From 10d875ffbbfd7ec2ab46c4a9d2ad7a541f7f62a4 Mon Sep 17 00:00:00 2001
From: Wayne Warthen <wwarthen@gmail.com>
Date: Wed, 20 Jan 2021 11:21:24 -0800
Subject: [PATCH] Z280 Work in Progress, SC140 Config

- Early support for native mode memory for Z280.
- Added support for SC140 as new standard build.
---
 Source/CBIOS/config.asm            |   2 +-
 Source/HBIOS/Config/RCZ280_nat.asm |  49 +++++++
 Source/HBIOS/Config/SCZ180_140.asm |  56 ++++++++
 Source/HBIOS/Makefile              |   2 +
 Source/HBIOS/dbgmon.asm            |   8 +-
 Source/HBIOS/hbios.asm             | 222 ++++++++++++++++++++++-------
 Source/HBIOS/std.asm               |   5 +-
 Source/HBIOS/z280.inc              |  10 +-
 Source/ver.inc                     |   2 +-
 Source/ver.lib                     |   2 +-
 10 files changed, 300 insertions(+), 58 deletions(-)
 create mode 100644 Source/HBIOS/Config/RCZ280_nat.asm
 create mode 100644 Source/HBIOS/Config/SCZ180_140.asm

diff --git a/Source/CBIOS/config.asm b/Source/CBIOS/config.asm
index 1ad85aee..0c2017aa 100644
--- a/Source/CBIOS/config.asm
+++ b/Source/CBIOS/config.asm
@@ -8,7 +8,7 @@ DSKTRACE	.EQU	FALSE		; ENABLE TRACING OF CBIOS DISK FUNCTION CALLS
 CPM_LOC		.EQU	$D000		; LOCATION OF START OF CCP
 ;
 #IFDEF PLTWBW
-CPM_END		.EQU	$FE00		; ROMWBW HBIOS PROXY OCCUPIES TOP 2 PAGES OF MEMORY
+CPM_END		.EQU	$FD80		; ROMWBW HBIOS PROXY OCCUPIES TOP $280 BYTES OF MEMORY
 #ENDIF
 ;
 #IFDEF PLTUNA
diff --git a/Source/HBIOS/Config/RCZ280_nat.asm b/Source/HBIOS/Config/RCZ280_nat.asm
new file mode 100644
index 00000000..5c81f316
--- /dev/null
+++ b/Source/HBIOS/Config/RCZ280_nat.asm
@@ -0,0 +1,49 @@
+;
+;==================================================================================================
+;   RC2014 Z280 STANDARD CONFIGURATION (EXTERNAL 512K RAM/ROM BANKED MEMORY MODULE)
+;==================================================================================================
+;
+; THE COMPLETE SET OF DEFAULT CONFIGURATION SETTINGS FOR THIS PLATFORM ARE FOUND IN THE
+; CFG_<PLT>.ASM INCLUDED FILE WHICH IS FOUND IN THE PARENT DIRECTORY.  THIS FILE CONTAINS
+; COMMON CONFIGURATION SETTINGS THAT OVERRIDE THE DEFAULTS.  IT IS INTENDED THAT YOU MAKE
+; YOUR CUSTOMIZATIONS IN THIS FILE AND JUST INHERIT ALL OTHER SETTINGS FROM THE DEFAULTS.
+; EVEN BETTER, YOU CAN MAKE A COPY OF THIS FILE WITH A NAME LIKE <PLT>_XXX.ASM AND SPECIFY
+; YOUR FILE IN THE BUILD PROCESS.
+;
+; THE SETTINGS BELOW ARE THE SETTINGS THAT ARE MOST COMMONLY MODIFIED FOR THIS PLATFORM.
+; MANY OF THEM ARE EQUAL TO THE SETTINGS IN THE INCLUDED FILE, SO THEY DON'T REALLY DO
+; ANYTHING AS IS.  THEY ARE LISTED HERE TO MAKE IT EASY FOR YOU TO ADJUST THE MOST COMMON
+; SETTINGS.
