Reverse Engineering Score Perfect to Rescue its Files

Data preservation faces numerous challenges including bit rot and hardware failures, but one of the most difficult is maintaining usability as software becomes obsolete. Maarten Tromp's father had used the Score Perfect music notation program for years, but with development ending in 2012, transferring files to modern software became necessary.

Reverse Engineering Process

Originally released in 1990 for Atari and later ported to Windows, Score Perfect switched to a different file format after version four. Though it could export to MusicXML, this process only captured notes, omitting chords, lyrics and other critical elements. Tromp first attempted to disassemble the program itself, hoping the Visual Basic code might have been compiled to P-code, but discovered it had been compiled to native code.

Interestingly, through version four, the program remained written for Atari and ran in Windows via a simple emulator. After investigating the file-export function with Ghidra, Tromp shifted focus to reverse-engineering the file format itself.

File Structure Discovery

The bulk of Tromp's project involved understanding the file's internal structure. He created empty files in the program, made single changes, and compared the resulting differences to gradually reveal how information was organized. The files contained blocks for different elements like measures and notes, along with tags providing supplemental information.

Through incremental changes, Tromp deciphered the function of most components, ultimately developing a translation program to export Score Perfect files completely to MusicXML. This effort mirrors similar work done to reverse-engineer the Altium file format, though unlike STL files, these projects contained all necessary information within the files themselves.