diff --git a/Binary/ReadMe.txt b/Binary/ReadMe.txt
index 6118199f..0021d0d3 100644
--- a/Binary/ReadMe.txt
+++ b/Binary/ReadMe.txt
@@ -75,8 +75,8 @@ The VDU video board requires a dedicated onboard ROM containing the
 font data.  The "vdu.rom" file contains the binary data to program 
 onto that chip.
 
-Disk Images (fd_*.img, hd_*.img)
-------------------------------
+Disk Images (fd_*.img, hd_*.img, psys.img)
+------------------------------------------
 
 RomWBW includes a mechanism for generating floppy disk and hard disk 
 binary images that are ready to copy directly to a floppy, hard disk, 
@@ -96,16 +96,18 @@ RawWriteWin (as long as you have access to a floppy drive on your
 Windows computer).  The resulting floppy disks will be usable on any 
 RomWBW-based system with floppy drive(s).
 
-Likewise, the hd_*.img files are hard disk images.  Each file is 
-intended to be copied to the start of any type of hard disk media 
-(typically a CF Card or SD Card). The resulting media will be usable 
-on any RomWBW-based system that accepts the corresponding media type.
+Likewise, the hd512_*.img and hd1024_*.img files are hard disk images.  
+Each file is intended to be copied to the start of any type of hard 
+disk media (typically a CF Card or SD Card). The resulting media will 
+be usable on any RomWBW-based system that accepts the corresponding 
+media type.
 
-WARNING: The hdnew_*.img disk images are part of a new disk
-format that is a work in progress.  Do not use these disk
-images without knowing exactly what you are doing!  The
-hd_*.img disk images continue to be the images you should
-be using under normal circumstances.
+NOTE: The hd512_*.img files are equivalent to the hd_*.img
+files in previous distributions.  The hd1024_*.img files
+contained a revised file system format that increases the
+maximum number of CP/M directory entries from 512 to 1024.
+Refer to the ReadMe.txt in the Source/Images directory
+for details.
 
 Documentation of the pre-built disk images is contained in the 
 DiskList.txt file in this directory.
@@ -115,6 +117,12 @@ the BuildImages.cmd script in the Source directory.  Additional
 information on how to generate custom disk images is found in the 
 Source\Images ReadMe.txt file.
 
+The psys.img file contains a full implementation of the UCSD p-System 
+for the Z80 running under RomWBW.  This image file must be placed on 
+disk media by itself (not appended or concatenated with hd*.img files.  
+Refer to the Source/pSys/ReadMe.txt file for more information on the 
+p-System implementation.
+
 Propeller ROM Images (*.eeprom)
 -------------------------------
 
diff --git a/Doc/ChangeLog.txt b/Doc/ChangeLog.txt
index f3fc30d2..44d037c0 100644
--- a/Doc/ChangeLog.txt
+++ b/Doc/ChangeLog.txt
@@ -67,6 +67,7 @@ Version 3.1.1
 - LLS: Added a user defined mode for SD Card interfaces (not complete)
 - L?N: Updated ZDE to v1.8 including time stamp preservation fixes
 - D?M: Minor update to CP/NET client files, fix to CPNBOOT
+- WBW: Added p-System IV.0 Z80 implementation
 
 Version 3.1
 -----------
diff --git a/Doc/ROM Applications.pdf b/Doc/ROM Applications.pdf
index 77dbe27a..cfd947b6 100644
Binary files a/Doc/ROM Applications.pdf and b/Doc/ROM Applications.pdf differ
diff --git a/Doc/RomWBW Applications.pdf b/Doc/RomWBW Applications.pdf
index 4c4f3a13..370de57c 100644
Binary files a/Doc/RomWBW Applications.pdf and b/Doc/RomWBW Applications.pdf differ
diff --git a/Doc/RomWBW Architecture.pdf b/Doc/RomWBW Architecture.pdf
index b1f981df..6fb56ef5 100644
Binary files a/Doc/RomWBW Architecture.pdf and b/Doc/RomWBW Architecture.pdf differ
diff --git a/Doc/RomWBW Disk Catalog.pdf b/Doc/RomWBW Disk Catalog.pdf
index ce658358..e1e9ad78 100644
Binary files a/Doc/RomWBW Disk Catalog.pdf and b/Doc/RomWBW Disk Catalog.pdf differ
diff --git a/Doc/RomWBW Getting Started.pdf b/Doc/RomWBW Getting Started.pdf
index 29f558e3..5e4bee5f 100644
Binary files a/Doc/RomWBW Getting Started.pdf and b/Doc/RomWBW Getting Started.pdf differ
diff --git a/Doc/UCSD p-System Users Manual.pdf b/Doc/UCSD p-System Users Manual.pdf
new file mode 100644
index 00000000..5affaf78
Binary files /dev/null and b/Doc/UCSD p-System Users Manual.pdf differ
diff --git a/Doc/qcp27.pdf b/Doc/qcp27.pdf
new file mode 100644
index 00000000..56f4996b
Binary files /dev/null and b/Doc/qcp27.pdf differ
diff --git a/Doc/qdos27.pdf b/Doc/qdos27.pdf
new file mode 100644
index 00000000..10723a0c
Binary files /dev/null and b/Doc/qdos27.pdf differ
diff --git a/Doc/qpm27.pdf b/Doc/qpm27.pdf
new file mode 100644
index 00000000..116b5c66
Binary files /dev/null and b/Doc/qpm27.pdf differ
diff --git a/ReadMe.md b/ReadMe.md
index da55ac1c..6988a610 100644
--- a/ReadMe.md
+++ b/ReadMe.md
@@ -3,7 +3,7 @@
 ## Z80/Z180 System Software
 
 Version 3.1 Pre-release  
-01 Jan 2023
+13 Jan 2023
 
 Wayne Warthen <wwarthen@gmail.com>
 
@@ -664,6 +664,11 @@ boot from disk as is. You do not need to run `SYSCOPY` on them to make
 them bootable. However, if you upgrade your ROM, you should use
 `SYSCOPY` to update the system tracks.
 
+A full implementation of the UCSD p-System for Z80 under RomWBW is also
+provided. This is a completely separate and standalone disk image called
+psys.img. It contains 6 p-System filesystem slices, but these are not
+interoperable with the CP/M slices described above.
+
 ## Booting Disks
 
 When starting your system, following the hardware initialization, you
@@ -845,6 +850,69 @@ tracks of the disk.
   I believe it was done this way to make it easier for users to
   transition from CP/M 3 to ZPM3.
 