+;
+; N.B., SINCE THE SETTINGS BELOW ARE REDEFINING VALUES ALREADY SET IN THE INCLUDED FILE,
+; TASM INSISTS THAT YOU USE THE .SET OPERATOR AND NOT THE .EQU OPERATOR BELOW. ATTEMPTING
+; TO REDEFINE A VALUE WITH .EQU BELOW WILL CAUSE TASM ERRORS!
+;
+; PLEASE REFER TO THE CUSTOM BUILD INSTRUCTIONS (README.TXT) IN THE SOURCE DIRECTORY (TWO
+; DIRECTORIES ABOVE THIS ONE).
+;
+#define	BOOT_DEFAULT	"H"		; DEFAULT BOOT LOADER CMD ON <CR> OR AUTO BOOT
+;
+#include "cfg_rcz280.asm"
+;
+CRTACT		.SET	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+;
+CPUOSC		.SET	24000000	; CPU OSC FREQ IN MHZ
+;
+MEMMGR		.SET	MM_Z280		; MEMORY MANAGER: MM_[SBC|Z2|N8|Z180|Z280]
+;
+INTMODE		.SET	1
+;
+Z280_MEMWAIT	.SET	0		; Z280: MEMORY WAIT STATES (0-3)
+Z280_IOWAIT	.SET	1		; Z280: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
+Z280_INTWAIT	.SET	0		; Z280: INT ACK WAIT STATUS (0-3)
+;
+UARTENABLE	.SET	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+ACIAENABLE	.SET	TRUE		; ACIA: ENABLE MOTOROLA 6850 ACIA DRIVER (ACIA.ASM)
+SIOENABLE	.SET	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
+;
+IDEENABLE	.SET	TRUE		; IDE: ENABLE IDE DISK DRIVER (IDE.ASM)
+;
+PPIDEENABLE	.SET	TRUE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
+;
+PRPENABLE	.SET	FALSE		; PRP: ENABLE ECB PROPELLER IO BOARD DRIVER (PRP.ASM)
diff --git a/Source/HBIOS/Config/SCZ180_140.asm b/Source/HBIOS/Config/SCZ180_140.asm
new file mode 100644
index 00000000..2bd0b7c1
--- /dev/null
+++ b/Source/HBIOS/Config/SCZ180_140.asm
@@ -0,0 +1,56 @@
+;
+;==================================================================================================
+;   SC140 STANDARD CONFIGURATION
+;==================================================================================================
+;
+; THE COMPLETE SET OF DEFAULT CONFIGURATION SETTINGS FOR THIS PLATFORM ARE FOUND IN THE
+; CFG_<PLT>.ASM INCLUDED FILE WHICH IS FOUND IN THE PARENT DIRECTORY.  THIS FILE CONTAINS
+; COMMON CONFIGURATION SETTINGS THAT OVERRIDE THE DEFAULTS.  IT IS INTENDED THAT YOU MAKE
+; YOUR CUSTOMIZATIONS IN THIS FILE AND JUST INHERIT ALL OTHER SETTINGS FROM THE DEFAULTS.
+; EVEN BETTER, YOU CAN MAKE A COPY OF THIS FILE WITH A NAME LIKE <PLT>_XXX.ASM AND SPECIFY
+; YOUR FILE IN THE BUILD PROCESS.
+;
+; THE SETTINGS BELOW ARE THE SETTINGS THAT ARE MOST COMMONLY MODIFIED FOR THIS PLATFORM.
+; MANY OF THEM ARE EQUAL TO THE SETTINGS IN THE INCLUDED FILE, SO THEY DON'T REALLY DO
+; ANYTHING AS IS.  THEY ARE LISTED HERE TO MAKE IT EASY FOR YOU TO ADJUST THE MOST COMMON
+; SETTINGS.
+;
+; N.B., SINCE THE SETTINGS BELOW ARE REDEFINING VALUES ALREADY SET IN THE INCLUDED FILE,
+; TASM INSISTS THAT YOU USE THE .SET OPERATOR AND NOT THE .EQU OPERATOR BELOW. ATTEMPTING
+; TO REDEFINE A VALUE WITH .EQU BELOW WILL CAUSE TASM ERRORS!
