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RomWBW Getting Started

Wayne Warthen (mailto:wwarthen@gmail.com)
08 Dec 2021











RomWBW

Z80/Z180 System Software

Version 3.1 Pre-release
08 Dec 2021

Wayne Warthen wwarthen@gmail.com

Download

- RomWBW Distribution Package

Related Pages

- RomWBW Architecture Document
- RomWBW Applications
- RomWBW Errata

Overview

RomWBW provides a complete software system for a wide variety of
hobbyist Z80/Z180 CPU-based systems produced by these developer
communities:

- RetroBrew Computers
- RC2014
- retro-comp

General features include:

- Banked memory services for several banking designs
- Disk drivers for RAM, ROM, Floppy, IDE, CF, and SD
- Serial drivers including UART (16550-like), ASCI, ACIA, SIO
- Video drivers including TMS9918, SY6545, MOS8563, HD6445
- Real time clock drivers including DS1302, BQ4845
- Multiple OS support including CP/M 2.2, ZSDOS, CP/M 3, ZPM3
- Built-in VT-100 terminal emulation support

RomWBW is distributed as both source code and pre-built ROM and disk
images. Some of the provided software can be launched directly from the
ROM firmware itself:

- System Monitor
- Operating Systems (CP/M 2.2, ZSDOS)
- ROM BASIC (Nascom BASIC and Tasty BASIC)
- ROM Forth

A dynamic disk drive letter assignment mechanism allows mapping
operating system drive letters to any available disk media.
Additionally, mass media devices (IDE Disk, CF Card, SD Card) support
the use of multiple slices (up to 256 per device). Each slice contains a
complete CP/M filesystem and can be mapped independently to any drive
letter. This overcomes the inherent size limitations in legacy OSes and
allows up to 2GB of accessible storage on a single device.

The pre-built ROM firmware images are generally optimal for most users.
However, it is also very easy to modify and build custom ROM images that
fully tailor the firmware to your specific preferences. All tools
required to build custom ROM firmware are included – no need to install
assemblers, etc. Any modern computer running Windows, Linux, or MacOS
can be used.

Multiple disk images are provided in the distribution. Most disk images
contain a complete, bootable, ready-to-run implementation of a specific
operating system. A “combo” disk image contains multiple slices, each
with a full operating system implementation. If you use this disk image,
you can easily pick whichever operating system you want to boot without
changing media.

Installation

The latest RomWBW distribution downloads are maintained on GitHub in the
RomWBW Repository. The fully-built distributions are found on the
releases page of the repository. On this page, you will probably see
both pre-releases as well as normal releases. Unless you have a specific
reason, I suggest you stick to the most recent normal release (not
pre-release). Expand the “Assets” drop-down for the release you want to
download, then select the asset named RomWBW-vX.X.X-Package.zip. The
Package asset includes all pre-built ROM and Disk images as well as full
source code. The other assets are Source Code only and do not have the
pre-built ROM or disk images.

The pre-built ROM images will automatically detect and support a
reasonable range of devices including serial ports, video adapters,
on-board disk interfaces, and PropIO/ParPortProp boards without building
a custom ROM. The distribution is a .zip archive. After downloading it
to a working directory on your modern computer (Windows/Linux/Mac) use
any zip tool to extract the contents of the archive.

In general, you will just program your system’s ROM chip with the
appropriate ROM image from the RomWBW distribution. Depending on how you
got your system, you may have already been provided with a
pre-programmed ROM chip. If so, use that initially. Otherwise, you will
need to use a ROM programmer to initially program your ROM chip. Please
refer to the documentation that came with your ROM programmer for more
information. Once you have a running RomWBW system, you can generally
update your ROM to a newer version in-situ with an included ROM Flashing
tool (Will Sowerbutts’ FLASH application) as described in the Upgrading
section below.

Looking at the extracted distribution archive, You will see that the
distribution is broken up into a few sub-directories. The Binary
directory contains the pre-built ROM and disk images. The ROM image
files all end in “.rom”. Based on the table below, carefully pick the
appropriate ROM image for your hardware.

-------------------------------------------------------------------------
Platform ROM Image File Baud Description
---------- ----------------- -------- -----------------------------------
SBC SBC_std.rom 38400 RetroBrew SBC v1 or v2 ECB Z80

Zeta V1 ZETA_std.rom 38400 RetroBrew Zeta V1 Z80, ParPortProp
(optional)

Zeta V2 ZETA2_std.rom 38400 RetroBrew Zeta V2 Z80, ParPortProp
(optional)

N8 N8_std.rom 38400 RetroBrew N8 Z180, date code >=
2312

Mark IV MK4_std.rom 38400 RetroBrew Mark IV ECB Z180

RC Z80 RCZ80_std.rom 115200 RC2014 w/ Z80 CPU, requires 512K
RAM/ROM module

RC Z180* RCZ180_ext.rom 115200 RC2014 w/ Z180 CPU & 512K banked
RAM/ROM module

RC Z180* RCZ180_nat.rom 115200 RC2014 w/ Z180 CPU & 512K native
RAM/ROM module

Easy Z80 EZZ80_std.rom 115200 Sergey Kiselev’s Easy Z80

SC126 SCZ180_126.rom 115200 Stephen Cousin’s SC126 Z180

SC130 SCZ180_130.rom 115200 Stephen Cousin’s SC130 Z180

SC131 SCZ180_131.rom 115200 Stephen Cousin’s SC131 Z180

Dyno DYNO_std.rom 38400 Steve Garcia’s Z180 Dyno Computer

MBC MBC_std.rom 38400 Andrew Lynch’s Multi Board Computer
-------------------------------------------------------------------------

*The RC2014 Z180 requires a separate RAM/ROM memory module. There are
two types of these modules and you must pick the ROM for your type of
memory module. The “ext” ROM supports Spencer’s official 512K RAM/ROM
banked memory module. The “nat” ROM supports any of the third-party Z180
native memory modules.

RomWBW will automatically attempt to detect and support typical add-on
components for each of the systems supported. More information on the
required system configuration and optional supported components for each
ROM is found in the file called “RomList.txt” in the Binary directory.
All pre-built ROM images are simple 512KB binary images. If your system
utilizes a larger ROM chip, you can just program the image into the
first 512KB of the ROM.

Connect a serial terminal or computer with terminal emulation software
to the primary serial port of your CPU board. You may need to refer to
your hardware provider’s documentation for details. A null-modem
connection may be required. Set the baud rate as indicated in the table
above. Set the line characteristics to 8 data bits, 1 stop bit, no
parity, and no flow control. If possible, select VT-100 terminal
emulation.