+## QPM
+
+QPM is another OS providing compatibility with and enhancements to CP/M
+2.2. It is provided as bootable disk images for RomWBW.
+
+The following documentation files from the original QPM distribution are
+included in the RomWBW Doc directory:
+
+- QP/M 2.7 Features and Facilities (qcp27.pdf)
+- QP/M 2.7 Interface Guide (qdos27.pdf)
+- QP/M 2.7 Installation Guide and Supplements (qpm27.pdf)
+
+Refer to the ReadMe.txt file in Source/Images/d_qpm for more details
+regarding the RomWBW adaptation and customizations.
+
+### Notes
+
+- QPM is not available as source. This implementation was based on the
+  QPM binary distribution and has been minimally customized for RomWBW.
+
+- QINSTALL is used to customize QPM. It is included on the disk image.
+  You should review the notes in the ReadMe.txt file in
+  Source/Image/d_qpm before making changes.
+
+## UCSD p-System
+
+This is a full implementation of the UCSD p-System IV.0 for Z80 running
+under RomWBW. Unlike the OSes above, p-System uses it’s own unique
+filesystem and is not interoperable with other OSes.
+
+It was derived from the p-System Adaptable Z80 System. Unlike some other
+distributions, this implements a native p-System Z80 BIOS, it does not
+rely on a CP/M BIOS layer.
+
+The p-System is provided on a hard disk image file called psys.img. This
+must be copied to it’s own dedicated hard disk media (CF Card, SD Card,
+etc.). It is booted by selecting slices 0 of the corresponding hard disk
+unit at the RomWBW Boot Loader prompt.
+
+The p-System Users Manual is included in the Doc directory of the
+distribution as “UCSD p-System Users Manual.pdf”.
+
+Refer to the ReadMe.txt file in Source/pSys for more details.
+
+### Notes
+
+- There is no floppy support at this time.
+
+- The hard disk image contains 6 p-System slices which are assigned to
+  p-System unit numbers 4, 5, 9, 10, 11 which is standard for p-System.
+  Slices 0-5 are assigned sequentially to these p-System unit numbers
+  and it is not possible to reassign them.
+
+- p-System relies heavily on the use of a full screen terminal. This
+  implementation has been setup to expect an ANSI or DEC VT-100 terminal
+  or emulator. The screen output will be garbled if no such terminal or
+  emulator is used for console output.
+
+- There is no straightforward mechanism to move files in and out of
+  p-System. However, the .vol files in Source/pSys can be read and
+  modified by CiderPress. CiderPress is able to add and remove
+  individual files.
+
 ## FreeRTOS
 
 Phillip Stevens has ported FreeRTOS to run under RomWBW. FreeRTOS is not
diff --git a/ReadMe.txt b/ReadMe.txt
index 6a7c7c8b..d1ed1570 100644
--- a/ReadMe.txt
+++ b/ReadMe.txt
@@ -1,6 +1,6 @@
 RomWBW Getting Started
 Wayne Warthen (mailto:wwarthen@gmail.com)
-01 Jan 2023
+13 Jan 2023
 
 
 
@@ -17,7 +17,7 @@ RomWBW
 Z80/Z180 System Software
 
 Version 3.1 Pre-release
-01 Jan 2023
+13 Jan 2023
 
 Wayne Warthen wwarthen@gmail.com
 
@@ -736,6 +736,11 @@ boot from disk as is. You do not need to run SYSCOPY on them to make
 them bootable. However, if you upgrade your ROM, you should use SYSCOPY
 to update the system tracks.
 
+A full implementation of the UCSD p-System for Z80 under RomWBW is also
+provided. This is a completely separate and standalone disk image called
+psys.img. It contains 6 p-System filesystem slices, but these are not
+interoperable with the CP/M slices described above.
+
 Booting Disks
 
 When starting your system, following the hardware initialization, you
@@ -916,6 +921,70 @@ Notes
     distribution. I believe it was done this way to make it easier for
     users to transition from CP/M 3 to ZPM3.
 
+QPM
+
+QPM is another OS providing compatibility with and enhancements to CP/M
+2.2. It is provided as bootable disk images for RomWBW.
+
+The following documentation files from the original QPM distribution are
+included in the RomWBW Doc directory:
+
+-   QP/M 2.7 Features and Facilities (qcp27.pdf)
+-   QP/M 2.7 Interface Guide (qdos27.pdf)
+-   QP/M 2.7 Installation Guide and Supplements (qpm27.pdf)
+
+Refer to the ReadMe.txt file in Source/Images/d_qpm for more details
+regarding the RomWBW adaptation and customizations.
+
+Notes
+
+-   QPM is not available as source. This implementation was based on the
+    QPM binary distribution and has been minimally customized for
+    RomWBW.
+
+-   QINSTALL is used to customize QPM. It is included on the disk image.
+    You should review the notes in the ReadMe.txt file in
+    Source/Image/d_qpm before making changes.
+
+UCSD p-System
+
+This is a full implementation of the UCSD p-System IV.0 for Z80 running
+under RomWBW. Unlike the OSes above, p-System uses it’s own unique
+filesystem and is not interoperable with other OSes.
+
+It was derived from the p-System Adaptable Z80 System. Unlike some other
+distributions, this implements a native p-System Z80 BIOS, it does not
+rely on a CP/M BIOS layer.
+
+The p-System is provided on a hard disk image file called psys.img. This
+must be copied to it’s own dedicated hard disk media (CF Card, SD Card,
+etc.). It is booted by selecting slices 0 of the corresponding hard disk
+unit at the RomWBW Boot Loader prompt.
+
+The p-System Users Manual is included in the Doc directory of the
+distribution as “UCSD p-System Users Manual.pdf”.
+
+Refer to the ReadMe.txt file in Source/pSys for more details.
+
+Notes
+
+-   There is no floppy support at this time.
+
+-   The hard disk image contains 6 p-System slices which are assigned to
+    p-System unit numbers 4, 5, 9, 10, 11 which is standard for
+    p-System. Slices 0-5 are assigned sequentially to these p-System
+    unit numbers and it is not possible to reassign them.
+
+-   p-System relies heavily on the use of a full screen terminal. This
+    implementation has been setup to expect an ANSI or DEC VT-100
+    terminal or emulator. The screen output will be garbled if no such
+    terminal or emulator is used for console output.
+
+-   There is no straightforward mechanism to move files in and out of
+    p-System. However, the .vol files in Source/pSys can be read and
+    modified by CiderPress. CiderPress is able to add and remove
+    individual files.
+
 FreeRTOS
 