+;
+; PLEASE REFER TO THE CUSTOM BUILD INSTRUCTIONS (README.TXT) IN THE SOURCE DIRECTORY (TWO
+; DIRECTORIES ABOVE THIS ONE).
+;
+#DEFINE		PLATFORM_NAME	"SC140"
+;
+#include "cfg_scz180.asm"
+;
+CPUOSC		.SET	18432000	; CPU OSC FREQ IN MHZ
+;
+Z180_CLKDIV	.SET	1		; Z180: CHK DIV: 0=OSC/2, 1=OSC, 2=OSC*2
+Z180_MEMWAIT	.SET	0		; Z180: MEMORY WAIT STATES (0-3)
+Z180_IOWAIT	.SET	1		; Z180: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
+;
+HBIOS_MUTEX	.SET	FALSE		; ENABLE REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
+;
+LEDENABLE	.SET	TRUE		; ENABLE STATUS LED (SINGLE LED)
+;
+DIAGENABLE	.SET	TRUE		; ENABLES OUTPUT TO 8 BIT LED DIAGNOSTIC PORT
+;
+DSRTCENABLE	.SET	TRUE		; DSRTC: ENABLE DS-1302 CLOCK DRIVER (DSRTC.ASM)
+;
+ASCIENABLE	.SET	TRUE		; ASCI: ENABLE Z180 ASCI SERIAL DRIVER (ASCI.ASM)
+;
+ACIAENABLE	.SET	FALSE		; ACIA: ENABLE MOTOROLA 6850 ACIA DRIVER (ACIA.ASM)
+;
+SIOENABLE	.SET	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
+;
+FDENABLE	.SET	FALSE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
+FDMODE		.SET	FDMODE_RCWDC	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|DIDE|N8|DIO3]
+;
+IDEENABLE	.SET	TRUE		; IDE: ENABLE IDE DISK DRIVER (IDE.ASM)
+;
+PPIDEENABLE	.SET	TRUE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
+;
+SDENABLE	.SET	TRUE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
diff --git a/Source/HBIOS/Makefile b/Source/HBIOS/Makefile
index ea32f1c1..935f7b2d 100644
--- a/Source/HBIOS/Makefile
+++ b/Source/HBIOS/Makefile
@@ -13,6 +13,7 @@ else
 	OBJECTS += RCZ180_ext.rom RCZ180_ext.com RCZ180_ext.upd
 	OBJECTS += RCZ180_nat.rom RCZ180_nat.com RCZ180_nat.upd
 	OBJECTS += RCZ280_ext.rom RCZ280_ext.com RCZ280_ext.upd
+	OBJECTS += RCZ280_nat.rom RCZ280_nat.com RCZ280_nat.upd
 	OBJECTS += RCZ80_kio.rom RCZ80_kio.com RCZ80_kio.upd
 	OBJECTS += RCZ80_mt.rom RCZ80_mt.com RCZ80_mt.upd
 	OBJECTS += RCZ80_duart.rom RCZ80_duart.com RCZ80_duart.upd
@@ -23,6 +24,7 @@ else
 	OBJECTS += SCZ180_126.rom SCZ180_126.com SCZ180_126.upd
 	OBJECTS += SCZ180_130.rom SCZ180_130.com SCZ180_130.upd
 	OBJECTS += SCZ180_131.rom SCZ180_131.com SCZ180_131.upd
+	OBJECTS += SCZ180_140.rom SCZ180_140.com SCZ180_140.upd
 	OBJECTS += UNA_std.rom
 	OBJECTS += ZETA_std.rom ZETA_std.com ZETA_std.upd
 	OBJECTS += ZETA2_std.rom ZETA2_std.com ZETA2_std.upd
diff --git a/Source/HBIOS/dbgmon.asm b/Source/HBIOS/dbgmon.asm
index e838d850..665bdfbe 100644
--- a/Source/HBIOS/dbgmon.asm
+++ b/Source/HBIOS/dbgmon.asm
@@ -1412,12 +1412,12 @@ MON_STACK	.EQU	$
 		.ECHO	SLACK
 		.ECHO	" bytes.\n"
 ;
-; DBGMON CURRENTLY OCCUPIES $F000-$FDFF BECAUSE THE
-; HBIOS PROXY OCCUPIES $FE00-$FFFF.  HOWEVER THE DBGMON
+; DBGMON CURRENTLY OCCUPIES $F000 TO START OF HBX PROXY BECAUSE THE
+; HBIOS PROXY OCCUPIES THE TOP OF COMMON RAM.  HOWEVER THE DBGMON
 ; IMAGE MUST OCCUPY A FULL $1000 BYTES IN THE ROM.
