diff --git a/Doc/ChangeLog.txt b/Doc/ChangeLog.txt
index 1487963f..b411b106 100644
--- a/Doc/ChangeLog.txt
+++ b/Doc/ChangeLog.txt
@@ -1,6 +1,8 @@
 Version 3.3
 -----------
-- Support Front Panel switches
+- WBW: Support Front Panel switches
+- A?C: Preliminary support for Z80-Retro
+- A?C: Support for SD PIO
 
 Version 3.2.1
 -------------
diff --git a/Doc/RomWBW Applications.pdf b/Doc/RomWBW Applications.pdf
index 8f372f58..81825a1f 100644
Binary files a/Doc/RomWBW Applications.pdf and b/Doc/RomWBW Applications.pdf differ
diff --git a/Doc/RomWBW Disk Catalog.pdf b/Doc/RomWBW Disk Catalog.pdf
index 1bc3d0ef..bb1fc47d 100644
Binary files a/Doc/RomWBW Disk Catalog.pdf and b/Doc/RomWBW Disk Catalog.pdf differ
diff --git a/Doc/RomWBW Errata.pdf b/Doc/RomWBW Errata.pdf
index e4ed09a8..b7a78e03 100644
Binary files a/Doc/RomWBW Errata.pdf and b/Doc/RomWBW Errata.pdf differ
diff --git a/Doc/RomWBW ROM Applications.pdf b/Doc/RomWBW ROM Applications.pdf
index 67200b16..41a763f0 100644
Binary files a/Doc/RomWBW ROM Applications.pdf and b/Doc/RomWBW ROM Applications.pdf differ
diff --git a/Doc/RomWBW System Guide.pdf b/Doc/RomWBW System Guide.pdf
index 56d47ed9..49a28f87 100644
Binary files a/Doc/RomWBW System Guide.pdf and b/Doc/RomWBW System Guide.pdf differ
diff --git a/Doc/RomWBW User Guide.pdf b/Doc/RomWBW User Guide.pdf
index 4ef095ec..4d969fc3 100644
Binary files a/Doc/RomWBW User Guide.pdf and b/Doc/RomWBW User Guide.pdf differ
diff --git a/ReadMe.md b/ReadMe.md
index 78875f53..965a73cf 100644
--- a/ReadMe.md
+++ b/ReadMe.md
@@ -3,7 +3,7 @@
 **RomWBW ReadMe** \
 Version 3.3 \
 Wayne Warthen  ([wwarthen@gmail.com](mailto:wwarthen@gmail.com)) \
-14 Apr 2023
+16 Apr 2023
 
 # Overview
 
diff --git a/ReadMe.txt b/ReadMe.txt
index a896b641..9a70f421 100644
--- a/ReadMe.txt
+++ b/ReadMe.txt
@@ -1,6 +1,6 @@
 RomWBW ReadMe
 Wayne Warthen (wwarthen@gmail.com)
-14 Apr 2023
+16 Apr 2023
 
 
 
diff --git a/Source/Doc/Graphics/Panel.pdf b/Source/Doc/Graphics/Panel.pdf
new file mode 100644
index 00000000..2ec8d559
Binary files /dev/null and b/Source/Doc/Graphics/Panel.pdf differ
diff --git a/Source/Doc/Graphics/Panel.png b/Source/Doc/Graphics/Panel.png
new file mode 100644
index 00000000..488d258f
Binary files /dev/null and b/Source/Doc/Graphics/Panel.png differ
diff --git a/Source/Doc/Graphics/Panel.vsdx b/Source/Doc/Graphics/Panel.vsdx
new file mode 100644
index 00000000..2f760f34
Binary files /dev/null and b/Source/Doc/Graphics/Panel.vsdx differ
diff --git a/Source/Doc/UserGuide.md b/Source/Doc/UserGuide.md
index 24245f19..9088eac6 100644
--- a/Source/Doc/UserGuide.md
+++ b/Source/Doc/UserGuide.md
@@ -201,6 +201,7 @@ below, **carefully** pick the appropriate ROM image for your hardware.
 | [Z80 ZRC CPU Module]^7^                                        | RCBus   | RCZ80_zrc.rom      | 115200        |
 | [Z280 ZZRCC CPU Module]^7^                                     | RCBus   | RCZ280_zzrc.rom    | 115200        |
 | [Z280 ZZ80MB SBC]^7^                                           | RCBus   | RCZ280_zz80mb.rom  | 115200        |
+| [Z80-Retro SBC]^8^                                             | -       | Z80RETRO_std.rom   | 38400         |
 
 | ^1^Designed by Andrew Lynch
 | ^2^Designed by Sergey Kiselev
@@ -209,6 +210,7 @@ below, **carefully** pick the appropriate ROM image for your hardware.
 | ^5^Designed by Stephen Cousins
 | ^6^Designed by Steve Garcia
 | ^7^Designed by Bill Shen
+| ^8^Designed by Peter Wilson
 
 RCBus refers to Spencer Owen's RC2014 bus specification and derivatives
 including RC26, RC40, RC80, and BP80.
@@ -782,6 +784,55 @@ The use of diagnostic levels above 4 are really intended only for
 software developers.  I do not recommend changing this under
 normal circumstances.
 
+## Front Panel
+
+RomWBW supports the concept of a simple front panel.  The following 
+image is a conceptual view of such a front panel.  If your system has a 
+front panel, it should look similar to the [RomWBW Front Panel](#panel).
+
+![RomWBW Front Panel](Graphics/Panel){#panel width=50% }
+
+The LEDs in the top row of the panel are used for multiple purposes.
+They are initially used to display the progress of the
+system boot.  This may help in diagnosing a hardware or configuration
+issue in a system that does not progress far enough to display text
+output on the console.  The meaning of the LEDs is:
+
+|            |                              |
+|------------|------------------------------|
+| `O-------` | System Boot has started      |
+| `OO------` | Common RAM bank activated    |
+| `OOO-----` | HBIOS transitioned to RAM    |
+| `OOOO----` | Basic initialization done    |
+| `OOOOO---` | CPU detection complete       |
+| `OOOOOO--` | System timer configured      |
+| `OOOOOOO-` | Pre-console device init done |
+| `OOOOOOOO` | Console activation           |
+
+Once the system has booted, the LEDs are used to indicate disk device
+activity.  Each LED numbered 7-0 represents disk units 7-0.  As each
+disk device performs I/O, the LED will light.
+
+The second row of the front panel is composed of switches that allow
+you to control a few aspects of the system startup.
+
+The first two switches affect the device used as the console initially.
+Setting the CRT/Serial switch will cause the system to boot directly 
+to an attached CRT device (if available).  Setting the Pri/Sec switch 
+will cause the system to boot to the secondary Serial or CRT device 
+(depending on the setting of the first switch).
+
+The final six switches allow you to cause the system to automatically
+boot into a desired function.  The Auto/Menu switch must be set to
+enable this, otherwise the normal ROM Loader prompt will be used.
+If the Disk/ROM switch is not set, then you can use the last 3
+switches to select a ROM app to auto-start.  If the Disk/ROM switch is
+set, then the system will attempt a disk boot based on the following
+switches.  The Floppy/Hard switch can be used to boot to a Floppy or
+Hard Disk.  In either case, the first Floppy or Hard Disk will be used
+for the boot.  If a Hard Disk boot is selected, then the last three
+switches can be used to select any of the first 8 slices.
+
 # Disk Management
 