 Phillip Stevens has ported FreeRTOS to run under RomWBW. FreeRTOS is not
diff --git a/Source/BuildShared.cmd b/Source/BuildShared.cmd
index ea9a7b10..8b7e0442 100644
--- a/Source/BuildShared.cmd
+++ b/Source/BuildShared.cmd
@@ -9,6 +9,7 @@ pushd ZCPR-DJ && call Build || exit /b & popd
 pushd ZSDOS && call Build || exit /b & popd
 pushd CPM3 && call Build || exit /b & popd
 pushd ZPM3 && call Build || exit /b & popd
+pushd pSys && call Build || exit /b & popd
 pushd Apps && call Build || exit /b & popd
 pushd Forth && call Build || exit /b & popd
 pushd TastyBasic && call Build || exit /b & popd
diff --git a/Source/Clean.cmd b/Source/Clean.cmd
index 1af0deff..d3b69d40 100644
--- a/Source/Clean.cmd
+++ b/Source/Clean.cmd
@@ -10,6 +10,7 @@ pushd ZSDOS && call Clean.cmd & popd
 pushd CBIOS && call Clean.cmd & popd
 pushd CPM3 && call Clean.cmd & popd
 pushd ZPM3 && call Clean.cmd & popd
+pushd pSys && call Clean.cmd & popd
 pushd Forth && call Clean.cmd & popd
 pushd TastyBasic && call Clean & popd
 pushd Fonts && call Clean.cmd & popd
diff --git a/Source/Doc/GettingStarted.md b/Source/Doc/GettingStarted.md
index 9554e4c8..d492f315 100644
--- a/Source/Doc/GettingStarted.md
+++ b/Source/Doc/GettingStarted.md
@@ -684,6 +684,11 @@ boot from disk as is. You do not need to run `SYSCOPY` on them to make
 them bootable. However, if you upgrade your ROM, you should use `SYSCOPY`
 to update the system tracks.
 
+A full implementation of the UCSD p-System for Z80 under RomWBW is also
+provided.  This is a completely separate and standalone disk image
+called psys.img.  It contains 6 p-System filesystem slices, but these
+are not interoperable with the CP/M slices described above.
+
 ## Booting Disks
 
 When starting your system, following the hardware initialization, you
@@ -869,6 +874,73 @@ which is confusing, but this is as intended by the ZPM3 distribution.
 I believe it was done this way to make it easier for users to transition
 from CP/M 3 to ZPM3.
 
+## QPM
+
+QPM is another OS providing compatibility with and enhancements
+to CP/M 2.2.  It is provided as bootable disk images for RomWBW.
+
+The following documentation files from the original QPM distribution
+are included in the RomWBW Doc directory:
+
+ - QP/M 2.7 Features and Facilities (qcp27.pdf)
+ - QP/M 2.7 Interface Guide (qdos27.pdf)
+ - QP/M 2.7 Installation Guide and Supplements (qpm27.pdf)
+
+Refer to the ReadMe.txt file in Source/Images/d_qpm for more details
+regarding the RomWBW adaptation and customizations.
+
+### Notes
+
+- QPM is not available as source.  This implementation was based
+on the QPM binary distribution and has been minimally customized
+for RomWBW.
+
+- QINSTALL is used to customize QPM.  It is included on the
+disk image.  You should review the notes in the ReadMe.txt
+file in Source/Image/d_qpm before making changes.
+
+## UCSD p-System
+
+This is a full implementation of the UCSD p-System IV.0 for Z80
+running under RomWBW.  Unlike the OSes above, p-System uses it's
+own unique filesystem and is not interoperable with other OSes.
+
+It was derived from the p-System Adaptable Z80 System.  Unlike
+some other distributions, this implements a native p-System
+Z80 BIOS, it does not rely on a CP/M BIOS layer.
+
+The p-System is provided on a hard disk image file called
+psys.img.  This must be copied to it's own dedicated hard
+disk media (CF Card, SD Card, etc.).  It is booted by
+selecting slices 0 of the corresponding hard disk unit at
+the RomWBW Boot Loader prompt.
+
+The p-System Users Manual is included in the Doc directory
+of the distribution as "UCSD p-System Users Manual.pdf".
+
+Refer to the ReadMe.txt file in Source/pSys for more details.
+
+### Notes
+
+- There is no floppy support at this time.
+
+- The hard disk image contains 6 p-System slices which are
+assigned to p-System unit numbers 4, 5, 9, 10, 11 which
+is standard for p-System.  Slices 0-5 are assigned
+sequentially to these p-System unit numbers and it is
+not possible to reassign them.
+
+- p-System relies heavily on the use of a full screen
+terminal.  This implementation has been setup to expect
+an ANSI or DEC VT-100 terminal or emulator.  The screen
+output will be garbled if no such terminal or emulator
+is used for console output.
+
+- There is no straightforward mechanism to move files in
+and out of p-System.  However, the .vol files in Source/pSys
+can be read and modified by CiderPress.  CiderPress is able
+to add and remove individual files.
+
 ## FreeRTOS
 
