From 7a209d4053b6684b404880645a2abf2a052e8390 Mon Sep 17 00:00:00 2001
From: Wayne Warthen <wwarthen@gmail.com>
Date: Sat, 8 Jul 2023 18:03:13 -0700
Subject: [PATCH] S100 Monitor Update

The S100 Monitor will now allow launching RomWBW using the 'B' command.
---
 Source/HBIOS/Makefile    | 12 +++++++++---
 Source/HBIOS/hbios.asm   | 22 ++++++++++++++++++----
 Source/HBIOS/s100mon.z80 | 14 +++++++++++++-
 Source/ver.inc           |  2 +-
 Source/ver.lib           |  2 +-
 5 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/Source/HBIOS/Makefile b/Source/HBIOS/Makefile
index 7c0607af..fbb67d93 100644
--- a/Source/HBIOS/Makefile
+++ b/Source/HBIOS/Makefile
@@ -43,6 +43,10 @@ else
 	BIOS=wbw
 endif
 
+ifeq ($(ROM_PLATFORM),S100)
+	ROMDEPS += s100mon.bin
+endif
+
 ROMNAME=${ROM_PLATFORM}_${ROM_CONFIG}
 
 # $(info DEPS=$(DEPS))
@@ -59,9 +63,7 @@ $(OBJECTS) : $(ROMDEPS)
 	if [ $(ROM_PLATFORM) != UNA ] ; then \
 		cat camel80.bin nascom.bin tastybasic.bin game.bin eastaegg.bin netboot.mod updater.bin usrrom.bin >osimg1.bin ; \
 		if [ $(ROM_PLATFORM) = S100 ] ; then \
-			$(ZXCC) $(CPM)/SLR180 -s100mon/fh ; \
-			$(ZXCC) $(CPM)/MLOAD25 -s100mon ; \
-			cat s100mon.com >osimg2.bin ; \
+			cat s100mon.bin >osimg2.bin ; \
 		else \
 			cat imgpad2.bin >osimg2.bin ; \
 		fi ; \
@@ -95,6 +97,10 @@ font%.asm:
 camel80.bin:
 	cp ../Forth/$@ .
 
+s100mon.bin:
+	$(ZXCC) $(CPM)/SLR180 -s100mon/FH
+	$(ZXCC) $(CPM)/MLOAD25 -s100mon.bin=s100mon
+
 tastybasic.bin:
 	cp ../TastyBasic/src/$@ .
 	
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index b0f1a8d1..7056487f 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -1374,19 +1374,33 @@ Z280_INITZ:
 #ENDIF
 ;
 ; S100 ROM CONTAINS A HARDWARE LEVEL MONITOR IN BANK ID 3 OF ROM.
-; IF PORT $65 BIT 1 IS SET (SET IS ZERO), THEN WE IMMEDIATELY
-; TRANSITION TO THIS MONITOR.
+; IF PORT $75 BIT 1 IS SET (SET IS ZERO), THEN WE IMMEDIATELY
+; TRANSITION TO THIS MONITOR.  PRIOR TO THE TRANSITION, WE ALSO
+; CHECK THE VALUE IN THE Z180 RELOAD REGISTER LOW.  IF IT IS ASCII 'W',
+; THEN IT MEANS THE S100 MONITOR IS ATTEMPTING TO REBOOT INTO ROMWBW
+; HBIOS.
 ;
 #IF ((PLATFORM == PLT_S100) & TRUE)
-	IN	A,($65)			; READ SWITCHES
+	; CHECK S100 BOARD DIP SWITCH, BIT 1
+	IN	A,($75)			; READ SWITCHES
 	BIT	1,A			; CHECK BIT 1
-	JR	NZ,S100MON_SKIP		; IF NOT SET, BYPASS
+	JR	NZ,S100MON_SKIP		; IF NOT SET, CONT ROMWBW BOOT
+;
+	; CHECK RELOAD REGISTER LOW FOR SPECIAL VALUE
+	IN0	A,(Z180_RLDR1L)		; GET RELOAD REG 1 LOW
+	CP	'W'			; CHECK FOR SPECIAL VALUE
+	JR	Z,S100MON_SKIP		; IF SO, DO ROMWBW BOOT
+;
+	; LAUNCH S100 MONITOR FROM ROM BANK 3
 	LD	A,BID_IMG2		; S100 MONITOR BANK
 	LD	IX,0			; EXECUTION RESUMES HERE
 	CALL	HBX_BNKCALL		; CONTINUE IN RAM BANK, DO NOT RETURN
 	HALT				; WE SHOULD NOT COME BACK HERE!
 ;
 S100MON_SKIP:
+	; RESTORE DEFAULT RELOAD REGISTER VALUE (PROBABLY NOT NEEDED)
+	XOR	A
+	OUT0	(Z180_RLDR1L),A
 #ENDIF
 ;
 ; SAVE CURRENT BANKID
diff --git a/Source/HBIOS/s100mon.z80 b/Source/HBIOS/s100mon.z80
index 1be975ae..33244f2e 100644
--- a/Source/HBIOS/s100mon.z80
+++ b/Source/HBIOS/s100mon.z80
@@ -508,7 +508,7 @@ BEGIN0:	JP	BEGIN			;JUMP OVER COMMAND TABLE
 
 TBL:	DW  FLUSH			;"@"  SEND FF to LaserJet printer
 	DW  MEMMAP			;"A"  DISPLAY A MAP OF MEMORY
-	DW  NOT_DONE			;	"B"  SWITCH CONTROL TO 68000 CPU 
+	DW  BOOT			;	"B"  SWITCH CONTROL TO 68000 CPU 
 	DW  NOT_DONE			;	"C"  BOOT IN CP/M FROM 8" DISK WITH WITH ZFDC FDC 
 	DW  DISP			;"D"  DISPLAY MEMORY (IN HEX & ASCII)
 	DW  CHAR_TEST			;"E"  ECHO CHAR IN TO CHAR OUT
@@ -848,6 +848,18 @@ OTA:	PUSH	BC
 	RET
 
 
+;---------------------------- B COMMAND    BOOT ROMWBW -------------------------------------------
+
+;RESTART SYSTEM WITH ROMWBW BOOT OVERRIDE FLAG IN THE Z180 RELOAD
+;REGISTER 1 LOW
+
+BOOT:
+	LD	A,'W'			;OVERRIDE VALUE
+	OUT0	(Z180_RLDR1L),A		;SET RELOAD REGISTER 1 LOW
+	XOR	A			;ROM BANK 0 PLEASE
+	CALL	bnksel			;SELECT BANK IN LOW MEM
+	JP	0			;AND JUMP TO THE START
+
 ;----------------------- D COMMAND    DISPLAY MEMORY IN HEX ---------------------------------------
 
 DISP:	CALL	EXLF			;GET PARAMETERS IN [HL],[DE]
diff --git a/Source/ver.inc b/Source/ver.inc
index e7d57dd2..291ac72f 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,7 +2,7 @@
 #DEFINE	RMN	3
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.3.0-dev.30"
+#DEFINE BIOSVER	"3.3.0-dev.31"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
diff --git a/Source/ver.lib b/Source/ver.lib
index 4e0bc87d..3c3b4fe5 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	3
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.3.0-dev.30"
+	db	"3.3.0-dev.31"
 	endm