Yesterday, I modified my decompiler for the guiResData.hex file to get a readable result.
I do not know, if there is a full description of the format of this file somewhere?
In short, the file consists of four large blocks:
1) Menu
2) six fonts
3) Table of text strings (for menus).
4) help
You can see the menu in the attached file.
Fonts have a binary format (the same as for fonts, compiled in elf). The fonts are completely raster, no truetype or vectors.
Text strings do not have independent meaning, they are used only in the menu.
The help is only in two languages, each language includes two blocks - a reference table and text strings. The format of the tables I have not yet understood (and do not plan).