Upon power-up, your terminal should display a sign-on banner within 2
seconds followed by hardware inventory and discovery information. When
hardware initialization is completed, a boot loader prompt allows you to
choose a ROM-based operating system, system monitor, application, or
boot from a disk device.

Initially, you should try the ROM boot options. By selecting either CP/M
2.2 or Z-System, the selected operating system will be loaded from ROM
and you will see the a B> disk prompt. In this scenario, A: will be an
empty RAM disk and B: will refer to your ROM disk containing some common
applications. This provides a simple environment for learning to use
your system. Be aware that files saved to the RAM disk (A:) will
disappear at the next power on (RAM is generally not persistent). Also
note that attempts to save files to the ROM disk (B:) will fail because
ROM is not writable under normal circumstances.

General Usage

Each of the operating systems and ROM applications included with RomWBW
are sophisticated tools in their own right. It is not reasonable to
document their usage here. However, you will find complete manuals in
PDF format in the Doc directory of the distribution. The intention of
this section is to document the RomWBW specific enhancements to these
operating systems.

Inbuilt ROM Applications

In addition to CP/M 2.2 and Z-System, there are several ROM applications
that can be launched directly from ROM. These applications are not
hosted by an operating system and so they are unable to save files to
disk devices.

The following ROM applications are available at the boot loader prompt:

Application
-------------- --------------------------------------------------------
Monitor Z80 system debug monitor w/ Intel Hex loader
Forth Brad Rodriguez’s ANSI compatible Forth language
Basic Nascom 8K BASIC language
Tasty BASIC Dimitri Theuling’s Tiny BASIC implementation
Play A simple video game (requires ANSI terminal emulation)
Network Boot Boot through Wiznet MT011 device
Flash Update Upload and flash a new ROMWBW image using xmodem

In general, the command to exit these applications and restart the
system is BYE. The exceptions are the Monitor which uses B and Play
which uses Q.

Space is available in the ROM image for the inclusion of other software.
Any inbuilt application can be set up to launch automatically at
startup.

Devices and Units

In order to support a wide variety of hardware, RomWBW HBIOS uses a
modular approach to implementing device drivers and presenting devices
to the operating system. In general, all devices are classified as one
of the following:

- Disk (Hard Disk, CF Card, SD Card, RAM/ROM Disk, etc.)
- Character (Serial Ports, Parallel Ports, etc.)
- Video (Video Display/Keyboard Interfaces)
- RTC/NVRAM (Real Time Clock, Non-volatile RAM)

HBIOS uses the concept of unit numbers to present a complex set of
hardware devices to the operating system. As an example, a typical
system might have a ROM Disk, RAM Disk, Floppy Drives, and Disk Drives.
All of these are considered Disk devices and are presented to the
operating system as generic block devices. This means that the operating
system does not need to understand the difference between a floppy drive
and a ROM disk.

As RomWBW boots, it assigns a unit number to each device. This unit
number is used by the operating system to refer to the device. It is,
therefore, important to know the unit number assigned to each device.
This information is displayed in the unit summary table at startup. Here
is an example:

Unit Device Type Capacity/Mode
---------- ---------- ---------------- --------------------
Char 0 UART0: RS-232 38400,8,N,1
Char 1 UART1: RS-232 38400,8,N,1
Disk 0 MD1: RAM Disk 384KB,LBA
Disk 1 MD0: ROM Disk 384KB,LBA
Disk 2 FD0: Floppy Disk 3.5",DS/HD,CHS
Disk 3 FD1: Floppy Disk 3.5",DS/HD,CHS
Disk 4 IDE0: CompactFlash 3815MB,LBA
Disk 5 IDE1: Hard Disk --
Disk 6 PRPSD0: SD Card 1886MB,LBA
Video 0 CVDU0: CRT Text,80x25

In this example, you can see that the system has a total of 7 Disk Units
numbered 0-6. There are also 2 Character Units and 1 Video Unit. The
table shows the unit numbers assigned to each of the devices. Notice how
the unit numbers are assigned sequentially regardless of the specific
device.

There may or may not be media in the disk devices listed. For example,
the floppy disk devices (Disk Units 2 & 3) may not have a floppy in the
drive. Also note that Disk Unit 4 shows a disk capacity, but Disk Unit 5
does not. This is because the PPIDE interface of the system supports up
to two drives, but there is only one actual drive attached. A unit
number is assigned to all possible devices regardless of whether they
have actual media installed at boot time.

Note that Character Unit 0 is always the initial system console by
definition.

If your system has an RTC/NVRAM device, it will not be listed in the
unit summary table. Since only a single RTC/NVRAM device can exist in
one system, unit numbers are not required nor used for this type of
device.

Changing Console and Console speed

Your system can support a number of devices for the console. They may be
VDU type devices or serial devices. If you want to change which device
is the console, the I menu option can be used to choose the unit and
it’s speed.

The command format is I <u> [<c>]

where u is unit to select and c is the optional baud rate code as listed
below.

Code | Rate | Code | Rate | Code | Rate | Code | Rate |
------|----------|------|----------|------|----------|------|----------|
0 | 75 | 8 | 1800 | 16 | 28880 | 24 | 460800 |
1 | 150 | 9 | 2400 | 17 | 38400 | 25 | 614400 |
2 | 225 | 10 | 3600 | 18 | 57600 | 26 | 921600 |
3 | 300 | 11 | 4800 | 19 | 76800 | 27 | 1228822 |
4 | 450 | 12 | 7200 | 20 | 115200 | 28 | 1843200 |
5 | 600 | 13 | 9600 | 21 | 153600 | 29 | 2457600 |
6 | 900 | 14 | 14400 | 22 | 230400 | 30 | 3686400 |
7 | 1200 | 15 | 19200 | 23 | 307200 | 31 | 7372800 |
------------------------------------------------------------------------

Example: To change current console to 9600 baud

I 0 13

Drive Letter Assignment

In legacy CP/M-type operating systems, drive letters were generally
mapped to disk drives in a completely fixed way. For example, drive A:
would always refer to the first floppy drive. Since RomWBW supports a
wide variety of hardware configurations, it implements a much more
flexible drive letter assignment mechanism so that any drive letter can
be assigned to any disk device.

At boot, you will notice that RomWBW automatically assigns drive letters
to the available disk devices. These assignments are displayed during
the startup of the selected operating system. Additionally, you can
review the current drive assignments at any time using the ASSIGN
command. CP/M 3 and ZPM3 do not automatically display the assignments at
startup, but you can use ASSIGN do display them.

