BITS OF THE TONE PERIOD
-;
-	POP	AF
-	POP	BC
-	POP	DE
-	RET
-;
-;======================================================================
 ;
 ; 	WRITE DATA IN E REGISTER TO DEVICE REGISTER D
 ;	INTERRUPTS DISABLE DURING WRITE. WRITE IN SLOW MODE IF Z180 CPU.
@@ -406,9 +394,9 @@ AY_WRTPSG:
 ;
 ;======================================================================
 ;
-AY_PENDING_PERIOD		.DW	0	; PENDING PERIOD (12 BITS)
-AY_PENDING_VOLUME		.DB	0	; PENDING VOL (8 BITS)
-
+AY_PENDING_PERIOD	.DW	0	; PENDING PERIOD (12 BITS)	; ORDER
+AY_PENDING_VOLUME	.DB	0	; PENDING VOL (8 BITS)		; SIGNIFICANT
+;
 #IF AUDIOTRACE
 AYT_INIT		.DB	"\r\nAY_INIT\r\n$"
 AYT_VOLOFF		.DB	"\r\nAY_VOLUME OFF\r\n$"
@@ -419,10 +407,8 @@ AYT_PLAY		.DB	"\r\nAY_PLAY CH: $"
 AYT_REGWR		.DB	"\r\nOUT AY-3-8910 $"
 #ENDIF
 ;
-; THE FREQUENCY BY QUARTER TONE STARTING AT A1#
-;
 ;======================================================================
-;	FREQUENCY TONE TABLE
+;	FREQUENCY TONE TABLE (SEMITONE CURRENTLY)
 ;======================================================================
 ;
 ;		PERIOD	OCTAVE	NOTE	MIDI#