Over the last couple I’ve been working on a new version of the GD-77 CPS, to add several new features, and as there are currently problems with the Contacts download system from Ham-digital.org, I thought I should post this update which adds a feature requested by “mike” in a comment to my previous post, where he could use a different URL to download the data
This beta version also includes an early version of the new Calibration screen, which currently only allows calibration data to be viewed, but not updated.
As usual the ‘development’ version installers can be downloaded from github
https://github.com/rogerclarkmelbourne/radioddity_gd-77_cps2.0.5/tree/development/installer
The first change is the addition of the Extras menu from the main menu bar. This makes it easier to get to the new features. For example the “Download contacts” feature can be accessed here rather than needing to open the Digital Contacts screen and press the Internet Download button.
The other 2 options on this menu are the Calibration viewer and the DMR ID screens.
Currently the Calibration screen only allows viewing of the calibration data. This is because Jason VK7ZJA has not finished his exploration of how the GD-77 stores its calibration data in its “flash” memory chip. So the sections and values shown on this screen are not guaranteed to be correct.
There are also some less than ideal operational features with my current implementation of the Calibration download. Specifically its not possible to cancel it.
So that the CPS can read the calibration data you need to put the GD-77 into Memory Access Mode.
This is a hidden feature which was discovered by Colin G4EML, and appears to be in all firmware versions, from 2.6.6 (and possibly even before)
To enter this mode, a key sequence similar to the DMR ID (ActiveClient) needs to be held down whilst turning on the GD-77.
The keys required for this mode are SK2 (the lower / blue coloured) button on the side of the radio.
The green menu key and the * (star) key
If you have enabled this feature correctly, the CPS will be able to download the 64k page, of memory which contains the few hundred bytes of calibration data.
Note. If you have not correctly enabled this mode, the GD-77 sends back zeros (0x00 hex) for the entire 64k page, and the CPS checks for zeros and displays a message and does not open the Calibration Viewer screen
The Calibration Viewer has 2 tabs, one for VHF and one for UHF. The only difference between whats on these 2 tabs, is that there are less power calibration points on VHF than UHF.
This is because the GD-77 uses 5Mhz wide calibration points, and the UHF band is wider than the VHF band.
The other difference is of course the actual calibration values.
On the Download Contacts, I have made a small change, which was suggested by “Mike” in a comment to my post about the Ham-digital data feed not working correctly at the moment.
Mike wanted to use his own custom PHP download script, but the screen would not allow the URL to be changed
So I updated the screen to allow people to specify their own download URL.
I have also been working on a method to import the contacts list data directly from DMR MARC, however although I have got this feature working, I have not included it in this release because the DMR MARC servers seem to be overloaded for 90% of the time and the data is not available.
Also, even after filtering by Region prefix code, there are usually thousands of DMR ID’s available to import and the GD-77 can only hold 1024 including Talk Groups.
So I am delaying releasing this addition until I find a better way to handle their server outages and also how to integrate this with the DMR ID database (see below)
DMR ID screen
The DMR ID screen, is only in the early stages of development. My thought at the moment is that the DMR ID database will act as an extension to the Contacts data, because its better to have the DMR ID’s stored in the Digital Contacts, as this shows both Callsign and Name on the GD-77 screen. However entries in the DMR ID database only have storage for 8 characters, which effectively limits the GD-77 to only display the callsign.
Just to make matters more confusing, the GD-77 has a firmware bug, so that it uses the DMR ID database before it uses the Digital contacts, to lookup the station details from the ID code. So if you have the same ID in both the Digital Contacts and the DMR ID data, you only see the callsign 
Integrating the DMR ID database as an extension to the Digital Contacts is not a trivial piece of programming, so keeps getting put to the bottom of my To Do list, because there are always more important things that I need to spend time on.