The drive letter assignments do not change during an OS session unless
you use the ASSIGN command yourself to do it. Additionally, the
assignments at boot will stay the same on each boot as long as you do
not make changes to your hardware configuration. Note that the
assignments are dependent on the media currently inserted in hard disk
drives. So, notice that if you insert or remove an SD Card or CF Card,
the drive assignments will change. Since drive letter assignments can
change, you must be careful when doing destructive things like using
CLRDIR to make sure the drive letter you use is referring to the desired
media.

When performing a ROM boot of an operating system, note that A: will be
your RAM disk and B: will be your ROM disk. When performing a disk boot,
the disk you are booting from will be assigned to A: and the rest of the
drive letters will be offset to accommodate this. This is done because
most legacy operating systems expect that A: will be the boot drive.

Slices

The vintage operating systems included with RomWBW were produced at a
time when mass storage devices were quite small. CP/M 2.2 could only
handle filesystems up to 8MB. In order to achieve compatibility across
all of the operating systems supported by RomWBW, the hard disk
filesystem format used is 8MB. This ensures any filesystem will be
accessible to any of the operating systems.

Since storage devices today are quite large, RomWBW implements a
mechanism called slicing to allow up to 256 8MB filesystems on a single
large storage device. This allows up to 2GB of usable space on a single
media. You can think of slices as a way to refer to any of the first 256
8MB chunks of space on a single media.

Of course, the problem is that CP/M-like operating systems have only 16
drive letters (A:-P:) available. Under the covers, RomWBW allows you to
use any drive letter to refer to any slice of any media. The ASSIGN
command allows you to view or change the drive letter mappings at any
time. At startup, the operating system will automatically allocate a
reasonable number of drive letters to the available storage devices. The
allocation will depend on the number of large storage devices available
at boot. For example, if you have only one hard disk type media, you
will see that 8 drive letters are assigned to the first 8 slices of that
media. If you have two large storage devices, you will see that each
device is allocated four drive letters.

Referring to slices within a storage device is done by appending a :
where is the device relative slice number from 0-255. For example, if
you have an IDE device, it will show up as IDE0: in the boot messages
meaning the first IDE device. To refer to the fourth slice of IDE0, you
would type “IDE0:3”. Here are some examples:

-------- ------------------------------
IDE0:0 First slice of disk in IDE0
IDE0: First slice of disk in IDE0
IDE0:3 Fourth slice of disk in IDE0
-------- ------------------------------

So, if I wanted to use drive letter L: to refer to the fourth slice of
IDE0, I could use the command ASSIGN L:=IDE0:3. There are a couple of
rules to be aware of when assigning drive letters. First, you may only
refer to a specific device/slice with one drive letter. Said another
way, you cannot have multiple drive letters referring to a single
device/slice at the same time. Second, there must always be a drive
assigned to A:. Any attempt to violate these rules will be blocked by
the ASSIGN command.

Unlike MS-DOS partitions, slices are not allocated – there is no
partitioning for slices. Think of every hard disk type device as having
a pre-allocated set of 256 8MB slices at the start of the media. You can
refer to any of them simply by assigning a drive letter. RomWBW will not
check to see if there is anything else on the hard disk in the slice you
are referring to, nor will it verify that the hard disk media is large
enough to have a slice at the location you refer to. If you attempt to
write past the end of your media, you will get an I/O error displayed,
so you will know if you make a mistake. There is no tracking of your use
of slices – you will need to keep track of your use of slices yourself.

Nothing automatically initializes a slice as a file system. You must do
that yourself using CLRDIR. Since CLRDIR works on drive letters, make
absolutely sure you know what media and slice are assigned to that drive
letter before using CLRDIR.

While it is probably obvious, you cannot use slices on any media less
than 8MB in size. Specifically, you cannot slice RAM disks, ROM disks,
floppy disks, etc.

RomWBW Custom Applications

The operation of the RomWBW hosted operating systems is enhanced through
several custom applications. These applications are functional on all of
the OS variants included with RomWBW.

The following custom applications are found on the ROM disk and are,
therefore, globally available.

-----------------------------------------------------------------------------
Application Description
------------- ---------------------------------------------------------------
ASSIGN Add, change, and delete drive letter assignments. Use ASSIGN /?
for usage instructions.

SYSCOPY Copy system image to a device to make it bootable. Use SYSCOPY
with no parms for usage instructions.

MODE Reconfigures serial ports dynamically.

FDU Format and test floppy disks. Menu driven interface.

FORMAT Will someday be a command line tool to format floppy disks.
Currently does nothing!

XM XModem file transfer program adapted to hardware. Automatically
uses primary serial port on system.

FLASH Will Sowerbutts’ in-situ ROM programming utility.

FDISK80 John Coffman’s Z80 hard disk partitioning tool. See
documentation in Doc directory.

TALK Direct console I/O to a specified character device.

RTC Manage and test the Real Time Clock hardware.

TIMER Display value of running periodic system timer.

INTTEST Test interrupt vector hooking.
-----------------------------------------------------------------------------

Some custom applications do not fit on the ROM disk. They are found on
the disk image files or the individual files can be found in the
Binary\Apps directory of the distribution.

Application Description
------------- -------------------------------------------------------------
TUNE Play .PT2, .PT3, .MYM audio files.
FAT Access MS-DOS FAT filesystems from RomWBW (based on FatFs).

Additional documentation on all of these applications can be found in
“RomWBW Applications.pdf” in the Doc directory of the distribution.

Using Disks

ROM & RAM Disks

RomWBW utilizes a portion of the ROM and RAM memory in your system to
implement small memory-based disks.

The RAM disk provides a small CP/M filesystem that you can use for the
temporary storage of files. Unless your system has a battery backed
mechanism for persisting your RAM contents, the RAM disk contents will
be lost at each power-off. However, the RAM disk is an excellent choice
for storing temporary files because it is very fast.

Like the RAM disk, the ROM disk also provides a small CP/M filesystem,
but it’s contents are static – they are part of the ROM. As such, you
cannot save files to the ROM disk. Any attempt to do this will result in
a disk I/O error. The contents of the ROM disk have been chosen to
provide a core set of tools and applications that are helpful for either
CP/M 2.2 or ZSDOS. Since ZSDOS is CP/M 2.2 compatible, this works fairly
well. However, you will find some files on the ROM disk that will work
with ZSDOS, but will not work on CP/M 2.2. For example, LDDS, which
loads the ZSDOS date/time stamper will only run on ZSDOS.

Disk Devices

While the RAM/ROM disks provide a functional system, they are not useful
in the long term because you cannot save data across power cycles. They
are also constrained by limited space.

