hello I bought a Casio fx-CG20 and I can not upload data and text on the calculator, the files are ".3 gm" and do not know how to create them, you can help me' thanks.

excuse me for my elementary english

You will need some way to convert things to the g3m format, and this isn't easy.
Casio has made it difficult to write things on the computer and transfer them to the calculator. You're basically supposed to write notes in the calculator, in eActivity for example.
There's a way to send text from the computer to the calculator: save the text as a .txt file, then connect the calculator to the computer and put the text file on the @MainMem/Programs folder.
When you disconnect the USB, the text file will be converted to a program. It will show up on the "Programs" menu on the calculator, where you can edit it and copy the text to a eActivity, for example.

perfect thank you so much!=) =) =) ....and another question....is possible load the jpeg photo?

Yes it is, but make sure the JPEG isn't progressive. See my JPEG image viewer here: http://www.cemetech.net/forum/viewtopic.php?p=197974