Radio Service Software
Most, if not all, Motorola
2-way radios can be programmed by means of a
dedicated purpose-written piece of software, called Radio Service Software
or RSS for short. Every type of radio, and sometime even every individual
model, requires its own RSS. This page deals with programming a standard
SABER I, II or III hand-held radio.
It allows channels to be assigned with a frequency, output power,
CTCSS and many other features that the radio is capable of.
As the SABER radios
were developed in the late 1980s, it should
be noted that the RSS was also developed in that era. As a result, it
won't run on a modern Windows-based computer. Please read this page
carefully before attempting to program the radio. In particular
read the warning below.
Furthermore, you should get yourself a copy of the RSS User's Guide ,
as the software is not self-explanatory and most of the options have
a rather cryptic desciption. The User's Guide gives a detailed explanation
of each of the options and comes with a number of examples.
The configuration data of a SABER radio, is called a codeplug.
A codeplug defines the features of the radio, but also the channels and
their properties (e.g. CTCSS).
The RSS allows codeplugs to be read from a radio, store them to disc,
modify them, and write them back to the radio.
Before attempting to write a configuration to a radio, it would be wise
to read the current status of the radio first, and store this codeplug
on your harddisc. If something goes wrong when programming the radio,
you can use this 'golden' codeplug to restore your precious radio.
Also, before you start, make sure you read and understand the RSS User's
Please note that the SABER RSS can not run on a Windows-based computer
or anything that is faster than, say, 50 MHz, not even when running it
in the DOS shell. The software was written in the late 1980s and contains
timing loops that are based on the speed of a PC of that era. Faster
computers will attempt to write the data at a higher rate, resulting
in corrupted radios. Although this sounds serious, it is possible to recover
such radios once the data rate is correct again.
In order to program a SABER radio, the following is required:
- Old 386 PC with DOS
This is probably the most difficult-to-find part. As the RSS software was written
many years ago (when Windows and faster processors were not yet available),
the software uses built-in timing loops that are processor speed-dependent.
As a result the RSS can only be used on an old PC with a 386 processor that
runs no faster than 50MHz and has no cache (or that has it cache disabled).
Any attempt to use a faster PC will corrupt your radio.
- Radio Interface Box (RIB)
A small interface box is needed between the radio (programming cable) and
the PC. It converts the 2-wire serial data and levels into bi-directional
data stream, suitable for connection to the COM port of a PC.
Most RIBs are suitable for nearly all Motorola radios.
- Programming cable
A special interface cable is needed for virtually every type of radio ever
made by Motorola. Such cables have a special motorola accessory plug at one end
and a 25-way D-type (parallel) connector at the other end, suitable for
connection to the RIB (see below).
- Radio Service Software (RSS)
For each different radio, Motorola developed a dedicated RSS that can not be
used on other radios. Please note that the MX-1000 (a European variant
of the SABER) requires a different version of the RSS. The RSS is no
longer available from Motorola, but copyright restrictions prevent it from being
distributed freely. All we can suggest is to do a
Please do not ask us for a copy of this software.
Part number RVN4002K (latest version: 07.01.00, released 13 December 1995).
- RSS Manual
For the Radio Service Software (RSS) a comprehensive manual is available
from Motorola. Without this manual is is very difficult to understand
the many options that can be programmed with the sofware, as most of them
are rather cryptical. Get a copy of the RSS Manual for the Saber series of
radios and read it thoroughly before starting to the the RSS.
When programming a SABER radio using the Radio Service Software (RSS),
it is important to realize that the RSS was developed many years ago,
in the days that Windows™ did not yet exist.
In fact, the software was developed at a time when processors did not
exceed the 50 MHz limit.
As the software contains many timing loops that are dependent on the
speed of the processor, it is important that your computer is
slow enough to handle this. Furthermore, the software was written
for DOS and does not run happily under Windows, even not when run inside
a DOS shell.
For the best results, find an old 386 or 486-based computer (preferrably
a laptop) with a processor speed of, say, 33 MHz and turn off its
cache (when present) in the BIOS settings. If possible, set the
processor speed to SLOW. This will prevent any errors when programming.
The advantage of using a laptop is that it is compact, has a built-in
screen and generally has a suitable 9-pin RS-232 interface to which
the RIB can be connected. A good example of a suitable laptop
is the Toshiba T-1910-120 shown above. As most computers from this
era do not have a built-in network interface, the only way to install
the RSS on it, is via the floppy drive at the front.
Radio Interface Box (RIB)
As the serial data interface of the radio differs from the RS-232
port of the PC, a small converter box, known as the Radio Interface
Box, or RIB, should be used. It connects to the computer via a
standard DE9 RS232 cable and has a 25-way D-type socket
for connection to the radio.
The interface converts the uni-directional radio interface into
a bi-directional one that is needed for the computer. Furthermore,
it converts the data signals to the required levels.
Most RIBs are powered by an internal 9V battery, but can
also be powered externally from a mains adapter.
As an original Motorola RIB may be hard to find and will come at
a price, you might need to find an alternative.
