OpenGD77 is an open source (GNU General Public Licence Version 2)
and is a great effort on the part of Rodger Clark, VK3KYY, in Melbourne and his
co-authors. Rodger Clark is a Freelance IT Consultant & Developer, based in Melbourne Australia and
is a legend in DMR firmware, modifications, and the DMR mode. It is the opinion of man
that this firmware is far superior to the manufactures. I am certaintly, of that
opinion.
Rodger's web site is DISCONTINUED:
https://www.rogerclark.net/
The User Forum is NO LONGER AVAILABLE:
http://www.opengd77.com/index.php
It is the opinion of many that this firmware is far superior to the manufactures
firmware.
The github repository OBSOLETE :
Development of OpenGD77 appears to have resumed, with firmware and code being released at
https://www.opengd77.com/downloads/.
The authors have unfortunately chosen not to publish the new code on GitHub.
The sole purpose of the GITHUB repository is therefore to preserve the code.
NOTE: This github repository is out of date.
https://github.com/open-ham/OpenGD77
There is some information here but it too seems out-of-date.
OpenGD77 - Amateur radio firmware for the GD-77, GD-77S, DM-1801, DM-1801A, RD-5R,
MD-9600/RT-90, MD-UV380/RT-3S, DM-1701/RT-84 and MD2017/RT-82 radios:
https://www.opengd77.com/archive/index.html
The best information I can find in August 2025 is here:
Index of /downloads/PC_CPS/Latest/:
https://www.opengd77.com/downloads/PC_CPS/Latest/
I downloaded https://www.opengd77.com/downloads/PC_CPS/Latest/OpenGD77CPSInstaller_R2025.03.23.01.exe and installed on Windows 10. Note that links from the index page simply hang and do not link when selected, so explicity select the download page.
[Top][Home]Install the latest CPS application, available https://www.opengd77.com/downloads/PC_CPS/Latest/OpenGD77CPSInstaller_R2025.03.23.01.exe
Unzip the downloaded archive, Copy the file GD-77_V4.3.9.sgl that is located in the sub directory Firmware software V4.3.9 to a known location. This file will be used the each time you flash a OpenGD77 firmware file.
Note the Callsign is blank and the DMR ID is a nonsence as the OpenGD77
CPS will not allow it to be blank.
[Top][Home]
The Codeplug comes with marine VHF and CB UHF frequencies.
As we know, the marine and citizen band channels are outside the amateur radio bands
As a resukt they are enabled to receive only. If you try to tramsmit on these frequencies
you will get an error message:
ERROR - Out of Band
To enable out of band transmitting do the following:
Note The use of the VHF Marine Bands requires operators to hold a minimium of a
SHORT RANGE OPERATOR CERTIFICATE OF PROFICIENCY (SROCP)
Australian Maratine College's SROCP:
https://www.amc.edu.au/industry/omc/certificates/short-range-operator-certificate-of-proficiency-srocp
Note thes are software controlled band limits, and this is a separate issue to
the hardware band constraints. The RF hardware can't technically operate reliably
outside these bands.
Note that, the OpenGD77 community and documentation often refer to the SK and TK keys, other times to
the Black, Blue, Orange, and Green and Red keys. This table may help decipher the instructions.
| Button | Position | Colour | Short press | Long press |
|---|---|---|---|---|
| SK1 | 1st one under the PTT | Black | Menu | Nothing programmed yet |
| SK2 | 2nd one under the PTT | Blue | Channel info | Channel info |
| TK | Top button next to antenna | Orange | High/low power select | Long press = Scan On/off |
| Menu | Left-hand button under the screen | Green | Menu | |
| Exit | Right-hand button under the screen | Red | Exit or Back |