-; BELOW WE JUST PAD OUT THE IMAGE BY $200 SO IT
+; BELOW WE JUST PAD OUT THE IMAGE SO IT
 ; OCCUPIES THE FULL $1000 BYTES IN ROM.
 ;
-		.FILL	$200,$00
+		.FILL	HBX_SIZ			; PAD FOR HBX SIZE
 ;
 		.END
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index b5ed6377..211afa24 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -247,6 +247,91 @@ CB_BIDROMDN	.DB	BID_ROMDN
 ;
 	.FILL	(HBX_IMG - $)		; FILL TO START OF PROXY IMAGE START
 	.ORG	HBX_LOC			; ADJUST FOR RELOCATION
+	
+;
+; Z280 BANK SELECTION (CALLED FROM PROXY)
+;
+#IF (MEMMGR == MM_Z280)
+;
+Z280_BNKSEL:
+	PUSH	HL
+	PUSH	DE
+	PUSH	BC
+	LD	L,$FF			; MMU PAGE I/O REG IS $FF
+	LD	C,8			; REG C POINTS TO I/O PAGE REGISTER
+	.DB	$ED,$6E			; OP CODE FOR LDCTL (C),HL
+	LD	E,0			; DE IS TEMPLATE
+	BIT	7,A
+	JR	Z,MMU_ROM		; TO ROM ROUTINE IF BIT 7 IS ZERO
+	RES	7,A
+	RR	A			; EXTRACT THE LSB
+	PUSH	AF			; SAVE THE CONDITION FLAG
+	OR	$08			; RAM BASE IS $080000
+	LD	D,A			; REG D CONTAINS THE HIGH BYTE TEMPLATE
+	POP	AF
+	JR	C,W_MMU1
+	JR	W_MMU0
+MMU_ROM:
+	OR	A			; CLEAR THE CARRY FLAG
+	RR	A			; EXTRACT THE LSB
+	LD	D,A			; REG D CONTAINS THE HIGH BYTE TEMPLATE
+	JR	C,W_MMU1
+W_MMU0:
+	LD	A,$10			; SYSTEM PAGE
+	OUT	(Z280_MMUPDRPTR),A
+	LD	C,Z280_MMUBLKMOV	; ACCESS BLOCK MOVE PORT SO POINTER WILL AUTOINCREM
+	LD	H,D			; GET TEMPLATE INTO HL
+	LD	L,$0A			; LOWEST 4K OF MEMORY
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$1A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$2A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$3A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$4A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$5A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$6A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	LD	L,$7A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	JR	W_MMU2
+W_MMU1:
+	LD	A,$10			; SYSTEM PAGE
+	OUT	(Z280_MMUPDRPTR),A
+	LD	C,Z280_MMUBLKMOV	; ACCESS BLOCK MOVE PORT SO POINTER WILL AUTOINCREM
+	LD	H,D			; GET TEMPLATE INTO HL
+	LD	L,$8A			; LOWEST 4K OF MEMORY
+	.DB	$ED,$BF			; OUTW (C),HL
+	LD	L,$9A			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL        
+	LD	L,$AA			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	LD	L,$BA			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	LD	L,$CA			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	LD	L,$DA			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	LD	L,$EA			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL  
