Just in case anybody else ever needs to know the format for FCEUX’s debugger’s config files (.deb), here it is, based on the source code for version 2.1.5 (found in \src\drivers\win\pref.cpp) and the contents of actual .deb files.

This is not an open or publicly documented format and may be different for different versions. Some of the data types used in the source code may be platform-dependent.

// FCEUX 2.1.5 .DEB FILE FORMAT


// int is 32 bits, short is 16 bits, byte is 8 bits.
// uint = unsigned int
// ushort = unsigned short
// uint16 = 16-bit unsigned integer
// byte = 8-bit integer

// Redundant types are a result of information from different sources. 
// I don't know if anything is platform-dependent.

// Debugger Window
byte*           SymbolicDebugEnabled
uint            BookmarkCount
ushort[]        Bookmarks

BreakPoint[65] {
    uint16*         AddressStart
    uint16*         AddressEnd
    byte*           Flags

    uint            ConditionLen
    char[]          Condition
    uint            DescripLen
    char[]          Descrip
}

// Hex Editor Window
int*            HexBookmarkCount
HexBookmark[] {
    uint*           Address
    uint            DescripLen
    char[]          Descrip
}