 Phillip Stevens has ported FreeRTOS to run under RomWBW. FreeRTOS is
diff --git a/Source/Makefile b/Source/Makefile
index d0dc7de1..b012323f 100644
--- a/Source/Makefile
+++ b/Source/Makefile
@@ -10,6 +10,7 @@ SUBDIRS += TastyBasic
 SUBDIRS += Fonts
 SUBDIRS += CPM22 ZCPR ZCPR-DJ ZSDOS CPM3 ZPM3
 #SUBDIRS += BPBIOS
+SUBDIRS += pSys
 SUBDIRS += RomDsk
 SUBDIRS += HBIOS
 SUBDIRS += Images
diff --git a/Source/pSys/Build.cmd b/Source/pSys/Build.cmd
new file mode 100644
index 00000000..f0c914c6
--- /dev/null
+++ b/Source/pSys/Build.cmd
@@ -0,0 +1,37 @@
+@echo off
+setlocal
+
+set TOOLS=../../Tools
+
+set PATH=%TOOLS%\tasm32;%PATH%
+
+set TASMTABS=%TOOLS%\tasm32
+
+echo.
+echo Building p-System Loader for RomWBW...
+echo.
+tasm -t80 -g3 loader.asm loader.bin loader.lst || exit /b
+if errorlevel 1 goto :eof
+
+echo.
+echo Building p-System BIOS for RomWBW...
+echo.
+tasm -t80 -g3 bios.asm bios.bin bios.lst || exit /b
+if errorlevel 1 goto :eof
+
+::echo.
+::echo Creating p-System BIOS Tester boot image
+::echo.
+::copy /b loader.bin + bios.bin + biostest.dat psys.bin
+
+echo.
+echo Generating p-System Boot Track...
+echo.
+copy /b loader.bin + bios.bin + boot.dat + fill.dat trk0.bin  || exit /b
+
+echo.
+echo Generating p-System Disk Image...
+echo.
+copy /b trk0.bin + psys.vol + trk0.bin + blank.vol psys.img || exit /b
+
+copy psys.img ..\..\Binary  || exit /b
\ No newline at end of file
diff --git a/Source/pSys/Clean.cmd b/Source/pSys/Clean.cmd
new file mode 100644
index 00000000..f9ed83d2
--- /dev/null
+++ b/Source/pSys/Clean.cmd
@@ -0,0 +1,6 @@
+@echo off
+setlocal
+
+if exist *.bin del *.bin
+if exist *.lst del *.lst
+if exist *.img del *.img
diff --git a/Source/pSys/Makefile b/Source/pSys/Makefile
new file mode 100644
index 00000000..427470af
--- /dev/null
+++ b/Source/pSys/Makefile
@@ -0,0 +1,11 @@
+OBJECTS = psys.img
+TOOLS = ../../Tools
+DEST = ../../Binary
+OTHERS = *.bin *.lst *.img
+include $(TOOLS)/Makefile.inc
+
+trk0.bin: loader.bin bios.bin boot.dat fill.dat
+	cat loader.bin bios.bin boot.dat fill.dat > trk0.bin
+
+psys.img: trk0.bin psys.vol blank.vol
+	cat trk0.bin psys.vol trk0.bin blank.vol > psys.img
diff --git a/Source/pSys/ReadMe.txt b/Source/pSys/ReadMe.txt
new file mode 100644
index 00000000..04d335a0
--- /dev/null
+++ b/Source/pSys/ReadMe.txt
@@ -0,0 +1,100 @@
+This directory contains a port of p-System IV.0 for RomWBW.
+
+It was derived from the p-System Adaptable Z80 System.  Unlike
+some other distributions, this implements a native p-System
+Z80 BIOS, it does not use a CP/M BIOS layer.
+
+Files:
+
+loader.asm     p-System primary loader for RomWBW
+bios.asm       p-System BIOS for RomWBW HBIOS source (TASM)
+biostest.dat   binary image of SBIOSTESTER
+boot.dat       binary image of p-System bootstrap
+psys.vol       first (boot) slice, all p-System dist files
+blank.vol      a generic blank p-System volume
+fill.dat       used to complete the track 0 build (see below)
+
+Notes:
+
+This adatation runs on a single RomWBWW HBIOS hard disk
+type device (CF Cart, SD Card, IDE drive, etc.).  The
+image built (psys.img) should be copied to your disk media
+start at the first sector.  You can then boot by selecting
+the corresponding disk device unit number from the RomWBW
+boot loader prompt.  The p-System disk image (psys.img) is
+entirely different from the RomWBW CP/M-style disk images.
+
+The boot device hard disk is broken up into 6 logical
+p-System volumes.  These are referred to as p-System
+slices.  A single RomWBW disk device can contain either
+CP/M-style slices or p-System slices, but not both.
+Each p-System slices is exactly 8 MB and support for
+exactly 6 slices is provided.
+
+The first track of each volume contains all of the code
+required to boot the p-System.  However, the assignment
+of the volumes is always in the order that the slices
+appear physically on the hard disk device.  Normally,
+you would just boot to slice 0 from the RomWBW Boot
+Loader.
+
+The first track contains the following:
+ - 4 sector p-System primary loader for RomWBW HBIOS
+ - 1 sector p-System BIOS for RomWBW HBIOS
+ - 4 sector p-System bootstrap
+ - 7 sector filler to complete a full track
+
+The p-System bootstrap is a binary image provided in the
+p-System distribution.  The loader and the BIOS are
+custom for RomWBW and the source is provided here.
+
+The layout of the first track does not conform exactly to
+the recommended p-System layout.  The recommended layout
+is not possible because it conflicts with the RomWBW
+definition for a boot track.  However, the changes are
+simply slilghtly different sector assignments for the
+different boot componets -- the general boot sequence
+and mechanism for the p-System is completely standard.
+
+The logical disk geometry used by this p-System
+adaptation is:
+ - 512 byte sector length
+ - 16 sectors per track
+ - 192 tracks per disk
+
+This layout does not occupy the full 8MB slice size
+allocated.  This is to allow for future expansion of
+the filesystems.
+
+The p-System distribution includes a BIOS tester that
+is provided as a binary image.  This tester was used
+to test the BIOS code in this adaptation.  Note that
+the tester fails for the BIOS as is.  After a lot of
+code tracing, a definite bug was identified in the
+tester that exists for 512 byte sectors (which are
+supported).  When the BIOS is modified to use 128 or