 The systems supported by RomWBW all have the ability to use persistent
@@ -3808,6 +3859,21 @@ the RomWBW HBIOS configuration.
 
 `\clearpage`{=latex}
 
+### Z80-Retro SBC
+
+|                   |                  |
+|-------------------|------------------|
+| ROM Image File    | Z80RETRO_std.rom |
+| Console Baud Rate | 38400            |
+| Interrupts        | Mode 2           |
+
+ - CPU speed is assumed to be 14.7456 MHz
+ - Hardware auto-detected:
+   - SIO Serial Interface Module
+   - Onboard CTC
+
+`\clearpage`{=latex}
+
 ## Appendix B - Device Summary
 
 The table below briefly describes each of the possible devices that
diff --git a/Source/HBIOS/Build.cmd b/Source/HBIOS/Build.cmd
index 802e6182..bfda5355 100644
--- a/Source/HBIOS/Build.cmd
+++ b/Source/HBIOS/Build.cmd
@@ -223,5 +223,6 @@ call Build SCZ180 sc503 || exit /b
 call Build DYNO std || exit /b
 call Build UNA std || exit /b
 call Build RPH std || exit /b
+call Build Z80RETRO std || exit /b
 
 goto :eof
diff --git a/Source/HBIOS/Build.ps1 b/Source/HBIOS/Build.ps1
index 518dbae4..5e2c2065 100644
--- a/Source/HBIOS/Build.ps1
+++ b/Source/HBIOS/Build.ps1
@@ -27,7 +27,7 @@ $ErrorAction = 'Stop'
 # UNA BIOS is simply imbedded, it is not built here.
 #
 
-$PlatformListZ80 = "SBC", "MBC", "ZETA", "ZETA2", "RCZ80", "UNA"
+$PlatformListZ80 = "SBC", "MBC", "ZETA", "ZETA2", "RCZ80", "Z80RETRO", "UNA"
 $PlatformListZ180 = "N8", "MK4", "RCZ180", "SCZ180", "DYNO", "RPH"
 $PlatformListZ280 = "RCZ280"
 