The systems supported by RomWBW all have the ability to use persistent
disk media. A wide variety of disk devices are supported including
floppy drives, hard disks, CF Cards, and SD Cards. Some systems have
disk interfaces built-in, while others will require add-in cards. You
will need to refer to the documentation for your system for your
specific options.

In the RomWBW boot messages, you will see hardware discovery messages.
If you have a disk drive interface, you should see messages listing
device types like FD:, IDE:, PPIDE:, SD:. Additionally, you will see
messages indicating the media that has been found on the interfaces. As
an example, here are the messages you might see if you have an IDE
interface in your system with a single CF Card inserted in the primary
side of the interface:

IDE: IO=0x80 MODE=MK4
IDE0: 8-BIT LBA BLOCKS=0x00773800 SIZE=3815MB
IDE1: NO MEDIA

The messages you see will vary depending on your hardware and the media
you have installed. But, they will all have the same general format as
the example above.

Once your your system has working disk devices, you can boot an
operating system and the operating system will have access to the media.
At the boot loader prompt, select either either CP/M 2.2 or Z-System to
boot from ROM. As the operating system starts up, you should see a list
of drive letters assigned to the disk media you have installed. Here is
an example of this:

Configuring Drives...

A:=MD1:0
B:=MD0:0
C:=IDE0:0
D:=IDE0:1

You will probably see more drive letters than this. The drive letter
assignment process is described above in the Drive Letter Assignment
section. Be aware that RomWBW will only assign drive letters to disk
interfaces that actually have media in them. If you do not see drive
letters assigned as expected, refer to the prior system boot messages to
ensure media has been detected in the interface. Actually, there is one
exception to this rule: floppy drives will be assigned a drive letter
regardless of whether there is any media inserted at boot.

Notice how each drive letter refers back to a specific disk hardware
interface like IDE0. This is important as it is telling you what each
drive letter refers to. Also notice that mass storage disks (like IDE)
will normally have multiple drive letters assigned. The extra drive
letters refer to additional “slices” on the disk. The concept of slices
is described above in the Slices section.

Once you are seeing drive letters referring to your disk media, you can
follow the instructions below to begin using the disk media with the
operating system. Your disk media must be initialized prior to being
used. There are two ways to initialize your media for use.

One option is to initialize the media in-place using your RomWBW system.
This process is described below under Disk Initialization. In this
scenario, you will need to subsequently copy any files you want to use
onto the newly initialized disk (see Transferring Files).

Alternatively, you can use your modern Windows, Linux, or Mac computer
to copy a disk image onto the disk media. RomWBW comes with a variety of
disk images that are ready to use and have a much more complete set of
files than you will find on the ROM disk. This process is covered below
under Disk Images.

Disk Initialization

To use a disk device, you will need to initialize the directory of the
filesystem. On RomWBW, the initialization is done using the CLRDIR
application. For example if your C: drive has been assigned to a storage
device, you would use CLRDIR C: to initialize C: and prepare it hold
files. Note that CLRDIR will prompt you for confirmation and you must
respond with a capital ‘Y’ to confirm. Once CLDIR has completed, you can
copy files onto the drive, for example COPY *.* C:. Be very careful to
pay attention to your drive letter assignments prior to running CLRDIR
to avoid accidentally wiping out a filesystem that has data on it.

Running CLRDIR on a disk device is roughly equivalent to running FORMAT
on MS-DOS. Note that unlike MS-DOS you do not partition your mass
storage device. CP/M knows nothing about disk partitions. You may notice
a partitioning application on your ROM disk (FDISK80), but this is
strictly for an advanced technique of adding an MS-DOS FAT filesystem to
your media in addition to the CP/M area. Do not use FDISK80 unless you
are specifically attempting to add an MS-DOS FAT filesystem to your
media.

If you are using a floppy drive, you will need to physically format your
floppy disk prior to use. This is only required for floppy disks, not
hard disk, CF Cards, or SD Cards, etc. To format a floppy drive, you can
use the interactive application FDU. FDU is not terribly user friendly,
but is generally documented in the file “FDU.txt” found in the Doc
directory of the distribution. It is not necessary to run CLRDIR on a
floppy disk after physically formatting it – the directory is cleared as
part of the formatting.

Once you have initialized a disk device and copied your desired files
onto it, you may want to make the disk bootable. On CP/M filesystems,
you must perform one additional step to make a disk bootable.
Specifically, you need to place a copy of the operating system on the
system tracks of the disk. This is done using the SYSCOPY command. Let’s
say you have prepared drive C: by initializing it with CLRDIR and copied
some files onto it. You can now make C: bootable by running the
following command:

B>SYSCOPY C:=B:ZSYS.SYS

This command means: copy the Z-System operating system onto the system
tracks of drive C:. In this example, it is assumed that you have booted
from ROM, so B: is the ROM disk drive. Additionally, this example
assumes you want the Z-System operating system to be booted from C:. If
you want CP/M 2.2 instead, you would replace B:ZSYS.SYS with B:CPM.SYS.
Here is a full example of this process.

B>SYSCOPY C:=B:ZSYS.SYS

SYSCOPY v2.0 for RomWBW CP/M, 17-Feb-2020 (CP/M 2 Mode)
Copyright 2020, Wayne Warthen, GNU GPL v3

Transfer system image from B:ZSYS.SYS to C: (Y/N)? Y
Reading image... Writing image... Done

Once this process succeeds, you will be able to boot directly to the
disk from the boot loader prompt. See the instructions in Booting Disks
for details on this.

Disk Images

As mentioned previously, RomWBW includes a variety of disk images that
contain a full set of applications for the operating systems supported.
It is generally easier to use these disk images instead of copying all
the files over using XModem. You use your modern computer (Windows,
Linux, MacOS) to place the disk image onto the disk media, then just
move the media over to your system. In this scenario you do not run
CLRDIR or SYSCOPY on the drive(s). The directory is prepared and the
disk is already bootable, if it is an operating system boot disk image.

To copy the disk image files onto your actual media (floppy disk, CF
Card, SD Card, etc.), you need to use an image writing utility on your
modern computer. Your modern computer will need to have an appropriate
interface or slot that accepts the media. To actually copy the image,
you can use the dd command on Linux or MacOS. On Windows, in the “Tools”
directory of the distribution there are two tools you can use. For
floppy media, you can use RawWriteWin and for hard disk media, you can
use Win32DiskImager. In all cases, the image file should be written to
the media starting at the very first block or sector of the media. This
will destroy any other data on the media.

The disk image files are found in the Binary directory of the
distribution. Floppy disk images are prefixed with “fd_” and hard disk
images are prefixed with “hd_”. The floppy images are specifically for
1.44M floppy media only. Each disk image has the complete set of normal
applications and tools distributed with the associated operating system
or application suite.