+256 byte sectors, the tester completes perfectly.
+Significant use of the BIOS shows there are no issues
+for a normal running system with 512 byte sectors.
+
+The boot disk provided here was constructed by simply
+copying all of the content from the p-System distribution
+disks onto the boot disk.  SYSTEM.MISCINFO was updated
+for an ANSI terminal.  The GOTOXY routine in
+SYSTEM.PASCAL was also updated for an ANSI terminal.
+Note that the BIOS conwrit routine is hacked to add
+a '[' to any output escape character.  This is needed
+because p-System has limited terminal escape sequence
+handling configuration.
+
+At this time, there is no straightforward way to move
+files in and out of the p-System volumes.  There are
+ways to do this, but they are complicated.  Please
+contact me if you are interested.
+
+There is currently no support for floppy drives.
+
+Wayne Warthen
+wwarthen@gmail.com
+
+3:13 PM Thursday, January 12, 2023
\ No newline at end of file
diff --git a/Source/pSys/bios.asm b/Source/pSys/bios.asm
new file mode 100644
index 00000000..f7107b69
--- /dev/null
+++ b/Source/pSys/bios.asm
@@ -0,0 +1,371 @@
+;
+;-----------------------------------------------------------------------
+;   p-System BIOS for RomWBW HBIOS
+;
+;-----------------------------------------------------------------------
+;
+; 3:46 PM 1/13/2023 - WBW - Initial release
+;
+; TODO:
+;
+; - Assign the HBIOS console device to the p-System console instead
+;   of just using a hard-coded reference to Serial Unit 0.
+;
+; - Implement Extended BIOS.
+;
+
+#include "../ver.inc"
+;
+#include "psys.inc"
+;
+#include "../HBIOS/hbios.inc"
+;
+; IORESULT values
+;
+ior_ok		.equ	0		; No error
+ior_badblk	.equ	1		; Bad block, CRC error (parity)
+ior_baddev	.equ	2		; Bad device number
+ior_badio	.equ	3		; Illegal I/O request
+ior_timout	.equ	4		; Data-com timeout
+ior_offlin	.equ	5		; Volume is no longer on-line
+ior_nofile	.equ	6		; File is no longer in directory
+ior_filnamerr	.equ	7		; Illegal file name
+ior_full	.equ	8		; No room; insufficient space on disk
+ior_novol	.equ	9		; No such volume on-line
+ior_notfnd	.equ	10		; No such file name in directory
+ior_dupfil	.equ	11		; Duplicate file
+ior_notclos	.equ	12		; Not closed: attempt to open an open file
+ior_notopen	.equ	13		; Not open: attempt to access a closed file
+ior_badfmt	.equ	14		; Bad format: error reading real or integer
+ior_bufovr	.equ	15		; Ring buffer overflow
+ior_diskwp	.equ	16		; Write attempt to protected disk
+ior_blknumerr	.equ	17		; Illegal block number
+ior_bufadrerr	.equ	18		; Illegal buffer address
+ior_badsiz	.equ	19		; Bad text file size
+;
+;
+;
+	.org	bios_loc
+;
+	; Simple BIOS vectors
+	jp	sysinit		; 0: Initialize machine
+	jp	syshalt		; 1: Exit UCSD Pascal
+	jp	coninit		; 2: Console initialize
+	jp	constat		; 3: Console status
+	jp	conread		; 4: Console input
+	jp	conwrit		; 5: Console output
+	jp	setdisk		; 6: Set disk number
+	jp	settrak		; 7: Set track number
+	jp	setsect		; 8: Set sector number
+	jp	setbufr		; 9: Set buffer address
+	jp	dskread		; 10: Read sector from disk
+	jp	dskwrit		; 11: Write sector to disk
+	jp	dskinit		; 12: Reset disk
+	jp	dskstrt		; 13: Activate disk
+	jp	dskstop		; 14: De-activate disk
+;
+	; Extended BIOS vectors
+	jp	panic		; 15: Extended BIOS vector
+	jp	panic		; 16: Extended BIOS vector
+	jp	panic		; 17: Extended BIOS vector
+	jp	panic		; 18: Extended BIOS vector
+	jp	panic		; 19: Extended BIOS vector
+	jp	panic		; 20: Extended BIOS vector
+	jp	panic		; 21: Extended BIOS vector
+	jp	panic		; 22: Extended BIOS vector
+	jp	panic		; 23: Extended BIOS vector
+	jp	panic		; 24: Extended BIOS vector
+	jp	panic		; 25: Extended BIOS vector
+	jp	panic		; 26: Extended BIOS vector
+	jp	panic		; 27: Extended BIOS vector
+;
+;
+;
+sysinit:
+	;ld	a,0
+	;jp	panic
+	
+	ld	hl,str_banner
+	call	prtstr
+	call	conread
+	
+	ld	b,BF_SYSGET		; HBIOS SysGet function
+	ld	c,BF_SYSGET_BOOTINFO	; BootInfo sub-function
+	rst	08			; do it, boot disk device unit in 
+	ld	a,d			; boot unit id returned in D
+	ld	(hb_dev),a		; save for disk I/O
+	
+	; sysinit is being called twice during startup.  Once from
+	; the bootstrap and then from the interpreter.  So, we
+	; remap the vector here to avoid doing the above stuff
+	; multiple times.
+	ld	hl,sysinit1		; re-vector to sysinit1
+	ld	(bios_loc+1),hl		; update the jump table
+
+sysinit1:
+	xor	a		; signal success
+	ret			; done
+
+syshalt:
+	;ld	a,1
+	;jp	panic
+
+	; The syshalt vector does not seem be to invoked when
+	; selecting the Halt option from the p-System menu.
+	; I have no idea why.
+	ld	b,BF_SYSRESET	; HBIOS reset function
+	ld	c,BF_SYSRES_WARM	; warm reset is fine
+	rst	08		; do it
+	
+	; we should never get here
+	di			; interrupts off
+	halt			; ... and die
+	
+
+coninit:
+	;ld	a,2
+	;jp	panic
+
+	xor	a		; signal success
+	ret			; done
+
+constat:
+	;ld	a,3
+	;jp	panic
+
+	ld	b,BF_CIOIST	; serial port status function
+	ld	c,0		; port 0
+	rst	08		; call HBIOS
+	ld	c,0		; assume no chars pendin
+	jr	z,constat1	; if zero, no chars waiting
+	ld	c,$FF		; signal char(s) pending
+constat1:
+	xor	a		; signal success
+	ret			; done
+
+conread:
+	;ld	a,4
+	;jp	panic
+
+	ld	b,BF_CIOIN	; serial port read function
+	ld	c,0		; port 0
+	rst	08		; call HBIOS
+	ld	c,e		; char to C
+	xor	a		; signal success
+	ret			; done
+
+conwrit:
+	;ld	a,5
