Vanara

I tried to play a sony HIMD disc I recorded years ago just now on my Sony MZRH910 and it worked ok for a few minutes, but when i tried again it said FORMAT ERROR. I dont want to reformat it, as it has an irreplaceable recording on it. It said the same FORMAT ERROR when I tried it in another machine, a Sony MZM200. Other discs seem to play ok. The disc was recorded on one of these machines. Is there a way to retrieve the data? I am using a mac so I cant use the sonicstage software. thanks