The following table shows the disk image files available. Note that the
images in the “Hard” column are fine for use on CF Cards, SD Cards, as
well as real spinning hard disks.

Floppy Hard Description
-------------- -------------- ------------------------------
fd_cpm22.img hd_cpm22.img DRI CP/M 2.2 boot disk
fd_zsdos.img hd_zsdos.img ZSDOS 1.1 boot disk
fd_nzcom.img hd_nzcom.img NZCOM boot disk
fd_cpm3.img hd_cpm3.img DRI CP/M 3 boot disk
fd_zpm3.img hd_zpm3.img ZPM3 boot disk
fd_ws4.img hd_ws4.img WordStar v4 application disk

In addition to the disk images above, there is also a special hard disk
image called hd_combo.img. This image contains all of the images above,
but in a single image with 6 slices. At the boot loader prompt, you can
choose a disk with the combo image, then select the specific slice you
want. This allows a single disk to have all of the possible operating
system options.

This is the layout of the hd_combo disk image:

Slice Description
--------- ------------------------------
Slice 0 DRI CP/M 2.2 boot disk
Slice 1 ZSDOS 1.1 boot disk
Slice 2 NZCOM boot disk
Slice 3 DRI CP/M 3 boot disk
Slice 4 ZPM3 boot disk
Slice 5 WordStar v4 application disk

Note that unlike the ROM firmware, you do not need to choose a disk
image specific to your hardware. Because the RomWBW firmware provides a
hardware abstraction layer, all hard disk images will work on all
hardware variations. Yes, this means you can remove an SD Card from one
system and put it in a different system. The only constraint is that the
applications on the disk media must be up to date with the firmware on
the system being used.

All of the disk images that indicate they are bootable (boot disk) will
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.

Booting Disks

When starting your system, following the hardware initialization, you
will see the Boot Loader prompt. In addition, to the ROM boot options,
you will see another line listing the Disk boot options. This line lists
the disk devices that you can choose to boot directly.

You will notice that you do not have an option to boot a drive letter
here (like C:). This is because the operating system is not yet loaded.
When you ran SYSCOPY previously, remember that C: was assigned to IDE0:0
which means device IDE0, slice 0. So, to boot the disk that you just
setup with SYSCOPY, you would choose option 2. You will then be prompted
for the slice on IDE0 that you want to boot. For now, just press enter
to choose slice 0. Once you are familiar with slices, you can SYSCOPY
and boot alternate slices. Here is what you would see when booting to a
disk device:

MARK IV Boot Loader

ROM: (M)onitor (C)P/M (Z)-System (F)orth (B)ASIC (T)-BASIC (P)LAY (U)SER ROM
Disk: (0)MD1 (1)MD0 (2)IDE0 (3)IDE1

Boot Selection? 2 Slice(0-9)[0]?

Booting Disk Unit 2, Slice 0...

Reading disk information...
Loc=D000 End=FE00 Ent=E600 Label=Unlabeled Drive

Loading...

Following this, you would see the normal operating system startup
messages. However, your operating system prompt will be A> and when you
look at the drive letter assignments, you should see that A: has been
assigned to the disk you selected to boot.

If you receive the error message “Disk not bootable!”, you have either
failed to properly run SYSCOPY on the target disk or you have selected
the wrong disk/slice.

Note that although MD1 (RAM disk) and MD0 (ROM disk) drives are listed
in the Disk boot line, they are not “bootable” disks because they have
no system tracks on them. Attempting to boot to one of them, will fail
with a “Disk not bootable!” error message and return to the loader
prompt.

Operating Systems

One of the primary goals of RomWBW is to expose a set of generic
hardware functions that make it easy to adapt operating systems to any
hardware supported by RomWBW. As a result, there are now 5 operating
systems that have been adapted to run under RomWBW. The adaptations are
identical for all hardware supported by RomWBW because RomWBW hides all
hardware specifics from the operating system.

Note that all of the operating systems included with RomWBW support the
same basic filesystem format. As a result, a formatted filesystem will
be accessible to any operating system. The only possible issue is that
if you turn on date/time stamping using the newer OSes, the older OSes
will not understand this. Files will not be corrupted, but the date/time
stamps may be lost.

The following sections briefly describe the operating system options
currently available.

Digital Research CP/M 2.2

This is the most widely used variant of the Digital Research operating
system. It has the most basic feature set, but is essentially the
compatibility metric for all other CP/M-like operating systems including
all of those listed below. The Doc directory contains a manual for CP/M
usage (“CPM Manual.pdf”). If you are new to the CP/M world, I would
recommend using this CP/M variant to start with simply because it is the
most stable and you are less likely to encounter problems.

Notes

- You can change media, but it must be done while at the OS command
prompt and you must warm start CP/M by pressing ctrl-c. This is a
CP/M 2.2 constraint and is well documented in the DRI manuals.

- The original versions of DDT, DDTZ, and ZSID used the RST 38 vector
which conflicts with interrupt mode 1 use of this vector. The DDT,
DDTZ, and ZSID applications in RomWBW have been modified to use RST
30 to avoid this issue.

- Z-System applications will not run under CP/M 2.2. For example, the
LDDS date stamper will not run.

ZSDOS 1.1

ZSDOS is the most popular non-DRI CP/M “clone” which is generally
referred to as Z-System. Z-System is intended to be an enhanced version
of CP/M and should run all CP/M 2.2 applications. It is optimized for
the Z80 CPU (as opposed to 8080 for CP/M) and has some significant
improvements such as date/time stamping of files. For further
information on the RomWBW implementation of Z-System, see the wiki page
Z-System Notes. Additionally, the official documentation for Z-System is
included in the RomWBW distribution Doc directory (“ZSDOS Manual.pdf”
and “ZCPR Manual.pdf”).

Notes

- Although most CP/M 2.2 applications will run under Z-System, some
may not work as expected. The best example is PIP which is not aware
of the ZSDOS paths and will fail in some scenarios (use COPY
instead).

- Although ZSDOS can recognize a media change in some cases, it will
not always work. You should only change media at a command prompt
and be sure to warm start the OS with a ctrl-c.

NZCOM Automatic Z-System

NZCOM is a much further refined version of Z-System (ZCPR 3.4). NZCOM
was sold as an enhancement for existing users of CP/M 2.2 or ZSDOS. For
this reason, (by design) NZCOM does not provide a way to boot directly
from disk. Rather, it is loaded after the system boots into a host OS.
On the RomWBW NZCOM disk images, the boot OS is ZSDOS 1.1. After you
configure NZCOM, you can add a PROFILE.SUB file to automatically launch
NZCOM at boot.

