From d50593a70ee04e4f11bce44d842e22ca2fe23f7f Mon Sep 17 00:00:00 2001
From: Wayne Warthen <wwarthen@gmail.com>
Date: Mon, 1 Apr 2024 13:36:59 -0700
Subject: [PATCH] Improve TMS Reset & SN76489 Early Init

- The TMS reset function was missing a call to re-initialize the CRT registers.  This has been added.
- The SN76489 powers up in a dreadful state where it is emitting loud noise until initialized.  Added a PREINIT entry point to initialize the registers earlier.  Still not great, but a lot better.
---
 Source/HBIOS/hbios.asm   | 6 +++---
 Source/HBIOS/sn76489.asm | 6 ++++++
 Source/HBIOS/tms.asm     | 7 ++++++-
 Source/ver.inc           | 2 +-
 Source/ver.lib           | 2 +-
 5 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index 4c8acbd5..279e3110 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -1967,19 +1967,19 @@ HB_CPU1:
 	LD	(RTC_DISPACT),A		; RTC DEVICE
 	LD	(DSKY_DISPACT),A	; DSKY DEVICE
 ;
+#IF (SN76489ENABLE)
+	CALL	SN76489_PREINIT
+#ENDIF
 #IF (DSRTCENABLE)
 	CALL	DSRTC_PREINIT
 #ENDIF
-;
 #IF (DSKYENABLE)
   #IF (ICMENABLE)
 	CALL	ICM_PREINIT
   #ENDIF
-;
   #IF (PKDENABLE)
 	CALL	PKD_PREINIT
   #ENDIF
-;
   #IF (H8PENABLE)
 	CALL	H8P_PREINIT
   #ENDIF
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index cdd701e2..413b0883 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -56,6 +56,12 @@ CHANNEL_3_SILENT	.EQU	$FF
 ;
 #INCLUDE "audio.inc"
 ;
+; BLINDLY RESET THE PSG AS SOON AS WE CAN AFTER BOOT BECAUSE IT
+; DOES NOT RESET ITSELF AT POWER ON AND MAKES UGLY NOISE.
+;
+SN76489_PREINIT:
+	JR	SN7_RESET
+;
 SN76489_INIT:
 	LD	IY, SN7_IDAT		; POINTER TO INSTANCE DATA
 	LD	BC, SN7_FNTBL		; BC := FUNCTION TABLE ADDRESS
diff --git a/Source/HBIOS/tms.asm b/Source/HBIOS/tms.asm
index 63e28268..31dec655 100644
--- a/Source/HBIOS/tms.asm
+++ b/Source/HBIOS/tms.asm
@@ -350,7 +350,12 @@ TMS_VDARES:
 #IF (CPUFAM == CPU_Z180)
 	CALL	TMS_Z180IO
 #ENDIF
-TMS_VDARES1:	; ENTRY POINT TO AVOID TMS_Z180IO RECURSION
+	CALL	TMS_CRTINIT
+;
+; ENTRY POINT USED BY TMS_INIT TO AVOID DUPLICATE CALL TO TMS_CRTINIT
+; AND TMS_Z180IO.
+;
+TMS_VDARES1:
 	LD	DE,0			; ROW = 0, COL = 0
 	CALL	TMS_XY			; SEND CURSOR TO TOP LEFT
 	LD	A,' '			; BLANK THE SCREEN
diff --git a/Source/ver.inc b/Source/ver.inc
index 09fd2efb..c307fc62 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,7 +2,7 @@
 #DEFINE	RMN	5
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.5.0-dev.20"
+#DEFINE BIOSVER	"3.5.0-dev.21"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
diff --git a/Source/ver.lib b/Source/ver.lib
index bbf65959..b92a7525 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	5
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.5.0-dev.20"
+	db	"3.5.0-dev.21"
 	endm