Here is S-1942 (S-42) which is used in Czech Republic and Slovak Republic (Europe). It might also be used in other Central & Eastern Europe countries. It is the system developed for and used by Warsaw Treaty military block (not existing any more). It might still be used by Czech army, I do not know. Our touristic 1:50000 maps are based on military maps that were top secret till the collapse of communistic empire in 1989 and use S-1942. Some of new 1:100000 and 1:200000 maps use WGS 84. S-1942 (S-42) uses Krasovski's elipsoid and the grid is based on Gauss-Kruger projection, 3rd belt (stripe) (E12°-E18°). I do not understand what that means. This information comes from User Guide Add On by local (Czech) distributor. I checked the user setup (provided by them) with two different maps and it seems to work fine (on G12XL). Setup for G12XL: ------------------------------- Map datum (Krasovski's elipsoid) ----------- dx: 23 dy: -124 dz: -84 da: -108 df: 0.0048076 Military grid system: --------------------- origin: E015 scale: 1.0000 false E: 3500000 false N: 0.0 !!! GPS has to be set in metric system when you enter those figures !!!!! Best Regards Zdenek