NZCOM is not pre-configured. You must run through a simple configuration
process before loading it. Run MKZCM to do this.

NZCOM has substantially more functionality than CP/M or basic Z-System.
It is important to read the the “NZCOM Users Manual.pdf” file in the
RomWBW Doc directory.

Notes

- There is no DIR command, you must use SDZ instead. If you don’t like
this, look into the ALIAS facility.

Digital Research CP/M 3

This is the Digital Research follow-up product to their very popular
CP/M 2.2 operating system. While highly compatible with CP/M 2.2, it
features many enhancements. It makes direct use of banked memory to
increase the user program space (TPA). It also has a new suite of
support tools and help system.

Note that to make a CP/M 3 boot disk, you actually place CPMLDR.SYS on
the system tracks of the disk. You do not place CPM3.SYS on the system
tracks. CPMLDR.SYS chain loads CPM3.SYS.

Notes

- The DATE command cannot yet be used to set the RTC. The RTC is used
to read the current date/time for file stamping, etc. You can use
the RTC app to set the RTC clock.

- The COPYSYS command described in the DRI CP/M 3 documentation is not
provided with RomWBW. The RomWBW SYSCOPY command is used instead.

- Although CP/M 3 is generally able to run CP/M 2.2 programs, this is
not universally true. This is especially true of the utility
programs included with the operating system. For example, the SUBMIT
program of CP/M 3 is completely different from the SUBMIT program of
CP/M 2.2.

Simeon Cran’s ZPM3

ZPM3 is an interesting combination of the features of both CP/M 3 and
ZCPR 3. Essentially, it has the features of and compatibility with both.

Like CP/M 3, to make ZPM3 boot disk, you put ZPMLDR.SYS on the system
tracks of the disk.

Notes

- ZPMLDR is equivalent to CPMLDR. Both are included. Previously,
ZPMLDR had issues that prevented it from properly booting RomWBW
ZPM3. However, those issues have been resolved.

- The ZPM operating system is contained in the file called CPM3.SYS
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.

FreeRTOS

Phillip Stevens has ported FreeRTOS to run under RomWBW. FreeRTOS is not
provided in the RomWBW distribution. FreeRTOS is available under the MIT
licence and further general information is available at FreeRTOS.

You can also contact Phillip for detailed information on the Z180
implementation of FreeRTOS for RomWBW. feilipu

Transferring Files

Transferring files between your modern computer and your RomWBW system
can be achieved in a variety of ways. The most common of these are
described below. All of these have a certain degree of complexity and I
encourage new users to use the available community forums to seek
assistance as needed.

Serial Port Transfers

RomWBW provides an serial file transfer program called XModem that has
been adapted to run under RomWBW hardware. The program is called XM and
is on your ROM disk as well as all of the pre-built disk images.

You can type XM by itself to get usage information. In general, you will
run XM with parameters to indicate you want to send or receive a file on
your RomWBW system. Then, you will use your modern computers terminal
program to complete the process.

The XM application generally tries to detect the hardware you are using
and adapt to it. However, you must ensure that you have a reliable
serial connection. You must also ensure that the speed of the connection
is not too fast for XModem to service. Alternatively, you can ensure
that hardware flow control is working properly.

There is an odd interaction between XModem and partner terminal programs
that can occur. Essentially, after launching XM, you must start the
protocol on your modern computer fairly quickly (usually in about 20
seconds or so). So, if you do not pick a file on your modern computer
quickly enough, you will find that the transfer completes about 16K,
then hangs. The interaction that causes this is beyond the scope of this
document.

Disk Image Transfers

It is possible to pass disk images between your RomWBW system and your
modern computer. This assumes you have an appropriate media slot on your
modern computer for the media you want to use (CF Card, SD Card, or
floppy drive).

The general process to get files from your modern computer to a RomWBW
computer is:

1. Use cpmtools on your modern computer to create a RomWBW CP/M
filesystem image.

2. Insert your RomWBW media (CF Card, SD Card, or floppy disk) in your
modern computer.

3. Use a disk imaging tool to copy the RomWBW filesystem image onto the
media.

4. Move the media back to the RomWBW computer.

This process is a little complicated, but it has the benefit of allowing
you to get a lot of files over to your RomWBW system quickly and with
little chance of corruption.

The process can be run in reverse to get files from your RomWBW computer
to a modern computer.

The exact use of these tools is a bit too much for this document, but
the tools are all included in the RomWBW distribution along with usage
documents.

Note that the build scripts for RomWBW create the default disk images
supplied with RomWBW. It is relatively easy to customize the contents of
the disk images that are part of RomWBW. This is described in more
detail in the Source\Images directory of the distribution.

FAT Filesystem Transfers

RomWBW provides a mechanism that allows it to read and write files on a
FAT formatted disk. This means that you can generally use your modern
computer to make an SD Card or CF Card with a standard FAT32 filesystem
on it, then place that media in your RomWBW computer and access the
files.

When formatting the media on your modern computer, be sure to pick the
FAT filesystem. NTFS and other filesystems will not work.

On your RomWBW computer you can use the FAT application to access the
FAT media. The FAT application allows you to read files, write files,
list a directory, and erase files on the FAT media. It can handle
subdirectories as well. It will only see 8.3 character filenames
however. Longer filenames will show up as a truncated version.

The FAT application is not on your ROM disk because it is too large to
fit. You will find it on all of the pre-built disk images as well as in
the Binary\Apps directory of the distribution.

For advanced users, it is possible to create a hybrid disk that contains
CP/M slices at the beginning and a FAT filesystem after. Such a hybrid
disk can be used to boot an operating system and still have access to
FAT files on the FAT portion of the disk. David Reese has prepared a
document describing how to do this. It is called
“SC126_How-To_No_2_Preparing_an_SD_Card_for_Use_with_SC126_Rev_1-5.pdf”
and can be found in the Doc\Contrib directory of the distribution.

Startup Command Processing

Each of the operating systems supported by RomWBW provide a mechanism to
run commands at boot. This is similar to the AUTOEXEC.BAT files from
MS-DOS.

With the exception of ZPM3, all operating systems will look for a file
called PROFILE.SUB on the system drive at boot. If it is found, it will
be processed as a standard CP/M submit file. You can read about the use
of the SUBMIT facility in the CP/M manuals included in the RomWBW
distribution. Note that the boot disk must also have a copy of
SUBMIT.EXE.

In the case of ZPM3, the file called STARTZPM.COM will be run at boot.
To customize this file, you use the ZCPR ALIAS facility. You will need
to refer to ZCPR documentation for more information on the ALIAS
facility.