+	;jp	panic
+	
+	ld	a,c
+	cp	27		; escape?
+	jr	nz,conwrit1	; if not, handle normally
+	call	conwrit1	; else, send escape
+	ld	c,'['		; ... followed by '[' for ANSI
+conwrit1:
+	ld	e,c		; char to write to E
+	ld	b,BF_CIOOUT	; serial port write function
+	ld	c,0		; port 0
+	rst	08		; call HBIOS
+	xor	a		; signal success
+	ret			; done
+
+setdisk:
+	;ld	a,6
+	;jp	panic
+
+	ld	a,c		; disk number to A
+	ld	(curdisk),a	; save for later
+	xor	a		; signal success
+	ret			; done
+
+settrak:
+	;ld	a,7
+	;jp	panic
+
+	ld	a,c		; track number to A
+	ld	(curtrak),a	; save for later
+	xor	a		; signal success
+	ret			; done
+
+setsect:
+	;ld	a,8
+	;jp	panic
+	
+	ld	a,c		; sector number to A
+	dec	a		; from 1 indexed to 0 indexed
+	ld	(cursect),a	; save for later
+	xor	a		; signal success
+	ret
+
+setbufr:
+	;ld	a,9
+	;jp	panic
+	
+	ld	(curbufr),bc	; save buf adr for later
+	xor	a		; signal success
+	ret			; done
+
+dskread:
+	;ld	a,10
+	;jp	panic
+
+	;ld	a,(curdisk)
+	;cp	0
+	;jr	nz,dskinit1
+	
+	call	chkdisk
+	ret	nz
+
+	call	seek
+	ret	nz
+
+	ld	b,BF_DIOREAD	; HBIOS disk read function
+	ld	a,(hb_dev)	; HBIOS disk unit
+	ld	c,a		; ... goes in C
+	ld	a,(HB_CURBNK)	; get current memory bank
+	ld	d,a		; use as target bank for transfer
+	ld	e,1		; read 1 sector
+	ld	hl,(curbufr)	; disk read buffer adr
+	rst	08		; do it
+	ret	z		; return if good read
+	ld	a,ior_badblk	; else i/o error
+	ret			; done
+	
+dskwrit:
+	;ld	a,11
+	;jp	panic
+
+	call	chkdisk
+	ret	nz
+
+	call	seek
+	ret	nz
+
+	ld	b,BF_DIOWRITE	; HBIOS disk read function
+	ld	a,(hb_dev)	; HBIOS disk unit
+	ld	c,a		; ... goes in C
+	ld	a,(HB_CURBNK)	; get current memory bank
+	ld	d,a		; use as target bank for transfer
+	ld	e,1		; read 1 sector
+	ld	hl,(curbufr)	; disk read buffer adr
+	rst	08		; do it
+	ret	z		; return if good read
+	ld	a,ior_badblk	; else i/o error
+	ret			; done
+
+dskinit:
+	;ld	a,12
+	;jp	panic
+	
+	call	chkdisk
+	ret	nz
+
+	xor	a		; signal success
+	ret			; done
+
+dskstrt:
+	;ld	a,13
+	;jp	panic
+
+	xor	a		; signal success
+	ret			; done
+
+dskstop:
+	;ld	a,14
+	;jp	panic
+
+	xor	a		; signal success
+	ret			; done
+
+chkdisk:
+	; Validate that curdisk is <= max supported
+	ld	a,(curdisk)	; get current disk
+	cp	disks		; compare to disk count
+	jr	nc,chkdisk1	; if too high, go to err
+	xor	a		; signal success
+	ret			; done
+chkdisk1:
+	ld	a,ior_novol	; signal not online
+	or	a
+	ret
+
+seek:
+	; A single physical HBIOS disk device will contain p-System
+	; volume slices.  Each slice will be 8MB.  Start by computing
+	; a track offset using the p-System disk number as an
+	; index.  <Track Offset> = 8MB * <Disk Number>
+	; A track contains 0x20000 bytes:
+	;     512 (bytes per sec) * 16 (sec per trk) * 16 (hds per cyl)
+	; So, 8MB / 0x20000 = 0x40 tracks
+	ld	hl,0		; starting unit track offset
+	ld	de,$0040	; per disk track offset
+	ld	a,(curdisk)	; get current disk
+	or	a		; set flags
+	jr	z,seek2		; disk 0 needs no offset
+	ld	b,a		; into B for loop counter
+seek1:
+	add	hl,de		; add another offset
+	djnz	seek1		; and loop as needed
+seek2:
+	push	hl		; save total track offset
+	ld	a,(curtrak)	; get current track value
+	push	af		; save track value
+	and	$0F		; head is low 4 bits of track
+	ld	d,a		; save in D for head
+	pop	af		; recover original track value
+	rra			; rotate to remove head bits
+	rra
+	rra
+	rra
+	and	$0F		; mask off other bits
+	ld	l,a		; save in low byte of HL
+	ld	h,0		; zero out high byte of HL
+	ld	a,(cursect)	; get sector
+	ld	e,a		; put in E
+	pop	bc
+	add	hl,bc		; add track offset
+	ld	b,BF_DIOSEEK	; HBIOS seek function
+	ld	a,(hb_dev)	; HBIOS disk unit
+	ld	c,a		; ... goes in C
+	rst	08		; do it
+	ret	z		; if no error, done
+	ld	a,ior_badblk	; signal I/O error
+	ret			; done
+
+prtstr:
+	ld	a,(hl)
+	or	a
+	ret	z
+	push	hl
+	ld	c,a
+	call	conwrit
+	pop	hl
+	inc	hl
+	jr	prtstr
+
+
+panic:
+	di
+	halt
+
+
+hb_dev	.db	3		; HBIOS disk device unit
+;
+curdisk	.db	0		; Current disk number
+curtrak	.db	0		; Current track number
+cursect	.db	0		; Current sector number
+curbufr	.dw	0		; Current disk buffer address
+;
+str_banner	.db	13,10,"RomWBW p-System BIOS v"
+		.db	BIOSVER
+		.db	13,10,13,10
+		.db	"Press any key...",0
+;
+;
+;
+	.fill	bios_end - $
+	
+;
+	.end
diff --git a/Source/pSys/biostest.dat b/Source/pSys/biostest.dat
new file mode 100644
index 00000000..b1b0f82a
Binary files /dev/null and b/Source/pSys/biostest.dat differ
diff --git a/Source/pSys/blank.vol b/Source/pSys/blank.vol
new file mode 100644
index 00000000..67df0994
Binary files /dev/null and b/Source/pSys/blank.vol differ
diff --git a/Source/pSys/boot.dat b/Source/pSys/boot.dat
new file mode 100644
index 00000000..a23b59a5
Binary files /dev/null and b/Source/pSys/boot.dat differ
diff --git a/Source/pSys/fill.dat b/Source/pSys/fill.dat
new file mode 100644
index 00000000..3f8cdec5
Binary files /dev/null and b/Source/pSys/fill.dat differ
diff --git a/Source/pSys/loader.asm b/Source/pSys/loader.asm
new file mode 100644
index 00000000..b03cf965
--- /dev/null
+++ b/Source/pSys/loader.asm
@@ -0,0 +1,375 @@
+;===============================================================================
+; LOADER.ASM
+;
+; BOOTLOADER FOR ROMWBW PSYSTEM
+;
+; CP/M DISK FORMATS ALLOW FOR RESERVED TRACKS THAT CONTAIN AN IMAGE OF THE
+; OPERATING SYSTEM TO BE LOADED WHEN THE DISK IS BOOTED.  THE OPERATING SYSTEM