diff --git a/Source/HBIOS/Build.sh b/Source/HBIOS/Build.sh
index 69c1c1b5..3b9c46b3 100755
--- a/Source/HBIOS/Build.sh
+++ b/Source/HBIOS/Build.sh
@@ -38,6 +38,7 @@ if [ "${ROM_PLATFORM}" == "dist" ] ; then
 	ROM_PLATFORM="SCZ180"; ROM_CONFIG="sc140"; bash Build.sh
 	ROM_PLATFORM="SCZ180"; ROM_CONFIG="sc503"; bash Build.sh
 	ROM_PLATFORM="UNA"; ROM_CONFIG="std"; bash Build.sh
+	ROM_PLATFORM="Z80RETRO"; ROM_CONFIG="std"; bash Build.sh
 	ROM_PLATFORM="ZETA"; ROM_CONFIG="std"; bash Build.sh
 	ROM_PLATFORM="ZETA2"; ROM_CONFIG="std"; bash Build.sh
 	exit
diff --git a/Source/HBIOS/Config/RCZ80_std.asm b/Source/HBIOS/Config/RCZ80_std.asm
index e0002a56..3d759f28 100644
--- a/Source/HBIOS/Config/RCZ80_std.asm
+++ b/Source/HBIOS/Config/RCZ80_std.asm
@@ -55,6 +55,7 @@ FDMODE		.SET	FDMODE_RCWDC	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|ZETA2|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	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
+SDMODE		.SET	SDMODE_PIO	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDCNT		.SET	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT SC ONLY
 ;
 PRPENABLE	.SET	FALSE		; PRP: ENABLE ECB PROPELLER IO BOARD DRIVER (PRP.ASM)
diff --git a/Source/HBIOS/Config/Z80RETRO_std.asm b/Source/HBIOS/Config/Z80RETRO_std.asm
new file mode 100644
index 00000000..0e3c86d0
--- /dev/null
+++ b/Source/HBIOS/Config/Z80RETRO_std.asm
@@ -0,0 +1,35 @@
+;
+;==================================================================================================
+;   ZETA2 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	BOOT_DEFAULT	"H"		; DEFAULT BOOT LOADER CMD ON <CR> OR AUTO BOOT
+;
+#include "cfg_z80retro.asm"
+;
+CPUOSC		.SET	14745600	; CPU OSC FREQ IN MHZ
+INTMODE		.SET	2		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
+CRTACT		.SET	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+;
+UARTENABLE	.SET	FALSE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+;
+SDENABLE	.SET	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
diff --git a/Source/HBIOS/cfg_dyno.asm b/Source/HBIOS/cfg_dyno.asm
index 011ccee1..4c0a9cb1 100644
--- a/Source/HBIOS/cfg_dyno.asm
+++ b/Source/HBIOS/cfg_dyno.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_DYNO	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_DYNO	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z180	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -148,7 +148,7 @@ SIOENABLE	.EQU	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	2		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	7372800		; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	SER_115200_8N1	; SIO 0A: SERIAL LINE CONFIG
@@ -156,7 +156,7 @@ SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 SIO0BCLK	.EQU	7372800		; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0BCFG	.EQU	SER_115200_8N1	; SIO 0B: SERIAL LINE CONFIG
 SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
-SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
 SIO1ACLK	.EQU	7372800		; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO1ACFG	.EQU	SER_115200_8N1	; SIO 1A: SERIAL LINE CONFIG
@@ -227,7 +227,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_master.asm b/Source/HBIOS/cfg_master.asm
index 1ccf685c..9dacda53 100644
--- a/Source/HBIOS/cfg_master.asm
+++ b/Source/HBIOS/cfg_master.asm
@@ -12,7 +12,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_SBC		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_SBC		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -196,7 +196,7 @@ SIOENABLE	.EQU	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	2		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	CPUOSC		; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -204,7 +204,7 @@ SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 SIO0BCLK	.EQU	CPUOSC		; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0BCFG	.EQU	DEFSERCFG	; SIO 0B: SERIAL LINE CONFIG
 SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
-SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
 SIO1ACLK	.EQU	CPUOSC		; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO1ACFG	.EQU	DEFSERCFG	; SIO 1A: SERIAL LINE CONFIG
@@ -282,7 +282,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_NONE	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_NONE	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_mbc.asm b/Source/HBIOS/cfg_mbc.asm
index 5b5c6875..361bd17c 100644
--- a/Source/HBIOS/cfg_mbc.asm
+++ b/Source/HBIOS/cfg_mbc.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_MBC		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_MBC		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -134,7 +134,7 @@ SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$B0		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	(4915200/8)	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -211,7 +211,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_JUHA	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_JUHA	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index babaf468..e7e3a929 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_MK4		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_MK4		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z180	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -145,7 +145,7 @@ SIOENABLE	.EQU	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$B0		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	(4915200/8)	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -221,7 +221,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	TRUE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_MK4	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_MK4	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index b9890a87..fde1fbeb 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_N8		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_N8		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z180	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -147,7 +147,7 @@ SIOENABLE	.EQU	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$B0		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	(4915200/8)	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -223,7 +223,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	TRUE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_CSIO	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT]
+SDMODE		.EQU	SDMODE_CSIO	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	N8_PPI0		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_rcz180.asm b/Source/HBIOS/cfg_rcz180.asm