Although it is perfectly possible to build your own RIB (see below),
good quality RIBs from alternative manufacturers can often be
found on auction sites like Ebay for $30 or less.
When buying a RIB, ensure that it is compatible with the
Motorola RLN4008. It is suitable for nearly all Motrola radios.
The image above shows an original Motorola RIB (left) aside
a clone from an alternative manufacturer (right).
The original RIB has a 15-way D-type socket (DA15) for connection
to the computer's COM port, whilst the clone has a more
common 9-way D-type socket for this, allowing a standard
9-to-9 pin RS232 cable to be used. Both RIB-variants have a
25-way socket for connection to the radio,
using a suitable programming cable (see below).
As nearly each type of Motorola radio has its own specific programming
interface, you need to find a suitable cable between the RIB
and the radio; in this case the SABER. On most radios,
the programming interface is part of the accessory expansion connector
at the rear of the radio.
On the SABER, the accessory socket is at the rear of the radio,
close to the antenna. It consists of a number of flat-faced circular
contact pads that are integrated with the plastic case.
It is often used for an external speaker/microphone.
On some (new) radios this socket is protected by a
removable plastic lid
that is held in place with a single cross-head or safety-hex screw.
The required SABER programming cable used to be available from Motorola,
but is no longer being manufactured. Luckily, good quality copies
are available from auction sites such as Ebay.
Radio Service Software (RSS)
For programming frequencies and (optional) features into the radio,
Motorola developed the so-called Radio Service Software (RSS).
The RSS allowed many hidden features inside the radio to be
enabled or disabled. Note that a different RSS is needed for each
different type of Motorola radio.
For programming the SABER series radios, the SABER RSS is needed.
Please note that this RSS is not compatible with the
SYSTEMS SABER RSS nor with the ASTRO SABER RSS. Furthermore,
the European version of the SABER (MX-1000) needs the
MX-1000 RSS. Other versions will simply not work and will generate
an error when trying.
If want to use the RSS to program the Amateur Radio Frequencies
(144-146 MHz and 430-440 MHz) you may need to patch the RSS first.
In order to modify the RSS for out-of-band frequencies,
follow the guidelines below.
Please note that the RSS for the SABER series radios is no longer
available from the manufacturer Motorola. Nevertheless, the copyright
restrictions remain in effect, preventing the software from being
distributed freely. All we can suggest is to do a
In any case do not ask us for a copy of this software – not even for
amateur use – as we don't want to break any laws.
The RSS is written in such a way, that most of the options can only
be programmed by an experienced user or service technician. Whilst
using the software is pretty straightforward, the options are not
exactly intuitive and the built-in help files are not particular
helpful at all.
Luckily, Motorola has written an extensive and clear manual for the
SABER RSS. It describes the use of the software in a clear way
and gives detailed information and examples of the many options
that can be programmed with the RSS.
The software has part number RVN4002K and the manual can usually
be found by doing a simple
If you find the manual, please download it and read it carefully
before attempting to use the software. Make sure that you understand
the many functions and options before you start. It will avoid
Follow the instructions for setting up the software and connecting
the radio carefully. Once the PC and software have been set up correctly,
and the radio is connected - via the RIB - to the computer, you should
first try to read the current configuration of the radio.
Such a complete configuration is called a CODEPLUG by Motorola.
It contains the frequencies that are assigned to the channels, plus
the many options, such as CTCSS (PL), high-low power, encryption, etc.
In some countries, such as Denmark, Germany, The Netherlands and
the Scandinavian countries, a special version of the SABER, known
as the MX-1000 series was available from a variety of operators.
The MX-1000, 2000 and 3000 are analog to the
SABER I, II and III.
Although the MX-series is cosmetically similar to the SABER,
it has a different set of features and specifications.
It can only be programmed with a dedicated MX-1000 RSS.
SABER radios have two types of processors. The main one is CORE
(Control Of Radio Electronics). It is the actual microcontroller of the
SABER's mother board. The firmware inside the CORE is mask-programmed and
can not be changed without swapping the processor. Different versions of the
CORE support different features. Generally speaking, the higher the CORE version
the more features the radio supports. One of the most common versions of CORE
is 5D. Certain features of the radio are only available on later versions
of CORE, like 6D and 8D. All SABERs have a CORE.
The second type of processor is COPE (Control of Peripheral Electronics).
It is used for the display, the keyboard and an additional number of channels
As such, COPE is only available in a SABER II
and SABER III. Radios without
a display (i.e. a SABER I or IE)
do not have a COPE processor.
The COPE is part of the front assembly of the SABER II and III.
There are two different (hardware) implementations of the COPE board
of a SABER II:
one with 2KB of memory and one with 8KB of memory. The difference can be
determined by counting the number of chips on the COPE board. The 8KB version
contains 5 chips, whilst the 2KB one has only 4 of them.
The 5th chip is the DTMF tone encoder.
