Help, please-Can we "unmaster"?

[shwal1@comcast.]

Uh, oh. We have a Portastudio DPFX01. We are so new to this that we recorded numerous songs one after another, on the same track, without creating a new song for each one. Then, when mastering one of these and exporting it to the laptop, we seem to have lost the rest of the songs. When we go back to the Portastudio to play the other songs, the only one we can access is the section we mastered and exported. Are the other permanently gone or are we missing something?
I 've read and re-read the manual, but can't find what we need. Thanks to anyone who can help.

 

[CoolCat]

do you have a premaster list?

on the 2488, the master is the most recent one used or highlighted, but the premaster has all the songs.

old saying....."when in doubt, read the manual"