index a0fa0b59..47b36d42 100644
--- a/Source/HBIOS/cfg_rcz180.asm
+++ b/Source/HBIOS/cfg_rcz180.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_RCZ180	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_RCZ180	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z180	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -148,7 +148,7 @@ SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	2		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	7372800		; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	SER_115200_8N1	; SIO 0A: SERIAL LINE CONFIG
@@ -156,7 +156,7 @@ SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 SIO0BCLK	.EQU	7372800		; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0BCFG	.EQU	SER_115200_8N1	; SIO 0B: SERIAL LINE CONFIG
 SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
-SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
 SIO1ACLK	.EQU	7372800		; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO1ACFG	.EQU	SER_115200_8N1	; SIO 1A: SERIAL LINE CONFIG
@@ -227,7 +227,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_MT	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_MT	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	2		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_rcz280.asm b/Source/HBIOS/cfg_rcz280.asm
index 8d8a0a92..38a6dfee 100644
--- a/Source/HBIOS/cfg_rcz280.asm
+++ b/Source/HBIOS/cfg_rcz280.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_RCZ280	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_RCZ280	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z280	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -158,7 +158,7 @@ SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	2		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	7372800		; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -166,7 +166,7 @@ SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 SIO0BCLK	.EQU	7372800		; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0BCFG	.EQU	DEFSERCFG	; SIO 0B: SERIAL LINE CONFIG
 SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
-SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
 SIO1ACLK	.EQU	7372800		; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO1ACFG	.EQU	DEFSERCFG	; SIO 1A: SERIAL LINE CONFIG
@@ -237,7 +237,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_MT	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_MT	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	2		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_rcz80.asm b/Source/HBIOS/cfg_rcz80.asm
index e04982b6..c11e769c 100644
--- a/Source/HBIOS/cfg_rcz80.asm
+++ b/Source/HBIOS/cfg_rcz80.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_RCZ80	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_RCZ80	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -152,7 +152,7 @@ SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	2		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	CPUOSC		; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -160,7 +160,7 @@ SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 SIO0BCLK	.EQU	CPUOSC		; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0BCFG	.EQU	DEFSERCFG	; SIO 0B: SERIAL LINE CONFIG
 SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
-SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
 SIO1ACLK	.EQU	CPUOSC		; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO1ACFG	.EQU	DEFSERCFG	; SIO 1A: SERIAL LINE CONFIG
@@ -231,7 +231,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_MT	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_MT	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	2		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_rph.asm b/Source/HBIOS/cfg_rph.asm
index 529274a3..738517f5 100644
--- a/Source/HBIOS/cfg_rph.asm
+++ b/Source/HBIOS/cfg_rph.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_RPH		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_RPH		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z180	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	TRUE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -212,7 +212,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_CSIO	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_CSIO	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	RPH_PPI0	; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_sbc.asm b/Source/HBIOS/cfg_sbc.asm
index 2bd8a81d..f52dbc14 100644
--- a/Source/HBIOS/cfg_sbc.asm
+++ b/Source/HBIOS/cfg_sbc.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_SBC		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_SBC		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -134,7 +134,7 @@ SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$B0		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	(4915200/8)	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
@@ -211,7 +211,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_JUHA	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_JUHA	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_scz180.asm b/Source/HBIOS/cfg_scz180.asm
index e99e0b7b..64ac08c6 100644
--- a/Source/HBIOS/cfg_scz180.asm
+++ b/Source/HBIOS/cfg_scz180.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_SCZ180	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_SCZ180	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z180	; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -148,7 +148,7 @@ SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
 SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
 SIOCNT		.EQU	2		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0MODE	.EQU	SIOMODE_RC	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
 SIO0ACLK	.EQU	7372800		; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0ACFG	.EQU	SER_115200_8N1	; SIO 0A: SERIAL LINE CONFIG
@@ -156,7 +156,7 @@ SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 SIO0BCLK	.EQU	7372800		; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO0BCFG	.EQU	SER_115200_8N1	; SIO 0B: SERIAL LINE CONFIG
 SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
-SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO1MODE	.EQU	SIOMODE_RC	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
 SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
 SIO1ACLK	.EQU	7372800		; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
 SIO1ACFG	.EQU	SER_115200_8N1	; SIO 1A: SERIAL LINE CONFIG
@@ -227,7 +227,7 @@ PPIDE2A8BIT	.EQU	FALSE		; PPIDE 2A (MASTER): 8 BIT XFER