+	LD	L,$FA			; MODIFY THE TEMPLATE FOR NEXT 4K
+	.DB	$ED,$BF			; OUTW (C),HL        
+W_MMU2:        
+	.DB    $ED,$65			; PCACHE
+	LD	L,0                     ; RESTORE I/O PAGE REG TO 0
+	LD	C,8
+	.DB	$ED,$6E			; LDCTL (C),HL
+	POP	BC
+	POP	DE
+	POP	HL
+	RET
+;
+#ENDIF
+;
+	.FILL	($FE00 - $)
 ;
 ; MEMORY LAYOUT:
 ;
@@ -373,8 +458,7 @@ HBX_ROM:
 	INC	A			;
 	OUT	(MPGSEL_1),A		; BANK_1: 16K - 32K
 #IF (CPUFAM == CPU_Z280)
-	;PCACHE				; PURGE CACHES
-	.DB	$ED,$65
+	.DB	$ED,$65			; PCACHE
 #ENDIF
 	RET				; DONE
 #ENDIF
@@ -412,8 +496,7 @@ HBX_BNKSEL1:
 	RET				; DONE
 #ENDIF
 #IF (MEMMGR == MM_Z280)
-	; TBD
-	RET				; DONE
+	JP	Z280_BNKSEL		; DO THE REAL WORK
 #ENDIF
 #IF (MEMMGR == MM_ZRC)
 	BIT	7,A			; BIT 7 SET REQUESTS RAM PAGE
@@ -444,10 +527,8 @@ HBX_BNKCPY:
 #IF (CPUFAM == CPU_Z280)
 	PUSH	IY
 	PUSH	BC
-	;LD	C,$00
 	LD	C,Z280_MSR
-	;LDCTL	IY,(C)
-	.DB	$FD,$ED,$66
+	.DB	$FD,$ED,$66		; LDCTL IY,(C)
 	POP	BC
 	PUSH	IY
 	DI
@@ -489,8 +570,7 @@ HBX_BC_SP	.EQU	$ - 2		; ... TO ORIGINAL VALUE
 	POP	IY
 	PUSH	BC
 	LD	C,Z280_MSR
-	;LDCTL	(C),IY
-	.DB	$FD,$ED,$6E
+	.DB	$FD,$ED,$6E		; LDCTL (C),IY
 	POP	BC
 	POP	IY
 #ELSE
@@ -769,7 +849,7 @@ HB_ENTRYTBL	.EQU	$
 	JP	HB_START		; HBIOS INITIALIZATION
 	JP	HB_DISPATCH		; VECTOR TO DISPATCHER
 ;
-HB_STKSIZ	.EQU	HB_ENTRYTBL + 256 - $
+HB_STKSIZ	.EQU	$100 - ($ & $FF)
 ;
 		.FILL	HB_STKSIZ,$FF	; USE REMAINDER OF PAGE FOR HBIOS STACK
 HB_STACK	.EQU	$		; TOP OF HBIOS STACK
@@ -857,18 +937,79 @@ HB_START:
 	LD	SP,HBX_LOC		; SETUP INITIAL STACK JUST BELOW HBIOS PROXY
 ;
 #IF (CPUFAM == CPU_Z280)
-	;LD	C,Z280_CCR		; CACHE CONTROL REGISTER
-	;LD	HL,$0060		; DISABLE INSTRUCTION CACHE
-	;;LDCTL	(C),HL			; SET IT (8 BITS)
-	;.DB	$ED,$6E
-	;;PCACHE			; PURGE ANY REMNANTS OF CACHE
-	;.DB	$ED,$65
-;
+	; SET MAXIMUM I/O WAIT STATES FOR NOW
 	LD	C,Z280_BTCR		; BUS TIMING AND CONTROL REGISTER
 	LD	HL,$0033		; 3 I/O WAIT STATES ADDED
-	;LD	HL,$00F3		; 3 I/O W/S & 3 INT ACK W/S
-	;LDCTL	(C),HL			; SET IT (8 BITS)
-	.DB	$ED,$6E
+	.DB	$ED,$6E			; LDCTL	(C),HL
+
+  #IF (MEMMGR == MM_Z280)
+  
+	; INITIALIZE MMU
+	; START BY SELECTING I/O PAGE $FF
+	LD	L,$FF			; MMU AND DMA PAGE I/O REG IS $FF
