guess.wye

I own a Sony MZ-RH1 minidisc recorder and did a recording of a concert on a 1GB Hi-MD. this was a debut performance for my ensemble. Later on, I put in track divisions while using the battery in the recorder. what i did not notice was the battery was running low. after putting in all the track divisions, the recorder was displaying "SystemFILE WRITING". this process took a while and in the middle of it, the battery died. after reconnecting to the wall socket and subsequently the USB port, all i ever got when i inserted the disc is "format error disc". The machine seems to be unable to read that particular disc. I have tried inserting a blank disc and then trying again but to no avail. Have i lost all the data on the disc? could anyone suggest any ways to recover the data? thank you.