Originally posted by PhilippeG You can use
The Unarchiver, available from the App Store. A pretty good replacement to the default app.
Hi Philippe! Thank you for your reply.
Actually what I should be asking in the first place is : whether the .frm file (the new firmware file) which I have downloaded need to be converted to a .zip file first before I could copy it to the root of my formatted SD card.... or I could just copy it as it is (as frm file). Any idea? (By the way, I tried to open this frm file with The Unarchiver but it didn't work). I have been trying to update my Ricoh GR's firmware but to no avail.