+	LD	C,$08			; REG C POINTS TO I/O PAGE REGISTER
+	.DB	$ED,$6E			; LDCTL	(C),HL
+;
+	; INITIALIZE ALL OF THE SYSTEM PAGE DESCRIPTORS WITH BLOCK MOVE
+	XOR	A			; FIRST USER PDR
+	OUT	(Z280_MMUPDRPTR),A	; SET THE PDR POINTER
+	LD	HL,Z280_PDRTBL		; START OF PDR VALUES TABLE
+	LD	C,Z280_MMUBLKMOV	; PDR BLOCK MOVE PORT
+	LD	B,16			; PROGRAM 16 PDRS
+	.DB	$ED,$93			; OTIRW
+;
+	; INITIALIZE ALL OF THE USER PAGE DESCRIPTORS WITH BLOCK MOVE
+	LD	A,$10			; FIRST SYSTEM PDR
+	OUT	(Z280_MMUPDRPTR),A	; SET THE PDR POINTER
+	LD	HL,Z280_PDRTBL		; START OF PDR VALUES TABLE
+	LD	C,Z280_MMUBLKMOV	; PDR BLOCK MOVE PORT
+	LD	B,16			; PROGRAM 16 PDRS
+	.DB	$ED,$93			; OTIRW
+;
+	; ENABLE MMU (SYSTEM AND USER TRANSLATION)
+	LD	C,Z280_MMUMCR		; MMU MASTER CONTROL REGISTER
+	LD	HL,$BBFF		; ENABLE USER & SYSTEM TRANSLATE
+	.DB	$ED,$BF			; OUTW (C),HL
+; 	
+	; RESTORE I/O PAGE TO $00
+	LD	L,$00			; NORMAL I/O REG IS $00
+	LD	C,$08			; REG C POINTS TO I/O PAGE REGISTER
+	.DB	$ED,$6E			; LDCTL	(C),HL
+;;
+;	; COPY Z280 BANK SELECTION CODE TO $FD80
+;	LD	HL,Z280_BNKSEL		; SOURCE
+;	LD	DE,$FD80		; DESTINATION
+;	LD	BC,Z280_BNKSELZ-Z280_BNKSEL ; BYTE COUNT TO COPY
+;	LDIR				; COPY
+;
+	DIAG(%11111110)
+;	JP	XZ280_BNKSELZ		; JUMP TO CODE CONTINUATION
+	JR	Z280_INITZ		; JUMP TO CODE CONTINUATION
+;
+Z280_PDRTBL:
+	; LOWER 32 K (BANKED)
+	.DW	($000 << 4) | $A
+	.DW	($001 << 4) | $A
+	.DW	($002 << 4) | $A
+	.DW	($003 << 4) | $A
+	.DW	($004 << 4) | $A
+	.DW	($005 << 4) | $A
+	.DW	($006 << 4) | $A
+	.DW	($007 << 4) | $A
+	; UPPER 32 K (COMMON)
+	.DW	($0F8 << 4) | $A
+	.DW	($0F9 << 4) | $A
+	.DW	($0FA << 4) | $A
+	.DW	($0FB << 4) | $A
+	.DW	($0FC << 4) | $A
+	.DW	($0FD << 4) | $A
+	.DW	($0FE << 4) | $A
+	.DW	($0FF << 4) | $A
+;
+Z280_INITZ:
+;
+  #ENDIF 
+;	
 #ENDIF
 ;
 #IF (CPUFAM == CPU_Z180)
@@ -1270,25 +1411,21 @@ HB_CPU2:
 #IF (CPUFAM == CPU_Z280)
 ;
 	LD	C,Z280_BTCR		; BUS TIMING AND CONTROL REG
-	;LDCTL	HL,(C)			; GET IT
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDCTL	HL,(C)
 	LD	A,L			; PUT IN A
 	AND	%00111100		; CLEAR DC AND I/O FIELDS
 	OR	Z280_INTWAIT << 6	; SET INT ACK WAIT STATES
 	OR	Z280_IOWAIT		; SET I/O WAIT STATES
 	LD	L,A			; BACK TO L
-	;LDCTL	(C),HL			; SET IT
-	.DB	$ED,$6E
+	.DB	$ED,$6E			; LDCTL	(C),HL
 ;
 	LD	C,Z280_BTIR		; BUS TIMING AND INIT REG
