Check it. It is in the previous post.
If you know Gio I have made firmwares with Russian language support for edge 705 and 72H. (firmwares 3.10 and 2.30) I have posted them in gps-forum.ru. Now still guys from Russia, Ukraine etc write to me emails about the newer versions of the firmwares for those models. In fact I learnt how to add new languages to the old garmin units from neadrenalin (Andrew e-trex.narod.ru). I didn't make it my self. I just wanted to learn how to add Bulgarian after I read in gps-forum.ru his cyrrilizied firmwares for GPSMAP 60CSX. That is all. BTW many thanks neadrenalin for his kind help, patience and support for helping me!
My point is that with Russian, Bulgarian and other Cyrrilic based languages the task is a little bit more difficult than with the Latin languages. Because two more additional changes should be made in the firmware than just adding the new language text - new cyrrilic fonts should be added and the table corresponding to the supported letters should be modified too. I have successfully make it on Vista HCX firmware, GPSMAP 60CSX and etrex Summit/Venture HC firmwares with adding Bulgarian. Adding cyrrilic fonts and text is easy but I am not sure about modifying the letters table. I may try but I need help from someone more experienced than me.