From b3f8cce0ae7aa34efaef0b36ddf2457e33ba0ed4 Mon Sep 17 00:00:00 2001
From: b1ackmai1er <difficultylevelhigh@gmail.com>
Date: Wed, 6 May 2020 20:48:35 +0800
Subject: [PATCH] Basic ay-3-8910 harware detection

---
 Source/HBIOS/ay38910.asm | 59 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 55 insertions(+), 4 deletions(-)

diff --git a/Source/HBIOS/ay38910.asm b/Source/HBIOS/ay38910.asm
index 64b6e648..e3070813 100644
--- a/Source/HBIOS/ay38910.asm
+++ b/Source/HBIOS/ay38910.asm
@@ -4,26 +4,32 @@
 ;
 ;======================================================================
 ;
+AY_RCSND	.EQU	0		; 0 = EB MODULE, 1=MF MODULE
+;
 #IF (AYMODE == AYMODE_SCG)
 AY_RSEL		.EQU	$9A
 AY_RDAT		.EQU	$9B
+AY_RIN		.EQU	AY_RSEL
 AY_ACR		.EQU	$9C
 #ENDIF
 ;
 #IF (AYMODE == AYMODE_N8)
 AY_RSEL		.EQU	$9C
 AY_RDAT		.EQU	$9D
+AY_RIN		.EQU	AY_RSEL
 AY_ACR		.EQU	N8_DEFACR
 #ENDIF
 ;
 #IF (AYMODE == AYMODE_RCZ80)	
 AY_RSEL		.EQU	$D8
 AY_RDAT		.EQU	$D0
+AY_RIN		.EQU	AY_RSEL+AY_RCSND
 #ENDIF
 ;
 #IF (AYMODE == AYMODE_RCZ180)
 AY_RSEL		.EQU	$68
 AY_RDAT		.EQU	$60
+AY_RIN		.EQU	AY_RSEL+AY_RCSND
 #ENDIF
 ;
 ;======================================================================
@@ -87,12 +93,24 @@ AY38910_INIT:
 	CALL	PRTHEXBYTE
 ;
 #IF ((AYMODE == AYMODE_SCG) | (AYMODE == AYMODE_N8))
-					; ACTIVATE DEVICE
-	LD	A,$FF			; BIT 4 IS AY RESET CONTROL, BIT 3 IS ACTIVE LED
+	LD	A,$FF			; ACTIVATE DEVICEBIT 4 IS AY RESET CONTROL, BIT 3 IS ACTIVE LED
 	OUT	(AY_ACR),A		; SET INIT AUX CONTROL REG
 #ENDIF
+
+	LD	D,AY_R2CHBP		; SIMPLE HARDWARE PROBE
+	LD	E,$AA
+	CALL	AY_WRTPSG		; WRITE AND 
+	CALL	AY_RDPSG
+	LD	A,$AA
+	CP	E
+	JR	Z,AY_FND
+
+	CALL	PRTSTRD \ .TEXT " NOT PRESENT$"
+
+	LD	A,$FF			; UNSUCCESSFULL INIT		
+	RET
 ;
-	LD	IY, AY_IDAT		; SETUP FUNCTION TABLE
+AY_FND:	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
@@ -114,7 +132,8 @@ AY38910_INIT:
 	LD	E,$00			; SET VOLUME OFF
 	CALL	AY_SETV			; ON ALL CHANNELS
 ;
-;	RET
+	XOR	A			; SUCCESSFULL INIT
+	RET
 ;
 ;======================================================================
 ;	INITIALIZE DEVICE
@@ -390,6 +409,38 @@ AY_WRTPSG:
 	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
+
+;
+;======================================================================
+;
+;	READ FROM REGISTER D AND RETURN WITH RESULT IN E
+;
+AY_RDPSG:
+	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 READ
+	IN	A,(AY_RIN)		; READ SELECTED REGISTER
+	LD	E,A
+#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