Note that the automatic startup processing generally requires booting to
a disk drive. Since the ROM disk is not writable, there is no simple way
to add/edit a PROFILE.SUB file there. If you want to customize your ROM
and add a PROFILE.SUB file to the ROM Disk, it will work, but is a lot
harder than using a boot disk.

ROM Customization

The pre-built ROM images are configured for the basic capabilities of
each platform. Additionally, some of the typical add-on hardware for
each platform will be automatically detected and used. If you want to go
beyond this, RomWBW provides a very flexible configuration mechanism
based on configuration files. Creating a customized ROM requires running
a build script, but it is quite easy to do.

Essentially, the creation of a custom ROM is accomplished by updating a
small configuration file, then running a script to compile the software
and generate the custom ROM and disk images. There are build scripts for
Windows, Linux, and MacOS to accommodate virtually all users. All
required build tools (compilers, assemblers, etc.) are included in the
distribution, so it is not necessary to setup a build environment on
your computer.

The process for building a custom ROM is documented in the ReadMe.txt
file in the Source directory of the distribution.

For those who are interested in more than basic system customization,
note that all source code is provided (including the operating systems).
Modification of the source code is considered an expert level task and
is left to the reader to pursue.

Note that the ROM customization process does not apply to UNA. All UNA
customization is performed within the ROM setup script.

UNA Hardware BIOS

John Coffman has produced a new generation of hardware BIOS called UNA.
The standard RomWBW distribution includes it’s own hardware BIOS.
However, RomWBW can alternatively be constructed with UNA as the
hardware BIOS portion of the ROM. If you wish to use the UNA variant of
RomWBW, then just program your ROM with the ROM image called
“UNA_std.rom” in the Binary directory. This one image is suitable on all
of the platforms and hardware UNA supports.

UNA is customized dynamically using a ROM based setup routine and the
setup is persisted in the system NVRAM of the RTC chip. This means that
the single UNA-based ROM image can be used on most of the RetroBrew
platforms and is easily customized. UNA also supports FAT file system
access that can be used for in-situ ROM programming and loading system
images.

While John is likely to enhance UNA over time, there are currently a few
things that UNA does not support:

- Floppy Drives
- Terminal Emulation
- Zeta 1, N8, RC2014, Easy Z80, and Dyno Systems
- Some older support boards

The UNA version embedded in RomWBW is the latest production release of
UNA. RomWBW will be updated with John’s upcoming UNA release with
support for VGA3 as soon as it reaches production status.

Please refer to the UNA BIOS Firmware Page for more information on UNA.

Upgrading

Upgrading to a newer release of RomWBW is essentially just a matter of
updating the ROM chip in your system. If you have spare ROM chips for
your system and a ROM programmer, it is always safest to retain your
existing, working ROM chip and program a new one with the new firmware.
If the new one fails to boot, you can easily return to the known working
ROM.

Prior to attempting to reprogram your actual ROM chip, you may wish to
“try” the upgrade. With RomWBW, you can upload a new system image
executable and load it from the command line. For each ROM image file
(.rom) in the Binary directory, you will also find a corresponding
application file (.com). For example, for SBC_std.rom, there is also an
SBC_std.com file. You can upload the .com file to your system using
XModem, then simply run the .com file. You will see your system go
through the normal startup process just like it was started from ROM.
However, your ROM has not been updated and the next time you boot your
system, it will revert to the system image contained in ROM.

Upgrading via Flash Utility

If you do not have easy access to a ROM programmer, it is usually
possible to reprogram your system ROM using the FLASH utility from Will
Sowerbutts. This application, called FLASH.COM, can be found on the ROM
drive of any running system. In this case, you would need to transfer
the new ROM image (.rom) over to your system using XModem (or one of the
other mechanisms described in the Transferring Files section). The ROM
image is too large to fit on your RAM drive, so you will need to
transfer it to a larger storage drive. Once the ROM image is on your
system, you can use the FLASH application to update your ROM. The
following is a typical example of transferring ROM image using XModem
and flashing the chip in-situ.

E>xm r rom.rom

XMODEM v12.5 - 07/13/86
RBC, 28-Aug-2019 [WBW], ASCI

Receiving: E0:ROM.IMG
7312k available for uploads
File open - ready to receive
To cancel: Ctrl-X, pause, Ctrl-X

Thanks for the upload

E>flash write rom.rom
FLASH4 by Will Sowerbutts <will@sowerbutts.com> version 1.2.3

Using RomWBW (v2.6+) bank switching.
Flash memory chip ID is 0xBFB7: 39F040
Flash memory has 128 sectors of 4096 bytes, total 512KB
Write complete: Reprogrammed 2/128 sectors.
Verify (128 sectors) complete: OK!

Obviously, there is some risk to this approach since any issues with the
programming or ROM image could result in a non-functional system.

To confirm your ROM chip has been successfully updated, restart your
system and boot an operating system from ROM. Do not boot from a disk
device yet. Review the boot messages to see if any issues have occurred.

Upgrading via XModem Flash Updater

Similar to using the Flash utility, the system ROM can be updated or
upgraded through the ROM based updater utility. This works by by
reprogrammed the flash ROM as the file is being transfered.

This has the advantage that secondary storage is not required to hold
the new image.

From the Boot Loader menu select X (Xmodem Flash Updater) and then U
(Begin Update). Then initiate the Xmodem transfer of the .img or .upd
file.

More information can be found in the ROM Applications document.

Post Update System Image and Application update process

Once you are satisfied that the ROM is working well, you will need to
update the system images and RomWBW custom applications on your disk
drives. The system images and custom applications are matched to the
RomWBW ROM firmware in use. If you attempt to boot a disk or run
applications that have not been updated to match the current ROM
firmware, you are likely to have odd problems.

The simplest way to update your disk media is to just use your modern
computer to overwrite the entire media with the latest disk image of
your choice. This process is described below in the Disk Images section.
If you wish to update existing disk media in your system, you need to
perform the following steps.

If the disk is bootable, you need to update the system image on the disk
using the procedure described below corresponsing to the operating
system on your disk.

- CP/M 2.2

Boot to CP/M 2.2 from ROM, then use SYSCOPY to update the system
image on all CP/M 2.2 boot disks/slices. The CP/M 2.2 system image
is called CPM.SYS and is found on the ROM disk. For example:

B>SYSCOPY C:=CPM.SYS

- ZSDOS

Boot to Z-System from ROM, then use SYSCOPY to update the system
image on all ZSDOS boot disks/slices. The ZSDOS system image is
called ZSYS.SYS and is found on the ROM disk. For example:

B>SYSCOPY C:=ZSYS.SYS

- NZCOM

NZCOM runs on top of either CP/M 2.2 or ZSDOS. By default, the
RomWBW disk image for NZCOM uses ZSDOS. Follow the corresponding
procedure above to update the system image on the NZCOM boot
disks/slices.

