If you are thinking about buying one, or have one but haven't programmed it through your PC, it can get messy.
To program a PX-777 from PC you need four things. A PC, a PX-777, a programming cable and some software. Your PC will need to be able to run windows programs. I haven't tried wine. I suspect that 98/Me will work OK - I plan to try it later just for the hell of it. Under Windows XP you might have problems but it can be fixed. If you are using Vista then you can fix that by upgrading to Windows XP.
The programming cable can be purchased online. You can (apparently) also use cables designed for Kenwood handhelds. As a ham you might want to make your own. It's not that difficult. If you have a standard RS-232 serial port then you need to convert to TTL level signals with a MAX232, MAX 233 or similar. There's a hand drawn circuit here. Make sure the lead to the radio is as short as possible. Although this signal is usually called "TTL RS232", it is not really RS232 and there will be signal loss over long cables. It will also be prone to interference.
Serial ports aren't that common any more, so you might have a USB converter or want to buy one. You need to establish what comm port it becomes, and you will find that the port number might change from PC to PC and even from USB port to USB port! Open the device manager and select the PORTS item. Look for your port there. The next problem is that some of the software allows you to select only comm port 1,2,3 or 4. (USB adaptors usually end up being comm 5 or higher). This is very poor programming. You can get around that by reassigning the comm port of your device. As administrator, right click on the port in device manager, select Properties, click the Port Settings tab, select the Advanced button, and use the dropdown to select a new port. Hopefully you will find one of the first four free. After you close all the windows you just opened, you might need to unplug the device and replug to gain access to the new port.
Another option which is easier than making a MAX232 interface is to buy a USB to TTL converter. I bought a Sparkfun adaptor for $AUD 17 in Perth. Shops that sell Arduino or robotics might carry these. Also look here. This adaptor has a USB mini-B socket one end and a six pin SIL socket the other end. An A-to-mini-B USB lead is required, such as used on most USB hard drives, some media gadgets and some phones. The SIL connector is standard 2.54mm pitch and has TX, RX, GND, +5V and two handshake signals. Connect the GND, TX and RX the same way as in the diagram mentioned above. Keep the wires short! I bought a 3.5mm stereo plug and 2.5mm stereo plug from an electronics store and used some shielded twin cable connect it together. Did I mention short wires?
As for the software... well Puxing make great radios. If you look here, you will find some programming software. See if you can work out which one to download. Yes, it is (as of this writing) "V6". If you use windows XP or any of the other NT versions and are like me then you log into the OS as a regular user (limited account) and not as an administrator. If you do the latter then suffer! The problem with some programmers is that they aren't really programmers. They just write programs. And usually while they are logged in as an administrator. They never test their software as a user. If they did, they would see that they make the same old mistake time and time again. Save files in the application install directory. Why is this stupid? Well you can't write into install directories if they are in a system directory unless you have rights. Eg admin rights. Files like settings and other user stuff are supposed to go in the user's home folderer, preferably in the application data folder which is what it's there for. This also means you can have multiple users on one PC without each stomping on the others' settings. But no, the Fuxing software tries to save settings in "C:\Program Files\PX6IN1\" which it can't do as a user, so the software is stuck with the default settings. If you have a PX-777+, the default setting is to use Chinese language.
How to get around this? Well you can install the application to a folder that anyone can read and write, or you can install the default directory and then copy the whole folder somewhere else. I chose the latter.
1) Install the software as normal (as admin of course).
2) Look at "C:\Program Files\PX6IN1". Copy the PX6IN1 directory to a USB thumb drive or your 'My Documents' folder or some other location you have rights to. 'Shared Documents' is another good place. This is where I keep all unfriendly applications. There's plenty of them.
3) Uninstalll the software. You have a copy remember?
4) Run application from thumb drive. Hey presto, language is now English. The application has the default MFC icon (blue, cyan and white). They could even be bothered to install their trade icon in the application.
When you run the application, select "PX777/328 CH128 +2TONE" for the PX777+. That will be remembered for next time you run it. Next, make sure you set the comm port - Click on the "Port" menu. It defaults to port 1 and is NOT remembered for next time. Jeez. Next, click on the "Program" menu adnd select "Read from radio." Click on the Start button. If that works immediately then you are ready to roll. If it doesn't work then you will need to check that your cable is correct and that you have selected the correct port. Also make sure you have selected the correct model of radio... it probably won't work even if everything else is OK.