-	;LDCTL	HL,(C)			; GET IT
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDCTL	HL,(C)
 	LD	A,L			; PUT IN A
 	AND	%11110011		; CLEAR DC AND I/O FIELDS
 	OR	Z280_MEMWAIT << 2	; SET LOW MEM WAIT STATES
 	LD	L,A			; BACK TO L
-	;LDCTL	(C),HL			; SET IT
-	.DB	$ED,$6E
+	.DB	$ED,$6E			; LDCTL	(C),HL
 ;
 #ENDIF
 ;
@@ -1555,8 +1692,7 @@ HB_SPDTST:
 	CALL	PRTSTRD
 	.TEXT	", BUS @ $"
 	LD	C,Z280_BTIR		; BUS TIMING AND CTL REG
-	;LDCTL	HL,(C)			; GET IT
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDCTL	HL,(C)
 	LD	A,L			; MOVE TO A
 	AND	%00000011		; ISOLATE CS FIELD
 	LD	HL,(CB_CPUKHZ)		; GET CPU SPEED
@@ -1634,26 +1770,22 @@ HB_Z280BUS1:
 	PRTS("Z280: $")
 	PRTS("MSR=$")
 	LD	C,Z280_MSR		; MASTER STATUS REGISTER
-	;LDTCL	HL,(C)			; GET VALUE
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDCTL	HL,(C)
 	CALL	PRTHEXWORDHL
 	CALL	PC_SPACE
 	PRTS("BTCR=$")
 	LD	C,Z280_BTCR		; BUS TIMING AND CONTROL REGISTER
-	;LDTCL	HL,(C)			; GET VALUE
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDTCL	HL,(C)
 	CALL	PRTHEXWORDHL
 	CALL	PC_SPACE
 	PRTS("BTIR=$")
 	LD	C,Z280_BTIR		; BUS TIMING AND CONTROL REGISTER
-	;LDTCL	HL,(C)			; GET VALUE
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDTCL	HL,(C)
 	CALL	PRTHEXWORDHL
 	CALL	PC_SPACE
 	PRTS("CCR=$")
 	LD	C,Z280_CCR		; CACHE CONTROL REGISTER
-	;LDTCL	HL,(C)			; GET VALUE
-	.DB	$ED,$66
+	.DB	$ED,$66			; LDTCL	HL,(C)
 	CALL	PRTHEXWORDHL
 #ENDIF
 ;
@@ -2953,10 +3085,8 @@ SYS_PEEK:
 #IF (INTMODE == 1)
   #IF (CPUFAM == CPU_Z280)
 	PUSH	IY
-	;LD	C,$00
 	LD	C,Z280_MSR
-	;LDCTL	IY,(C)
-	.DB	$FD,$ED,$66
+	.DB	$FD,$ED,$66		; LDCTL	IY,(C)
 	PUSH	IY
 	DI
   #ELSE
@@ -2968,11 +3098,9 @@ SYS_PEEK:
 	CALL	HBX_PEEK		; IMPLEMENTED IN PROXY
 #IF (INTMODE == 1)
   #IF (CPUFAM == CPU_Z280)
-	;LD	C,$00
 	LD	C,Z280_MSR
 	POP	IY
-	;LDCTL	(C),IY
-	.DB	$FD,$ED,$6E
+	.DB	$FD,$ED,$6E		; LDCTL	(C),IY
 	POP	IY
   #ELSE
 	POP	AF
@@ -2995,8 +3123,7 @@ SYS_POKE:
   #IF (CPUFAM == CPU_Z280)
 	PUSH	IY
 	LD	C,Z280_MSR
-	;LDCTL	IY,(C)
-	.DB	$FD,$ED,$66
+	.DB	$FD,$ED,$66		; LDCTL	IY,(C)
 	PUSH	IY
 	DI
   #ELSE
@@ -3010,8 +3137,7 @@ SYS_POKE:
   #IF (CPUFAM == CPU_Z280)
 	LD	C,Z280_MSR
 	POP	IY
-	;LDCTL	(C),IY
-	.DB	$FD,$ED,$6E
+	.DB	$FD,$ED,$6E		; LDCTL	(C),IY
 	POP	IY
   #ELSE
 	POP	AF
diff --git a/Source/HBIOS/std.asm b/Source/HBIOS/std.asm