+; IMAGE ITSELF IS NORMALLY PREFIXED BY A 1-N SECTORS CONTAINING OS BOOTSTRAP
+; CODE AND DISK METADATA.
+;
+; THE RETROBREW COMPUTING GROUP HAS BEEN USING A CONVENTION OF PREFIXING THE
+; OS IMAGE WITH 3 SECTORS (512 BYTES X 3 FOR A TOTAL OF 1536 BYTES):
+;
+;   SECTOR 1: IBM-PC STYLE BOOT BLOCK CONTAINING BOOTSTRAP, 
+;             PARTITION TABLE, AND BOOT SIGNATURE
+;   SECTOR 2: RESERVED
+;   SECTOR 3: METADATA
+;
+; THE HARDWARE BIOS IS EXPECTED TO READ AND LOAD THE FIRST TWO SECTORS FROM THE
+; DISK TO MEMORY ADDRESS $8000 AND JUMP TO THAT LOCATION TO BEGIN THE BOOT
+; PROCESS.  THE BIOS IS EXPECTED TO VERIFY THAT A STANDARD BOOT SIGNATURE
+; OF $55, $AA IS PRESENT AT OFFSET $1FE-$1FF.  IF THE SIGNATURE IS NOT FOUND,
+; THE BIOS SHOULD ASSUME THE DISK HAS NOT BEEN PROPERLY INITIALIZED AND SHOULD
+; NOT JUMP TO THE LOAD ADDRESS.
+;
+;===============================================================================
+;
+#INCLUDE "../ver.inc"
+;
+#INCLUDE "psys.inc"
+;
+SYS_ENT		.EQU	$0100		; SYSTEM (OS) ENTRY POINT ADDRESS
+SYS_LOC		.EQU	$0100		; STARTING ADDRESS TO LOAD SYSTEM IMAGE
+SYS_END		.EQU	$0100 + loader_size + bios_size + boot_size		; ENDING ADDRESS OF SYSTEM IMAGE
+;
+SEC_SIZE	.EQU	512		; DISK SECTOR SIZE
+BLK_SIZE	.EQU	128		; OS BLOCK/RECORD SIZE
+;
+PREFIX_SIZE	.EQU	(SEC_SIZE * 3)	; 3 SECTORS
+;
+META_SIZE	.EQU	32		; SEE BELOW
+META_LOC	.EQU	(PREFIX_SIZE - META_SIZE)
+;
+PT_LOC		.EQU	$1BE
+PT_SIZ		.EQU	$40
+;
+		.ORG	0
+;
+;-------------------------------------------------------------------------------
+; SECTOR 1
+;
+;   THIS SECTOR FOLLOWS THE CONVENTIONS OF AN IBM-PC MBR CONTAINING THE OS
+;   BOOTSTRAP CODE, PARTITION TABLE, AND BOOT SIGNATURE
+;
+;----------------------------------------------------------------------------
+;
+	.FILL	PT_LOC - $,0		; FILL TO START OF PARTITION TABLE
+;
+; RESERVE SPACE FOR STANDARD IBM-PC PARTITION TABLE.  ALTHOUGH A
+; PARTITION TABLE IS NOT RELEVANT FOR A FLOPPY DISK, IT DOES NO HARM.
+; THE CONTENTS OF THE PARTITION TABLE MUST BE MANAGED BY FDISK80.
+;
+PARTTBL	.FILL	PT_SIZ,0		; PARTITION TABLE, FILL WITH ZEROES
+;
+; THE END OF THE FIRST SECTOR MUST CONTAIN THE TWO BYTE BOOT SIGNATURE.
+;
+BOOTSIG	.DB	$55,$AA			; STANDARD BOOT SIGNATURE
+;
+;-------------------------------------------------------------------------------
+; SECTOR 2
+;
+;   THIS SECTOR HAS NOT BEEN DEFINED AND IS RESERVED.
+;
+;----------------------------------------------------------------------------
+;
+	.FILL	SEC_SIZE,0			; JUST FILL SECTOR WITH ZEROES
+;
+;-------------------------------------------------------------------------------
+; SECTOR 3
+;
+;   OS AND DISK METADATA
+;
+;----------------------------------------------------------------------------
+;
+	.FILL	(BLK_SIZE * 3),0	; FIRST 384 BYTES ARE NOT YET DEFINED
+;
+; THE FOLLOWING TWO BYTES ARE AN ADDITIONAL SIGNATURE THAT IS VERIFIED BY
+; SOME HARDWARE BIOSES.
+;
+PR_SIG		.DB	$5A,$A5		; SIGNATURE GOES HERE
+;
+		.FILL	(META_LOC - $),0
+;
+; METADATA
+;
+PR_WP		.DB	0		; (1) WRITE PROTECT BOOLEAN
+PR_UPDSEQ	.DW	0		; (2) PREFIX UPDATE SEQUENCE NUMBER (DEPRECATED?)
+PR_VER		.DB	RMJ,RMN,RUP,RTP	; (4) OS BUILD VERSION
+PR_LABEL	.DB	"Unlabeled$$$$$$$","$"	; (17) DISK LABEL (EXACTLY 16 BYTES!!!)
+		.DW	0		; (2) DEPRECATED
+PR_LDLOC	.DW	SYS_LOC		; (2) ADDRESS TO START LOADING SYSTEM
+PR_LDEND	.DW	SYS_END		; (2) ADDRESS TO STOP LOADING SYSTEM
+PR_ENTRY	.DW	SYS_ENT		; (2) ADDRESS TO ENTER SYSTEM (OS)
+;
+#IF (META_SIZE != ($ - META_LOC))
+	.ECHO "META_SIZE VALUE IS WRONG!!!\r\n"
+	!!!
+#ENDIF
+;
+#IF ($ != PREFIX_SIZE)
+	.ECHO "LOADER PREFIX IS WRONG SIZE!!!\r\n"
+	!!!
+#ENDIF
+;
+;-------------------------------------------------------------------------------
+; SECTOR 4+
+;
+;   PSYSTEM LOADER
+;    - LOAD SBIOS TO HIGH MEMORY (JUST BELOW HBIOS PROXY)
+;    - LOAD PSYSTEM BOOTSTRAP & JUMP TO IT
+;
+;----------------------------------------------------------------------------
+;
+#include "../HBIOS/hbios.inc"
+;
+;
+bel	.equ	7	; ASCII bell
+bs	.equ	8	; ASCII backspace
+lf	.equ	10	; ASCII linefeed
+cr	.equ	13	; ASCII carriage return
+;
+interp_base	.equ	$0100		; first loc used by the interpreter
+low_memory	.equ	$0100		; lowest available ram location
+interleave	.equ	1		; interleaving factor (n:1)
+first_track	.equ	1		; first interleaved track
+skew		.equ	0		; track-to-track skew
+;
+;
+;
+	.org	loader_loc
+;
+	ld	sp,stack		; setup private stack
+;
+	call	nl2			; formatting
+	ld	hl,str_banner		; display boot banner
+	call	pstr			; do it
+;
+; Copy BIOS to running location
+;
+	ld	hl,loader_end		; BIOS image is at end of loader
+	ld	de,bios_loc		; BIOS execution location
+	ld	bc,bios_size		; Size of BIOS
+	ldir				; do it
+;
+; Copy p-System bootstrap to running location
+;
+	ld	hl,loader_end + bios_size	; bootstrap appended after BIOS
+	ld	de,boot_loc			; bootstrap runs here
+	ld	bc,boot_size			; size of bootstrap code
+	ldir					; do it
+;
+; Print some interesting info
+;
+	call	nl2			; spacing
+	ld	hl,str_info		; info string
+	call	pstr			; print it
+	ld	bc,bios_loc		; bios location adr
+	call	prthexword		; print it
+	ld	hl,str_info2		; additional info string
+	call	pstr			; print it
+	ld	bc,boot_loc		; bootstrap location adr
+	call	prthexword		; print it
+	call	nl2			; spacing
+;
+; Push key values onto the stack
+;
+	ld	hl,seclen	; maximum number of bytes per sector
+	push	hl                
