To transfer save game files between a PSTV and PC use the Content Manager Assistent.
To convert a PlayStation 1 save game contained in a memory card file you can first use MemcardRex to extract the save game to its own file (resulting in a MCS file) and then convert this file to a PSTV save game file (resulting in a VMP file) using web save editor.
Listed here are the save game backup files for their respective game.