On a Mac, from the wiki:
Open a blank document in TextEdit, then choose save, and save as vers.req , then select the root folder on your memory card from the menu provided.
Important: in the Save drop-down menu, change plain text encoding from Western (Mac OS Roman) to Unicode (UTF-16), and uncheck "if no extension is provided, use .txt" (if you don't see these options then you need to select "Make Plain Text" from the Format menu). Then click on Save.
Windows just open notepad and save a blank file called vers.req to your card.
then turn the camera on with the card inserted, and hold func/set & press display repeatedly until you see something like 1.00f or 1.00d. That will be your firmware version.