index 7a57020e..4643ce7b 100644
--- a/Source/HBIOS/std.asm
+++ b/Source/HBIOS/std.asm
@@ -443,7 +443,8 @@ BID_COM		.EQU	BID_RAMN	; COMMON BANK, UPPER 32K
 ;
 SYS_SIZ		.EQU	$3000			; COMBINED SIZE OF SYSTEM AREA (OS + HBIOS PROXY)
 HBBUF_SIZ	.EQU	1024			; INVARIANT HBIOS PHYSICAL DISK BUFFER, 1K
-HBX_SIZ		.EQU	$200			; HBIOS PROXY SIZE (SUBJECT TO CHANGE)
+;HBX_SIZ	.EQU	$200			; HBIOS PROXY SIZE (SUBJECT TO CHANGE)
+HBX_SIZ		.EQU	$200 + $80		; HBIOS PROXY SIZE (TEMP)
 CPM_SIZ		.EQU	SYS_SIZ - HBX_SIZ	; NET SIZE OF ALL OS COMPONENTS (EXCLUDING HBIOS PROXY)
 CCP_SIZ		.EQU	$800			; INVARIANT SIZE OF CCP
 BDOS_SIZ	.EQU	$E00			; INVARIANT SIZE OF BDOS
@@ -468,7 +469,7 @@ CPM_ENT		.EQU	CBIOS_LOC		; CPM ENTRY POINT (IN CBIOS)
 LDR_SIZ		.EQU	$0E00
 
 MON_LOC		.EQU	$F000			; LOCATION OF MONITOR FOR RUNNING SYSTEM
-MON_SIZ		.EQU	$0E00			; SIZE OF MONITOR BINARY IMAGE
+MON_SIZ		.EQU	$1000 - HBX_SIZ		; SIZE OF MONITOR BINARY IMAGE
 MON_END		.EQU	MON_LOC + MON_SIZ	; END OF MONITOR
 
 BAS_LOC		.EQU	$0200			; NASCOM BASIC
diff --git a/Source/HBIOS/z280.inc b/Source/HBIOS/z280.inc
index 25e280e0..802af93d 100644
--- a/Source/HBIOS/z280.inc
+++ b/Source/HBIOS/z280.inc
@@ -1,5 +1,5 @@
 ;
-; Z280 REGISTERS
+; Z280 CPU CONTROL REGISTERS (VIA LDCTL)
 ;
 Z280_MSR	.EQU	$00	; MASTER STATUS REG
 Z280_ISR	.EQU	$16	; INTERRUPT STATUS REG
@@ -11,3 +11,11 @@ Z280_SLR	.EQU	$04	; STACK LIMIT REG
 Z280_TCR	.EQU	$10	; TRAP CONTROL REG
 Z280_CCR	.EQU	$12	; CACHE CONTROL REG
 Z280_LAR	.EQU	$14	; LOCAL ADDRESS REG
+;
+; Z280 MMU REGISTERS (I/O PAGE $FF, I/O ADDRESS $FF**NN)
+;
+Z280_MMUMCR	.EQU	$F0	; Z280 MMU MASTER CONTROL REG
+Z280_MMUPDRPTR	.EQU	$F1	; Z280 MMU PDR POINTER REG
+Z280_MMUINV	.EQU	$F2	; Z280 MMU INVALIDATION PORT
+Z280_MMUBLKMOV	.EQU	$F4	; Z280 MMU BLOCK MOVE PORT
+Z280_MMUPDR	.EQU	$F5	; Z280 MMU PDR PORT
diff --git a/Source/ver.inc b/Source/ver.inc
index 6830eb97..41fc494e 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,4 +2,4 @@
 #DEFINE	RMN	1
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.1.1-pre.28"
+#DEFINE BIOSVER	"3.1.1-pre.29"
diff --git a/Source/ver.lib b/Source/ver.lib
index 9bd6e1f1..ec2a37e5 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	1
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.1.1-pre.28"
+	db	"3.1.1-pre.29"
 	endm