 PPIDE2B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	TRUE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_SC	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_SC	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_una.asm b/Source/HBIOS/cfg_una.asm
index 926e7917..8555aed5 100644
--- a/Source/HBIOS/cfg_una.asm
+++ b/Source/HBIOS/cfg_una.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "../UBIOS/ubios.inc"
 ;
-;PLATFORM	.EQU	PLT_UNA		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+;PLATFORM	.EQU	PLT_UNA		; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_UNA	; HARDWARE BIOS: BIOS_[WBW|UNA]
 ;
diff --git a/Source/HBIOS/cfg_z80retro.asm b/Source/HBIOS/cfg_z80retro.asm
new file mode 100644
index 00000000..90c3436b
--- /dev/null
+++ b/Source/HBIOS/cfg_z80retro.asm
@@ -0,0 +1,224 @@
+;
+;==================================================================================================
+;   ROMWBW 2.X CONFIGURATION DEFAULTS FOR SIMPLE Z80 RETRO
+;==================================================================================================
+;
+; THIS FILE CONTAINS THE FULL SET OF DEFAULT CONFIGURATION SETTINGS FOR THE PLATFORM
+; INDICATED ABOVE. THIS FILE SHOULD *NOT* NORMALLY BE CHANGED.	INSTEAD, YOU SHOULD
+; OVERRIDE ANY SETTINGS YOU WANT USING A CONFIGURATION FILE IN THE CONFIG DIRECTORY
+; UNDER THIS DIRECTORY.
+;
+; THIS FILE CAN BE CONSIDERED A REFERENCE THAT LISTS ALL POSSIBLE CONFIGURATION SETTINGS
+; FOR THE PLATFORM.
+;
+#DEFINE PLATFORM_NAME "Z80Retro", " [", CONFIG, "]"
+;
+#INCLUDE "hbios.inc"
+;
+PLATFORM	.EQU	PLT_Z80RETRO	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
+CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
+BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
+BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
+HBIOS_MUTEX	.EQU	FALSE		; ENABLE REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
+USELZSA2	.EQU	TRUE		; ENABLE FONT COMPRESSION
+TICKFREQ	.EQU	50		; DESIRED PERIODIC TIMER INTERRUPT FREQUENCY (HZ)
+;
+BOOT_TIMEOUT	.EQU	-1		; AUTO BOOT TIMEOUT IN SECONDS, -1 TO DISABLE, 0 FOR IMMEDIATE
+BOOT_DELAY	.EQU	0		; FIXED BOOT DELAY IN SECONDS PRIOR TO CONSOLE OUTPUT
+;
+CPUSPDCAP	.EQU	SPD_FIXED	; CPU SPEED CHANGE CAPABILITY SPD_FIXED|SPD_HILO
+CPUSPDDEF	.EQU	SPD_HIGH	; CPU SPEED DEFAULT SPD_UNSUP|SPD_HIGH|SPD_LOW
+CPUOSC		.EQU	14745600	; CPU OSC FREQ IN MHZ
+INTMODE		.EQU	2		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2, 3=MODE 3 (Z280)
+DEFSERCFG	.EQU	SER_38400_8N1	; DEFAULT SERIAL LINE CONFIG (SEE STD.ASM)
+;
+RAMSIZE		.EQU	512		; SIZE OF RAM IN KB (MUST MATCH YOUR HARDWARE!!!)
+ROMSIZE		.EQU	512		; SIZE OF ROM IN KB (MUST MATCH YOUR HARDWARE!!!)
+ROMSIZE_CHK	.EQU	0		; ROMSIZE VALUE VERIFICATION (0=DISABLED)
+MEMMGR		.EQU	MM_Z2		; MEMORY MANAGER: MM_[SBC|Z2|N8|Z180|Z280|MBC|RPH]
+MPGSEL_0	.EQU	$60		; Z2 MEM MGR BANK 0 PAGE SELECT REG (WRITE ONLY)
+MPGSEL_1	.EQU	$61		; Z2 MEM MGR BANK 1 PAGE SELECT REG (WRITE ONLY)
+MPGSEL_2	.EQU	$62		; Z2 MEM MGR BANK 2 PAGE SELECT REG (WRITE ONLY)
+MPGSEL_3	.EQU	$63		; Z2 MEM MGR BANK 3 PAGE SELECT REG (WRITE ONLY)
+MPGENA		.EQU	$64		; Z2 MEM MGR PAGING ENABLE REGISTER (BIT 0, WRITE ONLY)
+;
+RTCIO		.EQU	$70		; RTC LATCH REGISTER ADR
+;
+KIOENABLE	.EQU	FALSE		; ENABLE ZILOG KIO SUPPORT
+KIOBASE		.EQU	$80		; KIO BASE I/O ADDRESS
+;
+CTCENABLE	.EQU	TRUE		; ENABLE ZILOG CTC SUPPORT
+CTCDEBUG	.EQU	FALSE		; ENABLE CTC DRIVER DEBUG OUTPUT
+CTCBASE		.EQU	$40		; CTC BASE I/O ADDRESS
+CTCTIMER	.EQU	FALSE		; ENABLE CTC PERIODIC TIMER (too fast for RomWBW right now)
+CTCMODE		.EQU	CTCMODE_CTR	; CTC MODE: CTCMODE_[NONE|CTR|TIM16|TIM256]
+CTCPRE		.EQU	256		; PRESCALE CONSTANT (1-256)
+CTCPRECH	.EQU	0		; PRESCALE CHANNEL (0-3)
+CTCTIMCH	.EQU	1		; TIMER CHANNEL (0-3)
+CTCOSC		.EQU	7372800		; CTC CLOCK FREQUENCY
+;
+EIPCENABLE	.EQU	FALSE		; EIPC: ENABLE Z80 EIPC (Z84C15) INITIALIZATION
+;
+SKZENABLE	.EQU	FALSE		; ENABLE SERGEY'S Z80-512K FEATURES
+;
+WDOGMODE	.EQU	WDOG_NONE	; WATCHDOG MODE: WDOG_[NONE|EZZ80|SKZ]
+;
+FPENABLE	.EQU	FALSE		; ENABLES FRONT PANEL SWITCHES
+FPBASE		.EQU	$00		; FRONT PANEL I/O PORT BASE ADDRESS
+DIAGENABLE	.EQU	FALSE		; ENABLES OUTPUT TO 8 BIT LED DIAGNOSTIC PORT
+DIAGPORT	.EQU	$00		; DIAGNOSTIC PORT ADDRESS
+DIAGDISKIO	.EQU	TRUE		; ENABLES DISK I/O ACTIVITY ON DIAGNOSTIC LEDS
+DIAGLVL		.EQU	DL_CRITICAL	; ERROR LEVEL REPORTING
+;
+LEDENABLE	.EQU	FALSE		; ENABLES STATUS LED
+LEDMODE		.EQU	LEDMODE_RTC	; LEDMODE_[STD|RTC]
+LEDPORT		.EQU	$00		; STATUS LED PORT ADDRESS
+LEDDISKIO	.EQU	TRUE		; ENABLES DISK I/O ACTIVITY ON STATUS LED
+;
+DSKYENABLE	.EQU	FALSE		; ENABLES DSKY
+DSKYMODE	.EQU	DSKYMODE_V1	; DSKY VERSION: DSKYMODE_[V1|NG]
+DSKYPPIBASE	.EQU	$60		; BASE I/O ADDRESS OF DSKY PPI
+DSKYOSC		.EQU	3000000		; OSCILLATOR FREQ FOR DSKYNG (IN HZ)
+;
+BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
+VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
+ANSITRACE	.EQU	1		; ANSI DRIVER TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
+MKYENABLE	.EQU	FALSE		; MSX 5255 PPI KEYBOARD COMPATIBLE DRIVER (REQUIRES TMS VDA DRIVER)
+;
+DSRTCENABLE	.EQU	FALSE		; DSRTC: ENABLE DS-1302 CLOCK DRIVER (DSRTC.ASM)
+DSRTCMODE	.EQU	DSRTCMODE_STD	; DSRTC: OPERATING MODE: DSRTC_[STD|MFPIC]
+DSRTCCHG	.EQU	FALSE		; DSRTC: FORCE BATTERY CHARGE ON (USE WITH CAUTION!!!)
+;
+DS1501RTCENABLE	.EQU	FALSE		; DS1501RTC: ENABLE DS-1501 CLOCK DRIVER (DS1501RTC.ASM)
+DS1501RTC_BASE	.EQU	$50		; DS1501RTC: I/O BASE ADDRESS
+;
+BQRTCENABLE	.EQU	FALSE		; BQRTC: ENABLE BQ4845 CLOCK DRIVER (BQRTC.ASM)
+BQRTC_BASE	.EQU	$50		; BQRTC: I/O BASE ADDRESS
+;
+INTRTCENABLE	.EQU	FALSE		; ENABLE PERIODIC INTERRUPT CLOCK DRIVER (INTRTC.ASM)
+;
+RP5RTCENABLE	.EQU	FALSE		; RP5C01 RTC BASED CLOCK (RP5RTC.ASM)
+;
+HTIMENABLE	.EQU	FALSE		; ENABLE SIMH TIMER SUPPORT
+SIMRTCENABLE	.EQU	FALSE		; ENABLE SIMH CLOCK DRIVER (SIMRTC.ASM)
+;
+DS7RTCENABLE	.EQU	FALSE		; DS7RTC: ENABLE DS-1307 I2C CLOCK DRIVER (DS7RTC.ASM)
+DS7RTCMODE	.EQU	DS7RTCMODE_PCF	; DS7RTC: OPERATING MODE: DS7RTC_[PCF]
+;
+DUARTENABLE	.EQU	FALSE		; DUART: ENABLE 2681/2692 SERIAL DRIVER (DUART.ASM)
+;
+UARTENABLE	.EQU	FALSE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+UARTOSC		.EQU	1843200		; UART: OSC FREQUENCY IN MHZ
+UARTINTS	.EQU	FALSE		; UART: INCLUDE INTERRUPT SUPPORT UNDER IM1/2/3
+UARTCFG		.EQU	DEFSERCFG	; UART: LINE CONFIG FOR UART PORTS
+UARTCASSPD	.EQU	SER_300_8N1	; UART: ECB CASSETTE UART DEFAULT SPEED
+UARTSBC		.EQU	TRUE		; UART: AUTO-DETECT SBC/ZETA ONBOARD UART
+UARTSBCFORCE	.EQU	FALSE		; UART: FORCE DETECTION OF SBC UART (FOR SIMH)
+UARTCAS		.EQU	FALSE		; UART: AUTO-DETECT ECB CASSETTE UART
+UARTMFP		.EQU	FALSE		; UART: AUTO-DETECT MF/PIC UART