- CP/M 3

CP/M 3 uses a multi-step boot process involving multiple files. The
CP/M 3 boot files are not included on the ROM disk due to space
constraints. You will need to transfer the files to your system from
the RomWBW distribution directory Binary\CPM3.

After this is done, you will need to use SYSCOPY to place the CP/M 3
loader image on the boot tracks of all CP/M 3 boot disks/slices. The
loader image is called CPMLDR.SYS. You must then copy (at a minimum)
CPM3.SYS and CCP.COM onto the disk/slice. Assuming you copied the
CP/M 3 boot files onto your RAM disk at A:, you would use:

A>B:SYSCOPY C:=CPMLDR.SYS
A>B:COPY CPM3.SYS C:
A>B:COPY CCP.COM C:

- ZPM3

ZPM3 uses a multi-step boot process involving multiple files. The
ZPM3 boot files are not included on the ROM disk due to space
constraints. You will need to transfer the files to your system from
the RomWBW distribution directory Binary\ZPM3.

After this is done, you will need to use SYSCOPY to place the ZPM3
loader image on the boot tracks of all ZPM3 boot disks/slices. The
loader image is called CPMLDR.SYS. You must then copy (at a minimum)
CPM3.SYS, ZCCP.COM, ZINSTAL.ZPM, and STARTZPM.COM onto the
disk/slice. Assuming you copied the ZPM3 boot files onto your RAM
disk at A:, you would use:

A>B:SYSCOPY C:=CPMLDR.SYS
A>B:COPY CPM3.SYS C:
A>B:COPY ZCCP.COM C:
A>B:COPY ZINSTAL.ZPM C:
A>B:COPY STARTZPM.COM C:

You may be wondering if the references to CPMLDR.SYS and CPM3.SYS
are typos. They are not. ZPM3 uses the same loader image as CPM3.
The ZPM3 main system code file is called CPM3.SYS which is the same
name as CP/M 3 uses, but the file contents are not the same.

Finally, if you have copies of any of the RomWBW custom applications on
your hard disk, you need to update them with the latest copies. The
following applications are found on your ROM disk. Use COPY to copy them
over any older versions of the app on your disk:

- ASSIGN.COM
- SYSCOPY.COM
- MODE.COM
- FDU.COM (was FDTST.COM)
- FORMAT.COM
- XM.COM
- FLASH.COM
- FDISK80.COM
- TALK.COM
- RTC.COM
- TIMER.COM
- INTTEST.COM

For example: B>COPY ASSIGN.COM C:

Some RomWBW custom applications are too large to fit on the ROM disk. If
you are using any of these you will need to transfer them to your system
and then update all copies. These applications are found in the
Binary\Apps directory of the distribution and in all of the disk images.

- FAT.COM
- TUNE.COM

System Update

If the system running ROMWBW utilizes the SST39SF040 Flash chip then it
is possible to do a System Update in place of a System Upgrade in some
cases.

A System Update would involve only updating the BIOS, ROM applications
and CP/M system.

A System Update may be more favorable than a System Upgrade in cases
such as:

- Overwriting of the ROM drive is not desired.
- Space is unavailable to hold a full ROMWBW ROM.
- To mimimize time taken to transfer and flash a full ROM.
- Configuration changes are only minor and do not impact disk
applications.

The ROMWBW build process generates a system upgrade file along with the
normal ROM image and can be identified by the extension “.upd”. It will
be 128Kb in size. In comparison the normal ROM image will have the
extension “.rom” and be 512Kb or 1024Kb in size.

Transferring and flashing the System Update is accomplished in the same
manner as described above in Upgrading with the required difference
being that the flash application needs to be directed to complete a
partial flash using the /p command line switch.

E>flash write rom.upd /p

RomWBW Distribution

All source code and distributions are maintained on GitHub. Code
contributions are very welcome.

RomWBW GitHub Repository

Distribution Directory Layout

The RomWBW distribution is a compressed zip archive file organized in a
set of directories. Each of these directories has it’s own ReadMe.txt
file describing the contents in detail. In summary, these directories
are:

--------------------------------------------------------------------------
Application Description
------------- ------------------------------------------------------------
Binary The final output files of the build process are placed here.
Most importantly, are the ROM images with the file names
ending in “.rom”.

Doc Contains various detailed documentation including the
operating systems, RomWBW architecture, etc.

Source Contains the source code files used to build the software
and ROM images.

Tools Contains the MS Windows programs that are used by the build
process or that may be useful in setting up your system.
--------------------------------------------------------------------------

Acknowledgments

While I have heavily modified much of the code, I want to acknowledge
that much of the work is derived from the work of others in the
RetroBrew Computers Community including Andrew Lynch, Dan Werner, Max
Scane, David Giles, John Coffman, and probably many others I am not
clearly aware of (let me know if I omitted someone!).

I especially want to credit Douglas Goodall for contributing code, time,
testing, and advice. He created an entire suite of application programs
to enhance the use of RomWBW. However, he is looking for someone to
continue the maintenance of these applications and they have become
unusable due to changes within RomWBW. As of RomWBW 2.6, these
applications are no longer provided.

- David Giles contributed support for the CSIO support in the SD Card
driver.
- Ed Brindley contributed some of the code that supports the RC2014
platform.
- Phil Summers contributed Forth and BASIC in ROM, the AY-3-8910 sound
driver as well as a long list of general code enhancements.
- Phillip Stevens contributed support for FreeRTOS.
- Curt Mayer contributed the Linux / MacOS build process.
- UNA BIOS and FDISK80 are the products of John Coffman.
- FLASH4 is a product of Will Sowerbutts.
- CLRDIR is a product of Max Scane.
- Tasty Basic is a product of Dimitri Theulings.
- Dean Netherton contributed the sound driver interface and the
SN76489 sound driver.
- The RomWBW Disk Catalog document was produced by Mykl Orders.

Contributions of all kinds to RomWBW are very welcome.

Getting Assistance

The best way to get assistance with RomWBW or any aspect of the
RetroBrew Computers projects is via the community forums:

- RetroBrew Computers Forum
- RC2014 Google Group
- retro-comp Google Group

Submission of issues and bugs are welcome at the RomWBW GitHub
Repository.

Also feel free to email Wayne Warthen at wwarthen@gmail.com.