When something goes wrong whilst programming a SABER, an error message
may appear on the display (SABER II and III only). In such cases, the
display shows ERR followed by three digits. The first digit identifies
the hardware that causes the error. It can take three values (see below):
The remaining two digits are the hexadecimal notation of a 8-bit word (byte)
in which each bit represents a single error (flag). This way, multiple errors
can be reported simultaneously. The bits can be written out in the
following 8-bit mask, with the bit value written above it:
For example: error message ERR 1 0B means that the COPE processor has
raised the error 0B (hexadecimal notation of 11). This means that three
errors are present in the blue section above (8 + 2 + 1).
Please note that error ERR 1 0D always appears on the display when
programming the radio. This is normal. Once programming has completed,
the display should return to normal.
When programming a SABER for the 2m amateur band, one needs to be able
to enter frequencies in the range 144 to 146 MHz (US: 144 to 148 MHz).
By default, this is only possible on radios that work in the 136-150.8 MHz
band-split (i.e. the Government Split). There are three further band-splits
that are suitable for the HAM frequencies:
- 146-162 MHz
- 146-174 MHz
- 148-174 MHz
Although radios in this band-split are perfectly capable of transmitting
and receiving on the amateur frequencies, you can not enter the required
frequencies, as the RSS is bound to the lower limit (146 or 148 MHz).
This problem can be solved by patching the RSS program. A good description
of how to patch the RSS can be found
This is basically how it works:
Look for the EXE-file (e.g. 'SABER.EXE'), which resides inside the directory
that holds the RSS. Inside this file, which consist of compiled code,
are the limits of the band-splits, stored as 32-bit values (i.e. 4 bytes
By looking for these 32-bit values, and replacing them by an alternative
one, the software can be tricked into believing that the lower limit
is 144 MHz. This can be done either with a piece of home-built software,
or with a suitable HEX-editor. In the latter case, you have to look for
the hexadecimal representation of the required values (146000000 and
148000000) and replace them with
the hexadecimal value of the alternative (144000000).
New lower limit
The same can be done for the UHF band. The frequency range (split) that
is the most useful one for the 70cm amateur band, is the 440-470 MHz one.
Although it has been reported that US version of the SABER can be made
to run as low as 438 MHz (but not lower), some international versions
of the MX-1000 cover the entire amateur band without any problems.
The only problem is that the (old) MX-1000 RSS will not allow frequencies
below 440 MHz to be entered. So, we have to apply the same trick:
replace the lower VHF limit (440000000) by 430000000:
New lower limit
Please note that the notation of 32-bit hexadecimal values may differ
between processors. Typical processors, like an Intel x86, store a 32-bit
value in the so-called big-endian order, whilst other processors, such as
ARM, store their value in little endian order. In the latter case the
order of the 4 bytes that form the 32-bit value, are reversed.
The values are not word-aligned.
Big endian (e.g. Intel)
Little endian (e.g. ARM)
The RSS can also be used to align the radio,
which might be necessary if you have swapped one or more modules, or if
you are trying to convert a radio to a different band-split.
Please note that there are no adjustments inside the radio itself.
All alignments are done in software with the RSS.
In order to align a SABER radio, it needs to be connected to a special
test set that takes over the connections to the antenna, the microphone
and the speaker, and control certain features.
Motorola service engineers used the Portable Radio Test Set RTX4005B for
this, in combination with the RTK4203C programming and test cable.
The complete test set is shown in the image on the right. The test set
can control features like push-to-talk (PTT) and private-line (PL), and has
sockets for the connection of an external multi-meter that can be used
for accurate alignment.
Unfortunately, the RTX4005B test set is rather expensive and difficult to
find. And the price of an RTK4203C programming cable is totally absurd
(US$ 349) if it can be found at all. Luckily, it is possible to use a test
set from a different brand, or to build a suitable break-out box yourself.
An example of such a break-out box is shown in the image on the right.
We built it especially for aligning the SABERs in our collection
and it has performed very well. It only needs a single connection to
the SABER's universal socket.
The RF output (antenna) is available on a BNC socket, whilst the audio
in and outputs are available on two RCA sockets (cinch).
All pins of the universal connector
are also available on a 15-way
D-type socket at the side of the box, which allows us to simultaneously
connect the radio to the PC (and hence the RSS software).
A built-in speaker is
used for monitoring the receiver's audio.
At the center is a large red PTT button and at the top left is
a three-position switch to alter the voltage at pin 7 of the universal
connector (OPT SEL). For alignment, it should be set to 2.5V.
More details in the photographs.
Control of Radio Electronics
The software (firmware) of the main controller inside the SABER radio.
It can be regarded as the main firmware of the radio and controls all
features, alignments, assignments, etc.
Control of Peripheral Electronics
This is a secundary system (subsystem) which is only present on a
SABER II (MX2000) and SABER III (MX3000). COPE is the firmware of the
microcontroller that is mounted behind the front panel. It consists
of an internal and an external part. It controls the user interface,
the display, DTMF, etc.
Radio Interface Box
Radio Service Software
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© Crypto Museum. Created: Thursday 14 March 2013. Last changed: Monday, 21 June 2021 - 16:19 CET.