+UART4		.EQU	FALSE		; UART: AUTO-DETECT 4UART UART
+UARTRC		.EQU	FALSE		; UART: AUTO-DETECT RC UART
+UARTDUAL	.EQU	FALSE		; UART: AUTO-DETECT DUAL UART
+;
+ASCIENABLE	.EQU	FALSE		; ASCI: ENABLE Z180 ASCI SERIAL DRIVER (ASCI.ASM)
+;
+Z2UENABLE	.EQU	FALSE		; Z2U: ENABLE Z280 UART SERIAL DRIVER (Z2U.ASM)
+;
+ACIAENABLE	.EQU	FALSE		; ACIA: ENABLE MOTOROLA 6850 ACIA DRIVER (ACIA.ASM)
+;
+SIOENABLE	.EQU	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
+SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
+SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
+SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
+SIO0MODE	.EQU	SIOMODE_Z80R	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
+SIO0BASE	.EQU	$80		; SIO 0: REGISTERS BASE ADR
+SIO0ACLK	.EQU	CPUOSC/2	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
+SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
+SIO0BCLK	.EQU	CPUOSC/2	; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO0BCFG	.EQU	DEFSERCFG	; SIO 0B: SERIAL LINE CONFIG
+SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
+SIO1MODE	.EQU	SIOMODE_Z80R	; SIO 1: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP|Z80R]
+SIO1BASE	.EQU	$84		; SIO 1: REGISTERS BASE ADR
+SIO1ACLK	.EQU	CPUOSC/2	; SIO 1A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO1ACFG	.EQU	DEFSERCFG	; SIO 1A: SERIAL LINE CONFIG
+SIO1ACTCC	.EQU	-1		; SIO 1A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
+SIO1BCLK	.EQU	CPUOSC/2	; SIO 1B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO1BCFG	.EQU	DEFSERCFG	; SIO 1B: SERIAL LINE CONFIG
+SIO1BCTCC	.EQU	-1		; SIO 1B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
+;
+XIOCFG		.EQU	DEFSERCFG	; XIO: SERIAL LINE CONFIG
+;
+VDUENABLE	.EQU	FALSE		; VDU: ENABLE VDU VIDEO/KBD DRIVER (VDU.ASM)
+CVDUENABLE	.EQU	FALSE		; CVDU: ENABLE CVDU VIDEO/KBD DRIVER (CVDU.ASM)
+GDCENABLE	.EQU	FALSE		; GDC: ENABLE 7220 GDC VIDEO/KBD DRIVER (GDC.ASM)
+TMSENABLE	.EQU	FALSE		; TMS: ENABLE TMS9918 VIDEO/KBD DRIVER (TMS.ASM)
+TMSMODE		.EQU	TMSMODE_NONE	; TMS: DRIVER MODE: TMSMODE_[SCG|N8|MBC|MSX|MSX9958|MSXKBD|COLECO]
+TMSTIMENABLE	.EQU	FALSE		; TMS: ENABLE TIMER INTERRUPTS (REQUIRES IM1)
+VGAENABLE	.EQU	FALSE		; VGA: ENABLE VGA VIDEO/KBD DRIVER (VGA.ASM)
+;
+MDENABLE	.EQU	TRUE		; MD: ENABLE MEMORY (ROM/RAM) DISK DRIVER (MD.ASM)
+MDROM		.EQU	TRUE		; MD: ENABLE ROM DISK
+MDRAM		.EQU	TRUE		; MD: ENABLE RAM DISK
+MDTRACE		.EQU	1		; MD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
+MDFFENABLE	.EQU	FALSE		; MD: ENABLE FLASH FILE SYSTEM
+;
+FDENABLE	.EQU	FALSE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
+FDMODE		.EQU	FDMODE_ZETA2	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|ZETA2|DIDE|N8|DIO3|RCSMC|RCWDC|DYNO|EPFDC|MBC]
+FDCNT		.EQU	1		; FD: NUMBER OF FLOPPY DRIVES ON THE INTERFACE (1-2)
+FDTRACE		.EQU	1		; FD: TRACE LEVEL (0=NO,1=FATAL,2=ERRORS,3=ALL)
+FDMEDIA		.EQU	FDM144		; FD: DEFAULT MEDIA FORMAT FDM[720|144|360|120|111]
+FDMEDIAALT	.EQU	FDM720		; FD: ALTERNATE MEDIA FORMAT FDM[720|144|360|120|111]
+FDMAUTO		.EQU	TRUE		; FD: AUTO SELECT DEFAULT/ALTERNATE MEDIA FORMATS
+;
+RFENABLE	.EQU	FALSE		; RF: ENABLE RAM FLOPPY DRIVER
+;
+IDEENABLE	.EQU	FALSE		; IDE: ENABLE IDE DISK DRIVER (IDE.ASM)
+;
+PPIDEENABLE	.EQU	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
+PPIDETRACE	.EQU	1		; PPIDE: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
+PPIDECNT	.EQU	1		; PPIDE: NUMBER OF PPI CHIPS TO DETECT (1-3), 2 DRIVES PER CHIP
+PPIDE0BASE	.EQU	$60		; PPIDE 0: PPI REGISTERS BASE ADR
+PPIDE0A8BIT	.EQU	FALSE		; PPIDE 0A (MASTER): 8 BIT XFER
+PPIDE0B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
+;
+SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
+SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
+SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
+SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
+SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
+SDCSIOFAST	.EQU	FALSE		; SD: ENABLE TABLE-DRIVEN BIT INVERTER IN CSIO MODE
+;
+PRPENABLE	.EQU	FALSE		; PRP: ENABLE ECB PROPELLER IO BOARD DRIVER (PRP.ASM)
+;
+PPPENABLE	.EQU	FALSE		; PPP: ENABLE ZETA PARALLEL PORT PROPELLER BOARD DRIVER (PPP.ASM)
+PPPBASE		.EQU	$60		; PPP: PPI REGISTERS BASE ADDRESS
+PPPSDENABLE	.EQU	TRUE		; PPP: ENABLE PPP DRIVER SD CARD SUPPORT
+PPPSDTRACE	.EQU	1		; PPP: SD CARD TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
+PPPCONENABLE	.EQU	TRUE		; PPP: ENABLE PPP DRIVER VIDEO/KBD SUPPORT
+;
+HDSKENABLE	.EQU	FALSE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
+;
+PIOENABLE	.EQU	FALSE		; PIO: ENABLE ZILOG PIO DRIVER (PIO.ASM)
+;
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
+;
+PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
+PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
+PIO_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
+PIOSBASE	.EQU	$60		; PIO: PIO REGISTERS BASE ADR FOR SBC PPI
+;
+UFENABLE	.EQU	FALSE		; UF: ENABLE ECB USB FIFO DRIVER (UF.ASM)
+;
+SN76489ENABLE	.EQU	FALSE		; SN76489 SOUND DRIVER
+AY38910ENABLE	.EQU	FALSE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
+;
+DMAENABLE	.EQU	FALSE		; DMA: ENABLE DMA DRIVER (DMA.ASM)
+DMABASE		.EQU	$E0		; DMA: DMA BASE ADDRESS
+DMAMODE		.EQU	DMAMODE_NONE	; DMA: DMA MODE (NONE|ECB|Z180|Z280|RC|MBC)
+;
+YM2612ENABLE	.EQU	FALSE		; YM2612: ENABLE YM2612 DRIVER (MUTE STUB)
+VGMBASE		.EQU	$C0		; YM2612: BASE ADDRESS FOR VGM BOARD (YM2612/SN76469s/CTC)
diff --git a/Source/HBIOS/cfg_zeta.asm b/Source/HBIOS/cfg_zeta.asm
index b2b69b81..5346fba6 100644
--- a/Source/HBIOS/cfg_zeta.asm
+++ b/Source/HBIOS/cfg_zeta.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_ZETA	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_ZETA	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; BIOS_[WBW|UNA]: HARDWARE BIOS
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -155,7 +155,7 @@ PPIDE0A8BIT	.EQU	FALSE		; PPIDE 0A (MASTER): 8 BIT XFER
 PPIDE0B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/cfg_zeta2.asm b/Source/HBIOS/cfg_zeta2.asm
index 23c0cadf..c1c1b5cc 100644
--- a/Source/HBIOS/cfg_zeta2.asm
+++ b/Source/HBIOS/cfg_zeta2.asm
@@ -15,7 +15,7 @@
 ;
 #INCLUDE "hbios.inc"
 ;
-PLATFORM	.EQU	PLT_ZETA2	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH]
+PLATFORM	.EQU	PLT_ZETA2	; PLT_[SBC|ZETA|ZETA2|N8|MK4|UNA|RCZ80|RCZ180|EZZ80|SCZ180|DYNO|RCZ280|MBC|RPH|Z80RETRO]
 CPUFAM		.EQU	CPU_Z80		; CPU FAMILY: CPU_[Z80|Z180|Z280]
 BIOS		.EQU	BIOS_WBW	; HARDWARE BIOS: BIOS_[WBW|UNA]
 BATCOND		.EQU	FALSE		; ENABLE LOW BATTERY WARNING MESSAGE