+	ld	hl,sectors	; maximum number of sectors in table
+	push	hl                
+	ld	hl,skew		; track-to-track skew
+	push	hl                
+	ld	hl,first_track	; first interleaved track
+	push	hl                
+	ld	hl,interleave	; interleaving factor
+	push	hl                
+	ld	hl,seclen	; bytes per sector
+	push	hl                
+	ld	hl,sectors	; sectors per track
+	push	hl                
+	ld	hl,tracks	; tracks per disk
+	push	hl
+	ld	hl,bios_loc-2	; top word of available ram - sbios address-2
+	push	hl                
+	ld	hl,low_memory	; bottom word of available ram
+	push	hl                
+	ld	hl,bios_loc	; address of BIOS (start of jump table)
+	push	hl                
+	ld	hl,interp_base	; starting address of the interpreter
+	push	hl
+#if testbios
+	;ld	hl,disks-1	; maximum (highest) disk drive number
+	;push	hl
+#endif
+;
+	jp	boot_loc	; jump to bootloader
+;
+	ret
+;
+;
+; Print string at HL on console, null terminated
+;
+pstr:
+	ld	a,(hl)			; get next character
+	or	a			; set flags
+	inc	hl			; bump pointer regardless
+	ret	z			; done if null
+	call	cout			; display character
+	jr	pstr			; loop till done
+;
+; Print volume label string at HL, '$' terminated, 16 chars max
+;
+pvol:
+	ld	b,16			; init max char downcounter
+pvol1:
+	ld	a,(hl)			; get next character
+	cp	'$'			; set flags
+	inc	hl			; bump pointer regardless
+	ret	z			; done if null
+	call	cout			; display character
+	djnz	pvol1			; loop till done
+	ret				; hit max of 16 chars
+;
+; Start a newline on console (cr/lf)
+;
+nl2:
+	call	nl			; double newline
+nl:
+	ld	a,cr			; cr
+	call	cout			; send it
+	ld	a,lf			; lf
+	jp	cout			; send it and return
+;
+; Print a dot on console
+;
+pdot:
+	push	af
+	ld	a,'.'
+	call	cout
+	pop	af
+	ret
+;
+; Print the hex byte value in A
+;
+prthexbyte:
+	push	af
+	push	de
+	call	hexascii
+	ld	a,d
+	call	cout
+	ld	a,e
+	call	cout
+	pop	de
+	pop	af
+	ret
+;
+; Print the hex word value in BC
+;
+prthexword:
+	push	af
+	ld	a,b
+	call	prthexbyte
+	ld	a,c
+	call	prthexbyte
+	pop	af
+	ret
+;
+; Convert binary value in A to ASCII hex characters in DE
+;
+hexascii:
+	ld	d,a
+	call	hexconv
+	ld	e,a
+	ld	a,d
+	rlca
+	rlca
+	rlca
+	rlca
+	call	hexconv
+	ld	d,a
+	ret
+;
+; Convert low nibble of A to ASCII hex
+;
+hexconv:
+	and	0Fh	     ; low nibble only
+	add	a,90h
+	daa
+	adc	a,40h
+	daa
+	ret
+;
+; Output character from A
+;
+cout:
+	; Save all incoming registers
+	push	af
+	push	bc
+	push	de
+	push	hl
+;
+	; Output character to console via HBIOS
+	ld	e,a			; output char to E
+	ld	c,CIO_CONSOLE		; console unit to C
+	ld	b,BF_CIOOUT		; HBIOS func: output char
+	rst	08			; HBIOS outputs character
+;
+	; Restore all registers
+	pop	hl
+	pop	de
+	pop	bc
+	pop	af
+	ret
+;
+; Input character to A
+;
+cin:
+	; Save incoming registers (AF is output)
+	push	bc
+	push	de
+	push	hl
+;
+	; Input character from console via hbios
+	ld	c,CIO_CONSOLE		; console unit to c
+	ld	b,BF_CIOIN		; HBIOS func: input char
+	rst	08			; HBIOS reads character
+	ld	a,e			; move character to A for return
+;
+	; Restore registers (AF is output)
+	pop	hl
+	pop	de
+	pop	bc
+	ret
+;
+; Return input status in A (0 = no char, != 0 char waiting)
+;
+cst:
+	; Save incoming registers (AF is output)
+	push	bc
+	push	de
+	push	hl
+;
+	; Get console input status via HBIOS
+	ld	c,CIO_CONSOLE		; console unit to C
+	ld	b,BF_CIOIST		; HBIOS func: input status
+	rst	08			; HBIOS returns status in A
+;
+	; Restore registers (AF is output)
+	pop	hl
+	pop	de
+	pop	bc
+	ret
+;
+str_banner	.db	"RomWBW HBIOS p-System Loader v"
+		.db	BIOSVER
+		.db	0
+str_info	.db	"Loading pSystem BIOS @ 0x",0
+str_info2	.db	", Bootstrap @ 0x",0
+;
+	.fill	32,0
+stack	.equ	$
+;
+	.fill	loader_end - $
+;
+	.end
diff --git a/Source/pSys/psys.inc b/Source/pSys/psys.inc
new file mode 100644
index 00000000..44039ede
--- /dev/null
+++ b/Source/pSys/psys.inc
@@ -0,0 +1,32 @@
+testbios	.equ	0
+;
+; p-System Loader
+;
+loader_size	.equ	$200
+loader_loc	.equ	$100
+loader_end	.equ	loader_loc + loader_size
+;
+; p-System BIOS
+;
+bios_size	.equ	$200
+bios_loc	.equ	$FE00 - bios_size
+bios_end	.equ	bios_loc + bios_size
+;
+; p-System Bootstrap
+;
+#if testbios
+boot_size	.equ	$300
+boot_loc	.equ	$8000
+boot_end	.equ	boot_loc + boot_size
+#else
+boot_size	.equ	$800
+boot_loc	.equ	$8200
+boot_end	.equ	boot_loc + boot_size
+#endif
+;
+; Disk geometry
+;
+seclen		.equ	512	; bytes per sector
+sectors		.equ	16	; sectors per track
+tracks		.equ	192	; tracks per disk
+disks		.equ	6	; number of pSystem disk devices
diff --git a/Source/pSys/psys.vol b/Source/pSys/psys.vol
new file mode 100644
index 00000000..f6baa181
Binary files /dev/null and b/Source/pSys/psys.vol differ
diff --git a/Source/ver.inc b/Source/ver.inc
index 04683e23..ca8935b0 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.191"
+#DEFINE BIOSVER	"3.1.1-pre.192"
diff --git a/Source/ver.lib b/Source/ver.lib
index 1974dabc..81ca464a 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.191"
+	db	"3.1.1-pre.192"
 	endm
diff --git a/Tools/simh/Sim.cfg b/Tools/simh/Sim.cfg
index dc1e25ab..b21c037d 100644
--- a/Tools/simh/Sim.cfg
+++ b/Tools/simh/Sim.cfg
@@ -24,6 +24,7 @@ attach n8vem0 %1
 ; hard disks
 ;set hdsk debug=read;write;verbose
 attach hdsk0 ..\..\Binary\hd512_combo.img
+;attach hdsk0 ..\..\Binary\psys.img
 attach hdsk1 ..\..\Binary\hd1024_combo.img
 set hdsk0 format=HDSK
 set hdsk1 format=HDSK