@@ -166,7 +166,7 @@ PPIDE0A8BIT	.EQU	FALSE		; PPIDE 0A (MASTER): 8 BIT XFER
 PPIDE0B8BIT	.EQU	FALSE		; PPIDE 0B (SLAVE): 8 BIT XFER
 ;
 SDENABLE	.EQU	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
-SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|USR]
+SDMODE		.EQU	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|USR]
 SDPPIBASE	.EQU	$60		; SD: BASE I/O ADDRESS OF PPI FOR PPI MODDE
 SDCNT		.EQU	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD/SC/MT ONLY
 SDTRACE		.EQU	1		; SD: TRACE LEVEL (0=NO,1=ERRORS,2=ALL)
diff --git a/Source/HBIOS/hbios.inc b/Source/HBIOS/hbios.inc
index 35d83ff4..ba09f728 100644
--- a/Source/HBIOS/hbios.inc
+++ b/Source/HBIOS/hbios.inc
@@ -139,6 +139,7 @@ PLT_DYNO	.EQU	11		; DYNO MICRO-ATX MOTHERBOARD
 PLT_RCZ280	.EQU	12		; RCBUS W/ Z280
 PLT_MBC		.EQU	13		; MULTI BOARD COMPUTER
 PLT_RPH		.EQU	14		; RHYOPHYRE GRAPHICS COMPUTER
+PLT_Z80RETRO	.EQU	15		; Z80 RETRO COMPUTER
 ;
 ; HBIOS GLOBAL ERROR RETURN VALUES
 ;
@@ -265,9 +266,9 @@ DIAG_09 .EQU 11111111B ; ON
 ;
 ; FRONT PANEL SWITCHES
 ;
-SW_AUTO		.EQU	%10000000	; AUTO/MENU BOOT
-SW_CRT		.EQU	%01000000	; CRT/SER CONSOLE
-SW_SEC		.EQU	%00100000	; SEC/PRI CONSOLE
+SW_CRT		.EQU	%10000000	; CRT/SER CONSOLE
+SW_SEC		.EQU	%01000000	; SEC/PRI CONSOLE
+SW_AUTO		.EQU	%00100000	; AUTO/MENU BOOT
 SW_DISK		.EQU	%00010000	; DISK/ROM
 SW_FLOP		.EQU	%00001000	; FLOP/HD
 SW_OPT		.EQU	%00000111	; SLICE/ROM APP
diff --git a/Source/HBIOS/romldr.asm b/Source/HBIOS/romldr.asm
index ffcb676c..c350454a 100644
--- a/Source/HBIOS/romldr.asm
+++ b/Source/HBIOS/romldr.asm
@@ -453,12 +453,19 @@ fp_hdboot1:
 	pop	bc			; restore loop control
 	ld	a,d			; device type to A
 	cp	DIODEV_IDE		; type IDE or greater is HD
-	jr	nc,fp_hdboot2		; if hd, go boot it
+	jr	c,fp_hdboot2		; if not, continue loop
+	push	bc			; save loop control
+	ld	b,BF_DIOMEDIA		; HBIOS Sense Media
+	ld	e,1			; perform media discovery
+	rst	08			; do it
+	pop	bc			; restore loop control
+	jr	z,fp_hdboot3		; if has media, go boot it
+fp_hdboot2:
 	inc	c			; else next disk
 	djnz	fp_hdboot1		; loop thru all disks
 	ret				; nothing works, abort
 ;
-fp_hdboot2:
+fp_hdboot3:
 	ld	a,c			; disk unit to A
 	ld	(bootunit),a		; save it
 	ld	a,(switches)		; get switches value
diff --git a/Source/HBIOS/sd.asm b/Source/HBIOS/sd.asm
index 57440e13..f3e373be 100644
--- a/Source/HBIOS/sd.asm
+++ b/Source/HBIOS/sd.asm
@@ -282,6 +282,35 @@ SD_INVCS	.EQU	FALSE		; INVERT CS
 #ENDIF
 ;
 ;
+#IF (SDMODE == SDMODE_PIO)		; Z80 PIO
+;
+;	These mappings work for the RCbus Gluino card with an Arduino
+;	shield attached and are the ones also used in other bitbang setups
+;	directly attached to a PIO. It also works on a straight digital I/O
+;	port as the config writes will disappear into oblivion harmlessly
+;	
+;	The Gluino mapping (ie Arduino pin mapping equivalent) is thus
+;	D10 SS, D11 CIPO, D12 COPI, D13 SCL.
+;
+;	For speed reasons MISO/MOSI are mapped to the top and bottom bits.
+;	RomWBW doesn't yet use this fact but the optimized Fuzix routines do.
+;
+SD_DEVMAX	.EQU	1		; NUMBER OF PHYSICAL UNITS (SOCKETS)
+SD_IOBASE	.EQU	$69		; IO BASE ADDRESS FOR SD INTERFACE
+SD_OPRREG	.EQU	SD_IOBASE	; OUTPUT PORT (OUTPUT: CS, CLK, DIN)
+SD_OPRDEF	.EQU	%11111111	; OUTPUT PORT DEFAULT STATE
+SD_INPREG	.EQU	SD_IOBASE	; INPUT REGISTER
+SD_CS0		.EQU	%00001000	; SELECT
+SD_CLK		.EQU	%00010000	; CLOCK
+SD_DI		.EQU	%00000001	; DATA IN (CARD <- CPU) MOSI
+SD_DO		.EQU	%10000000	; DATA OUT (CARD -> CPU) MISO
+SD_CINIT	.EQU	TRUE		; INITIALIZE OUTPUT PORT
+SD_DDR		.EQU	$6B		; DATA DIRECTION REGISTER
+SD_DDRVAL	.EQU	%11100110	; DATA DIRECTION REGISTER VALUE
+SD_INVCS	.EQU	TRUE		; INVERT CS
+#ENDIF
+;
+;
 #IF (SDMODE == SDMODE_USR)		; USER DEFINED HARDWARE CONFIGURATION
 ;
 ; THIS MODE IS INTENDED TO ALLOW A USER TO EASILY CONFIGURE A CUSTOM
@@ -510,6 +539,13 @@ SD_INIT:
 	CALL	PRTHEXBYTE
 #ENDIF
 ;
+#IF (SDMODE == SDMODE_PIO)
+	PRTS(" MODE=PIO$")
+	PRTS(" IO=0x$")
+	LD	A,SD_IOBASE
+	CALL	PRTHEXBYTE
+#ENDIF
+;
 #IF (SDMODE == SDMODE_USR)
 	PRTS(" MODE=USER$")
 	PRTS(" IO=0x$")
@@ -1736,6 +1772,17 @@ SD_SETUP:
 	OUT	(SD_OPRREG),A		; OPRREG == SIO_MCR
 #ENDIF
 ;
+#IF (SDMODE == SDMODE_PIO)
+	LD	A,SD_OPRDEF		; All output bits high
+	OUT	(SD_OPRREG),A
+	LD	A,$CF			; Port B mode 3
+	OUT	(SD_DDR),A
+	LD	A,SD_DDRVAL		; Set the direction bits
+	OUT	(SD_DDR),A
+	LD	A,$07			; No interrupts
+	OUT	(SD_DDR),A
+#ENDIF
+;
 #IF (SDMODE == SDMODE_USR)
   #IF (SD_CINIT == TRUE)
 	LD	A,(SD_OPRMSK)		; GET OUTPUT PORT MASK
@@ -1863,7 +1910,7 @@ SD_DESELECT:
 	AND	~SD_CS0
 #ENDIF
 ; ADJUST BIT(S) FOR INTERFACES USING INVERTED CS BITS
-#IF ((SDMODE == SDMODE_PPI) | (SDMODE == SDMODE_UART) | (SDMODE == SDMODE_SC))
+#IF ((SDMODE == SDMODE_PPI) | (SDMODE == SDMODE_UART) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_PIO))
   #IF ((SDMODE == SDMODE_SC) & (SD_DEVCNT > 1))
 	XOR	SD_CS0 | SD_CS1
   #ELSE
@@ -1956,7 +2003,7 @@ SD_GET1:
 	XOR	SD_CLK			; TOGGLE CLOCK
 	OUT	(SD_OPRREG),A		; UPDATE CLOCK
 	IN	A,(SD_INPREG)		; READ THE DATA WHILE CLOCK IS ACTIVE
-    #IF ((SDMODE == SDMODE_JUHA) | (SDMODE == SDMODE_PPI))
+    #IF ((SDMODE == SDMODE_JUHA) | (SDMODE == SDMODE_PPI) | (SDMODE == SDMODE_PIO))
 	RLA				; ROTATE INP:7 INTO CF
     #ENDIF
     #IF (SDMODE == SDMODE_N8)
diff --git a/Source/HBIOS/sio.asm b/Source/HBIOS/sio.asm
index ef707680..2a101d48 100644
--- a/Source/HBIOS/sio.asm
+++ b/Source/HBIOS/sio.asm
@@ -60,13 +60,20 @@ SIO0B_CMD	.EQU	SIO0BASE + $03
 SIO0B_DAT	.EQU	SIO0BASE + $01
 #ENDIF
 ;
-#IF (SIO0MODE == SIOMODE_ZP)		
+#IF (SIO0MODE == SIOMODE_ZP)
 SIO0A_CMD	.EQU	SIO0BASE + $06
 SIO0A_DAT	.EQU	SIO0BASE + $04 
 SIO0B_CMD	.EQU	SIO0BASE + $07
 SIO0B_DAT	.EQU	SIO0BASE + $05
 #ENDIF
 ;
+#IF (SIO0MODE == SIOMODE_Z80R)
+SIO0A_CMD	.EQU	SIO0BASE + $03
+SIO0A_DAT	.EQU	SIO0BASE + $02 
+SIO0B_CMD	.EQU	SIO0BASE + $01
+SIO0B_DAT	.EQU	SIO0BASE + $00
+#ENDIF
+;
 #IF (SIOCNT >= 2)
 ;
   #IF (SIO1MODE == SIOMODE_STD)
@@ -97,6 +104,13 @@ SIO1B_CMD	.EQU	SIO1BASE + $07
 SIO1B_DAT	.EQU	SIO1BASE + $05
   #ENDIF
 ;
+#IF (SIO1MODE == SIOMODE_Z80R)
+SIO1A_CMD	.EQU	SIO0BASE + $03
+SIO1A_DAT	.EQU	SIO0BASE + $02 
+SIO1B_CMD	.EQU	SIO0BASE + $01
+SIO1B_DAT	.EQU	SIO0BASE + $00
+#ENDIF
+;
 #ENDIF
 ;
 SIO_PREINIT:
diff --git a/Source/HBIOS/std.asm b/Source/HBIOS/std.asm
index a4d3729e..4734b6ce 100644
--- a/Source/HBIOS/std.asm
+++ b/Source/HBIOS/std.asm
@@ -1,5 +1,5 @@
 ; The purpose of this file is to define generic symbols and to include
-; the requested build configuraton file to bring in platform specifics.
+; the requested build configuration file to bring in platform specifics.
 
 ; There are several hardware platforms supported by SBC.
 ; 1.  SBC	Z80 SBC (v1 or v2) w/ ECB interface
@@ -16,6 +16,7 @@
 ; 12. RCZ280	Z280 CPU on RCBUS or ZZ80MB
 ; 13. MBC	Andrew Lynch's Multi Board Computer
 ; 14. RPH	Andrew Lynch's RHYOPHYRE Graphics Computer
+; 15. Z80RETRO	Peter Wilson's Z80-Retro Computer
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;
@@ -116,6 +117,7 @@ SIOMODE_STD	.EQU	1		; STD SIO REG CFG (EZZ80, KIO)
 SIOMODE_RC	.EQU	2		; RCBUS SIO MODULE (SPENCER OWEN)
 SIOMODE_SMB	.EQU	3		; RCBUS SIO MODULE (SCOTT BAKER)
 SIOMODE_ZP	.EQU	4		; ECB-ZILOG PERIPHERALS BOARD
+SIOMODE_Z80R	.EQU	5		; SIO A/B SWAPPED
 ;
 ; TYPE OF CONSOLE BELL TO USE
 ;
@@ -182,6 +184,7 @@ SDMODE_MK4	.EQU	7		; MARK IV
 SDMODE_SC	.EQU	8		; SC (Steve Cousins)
 SDMODE_MT	.EQU	9		; MT (Shift register SPI WIZNET for RCBUS)
 SDMODE_USR	.EQU	10		; USER DEFINED (in sd.asm) (NOT COMPLETE)
+SDMODE_PIO	.EQU	11		; Z80 PIO bitbang
 ;
 ; AY SOUND CHIP MODE SELECTIONS
 ;
diff --git a/Source/ver.inc b/Source/ver.inc
index 136b86bb..89186f9b 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.0"
+#DEFINE BIOSVER	"3.3.0-dev.1"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
diff --git a/Source/ver.lib b/Source/ver.lib
index 04db95f2..1d3826c0 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.0"
+	db	"3.3.0-dev.1"
 	endm