Thanks, I will check the IDA. My cousin thinks that he has the source, but getting it might take years.
To be blunt without intending to cause offence, it will be faster for him to find the source than for you to learn IDA or Ghidra. Hell, after all these years working with this sort of stuff /I/ find them daunting.
The key is that when a program in a high-level language is compiled it's first changed into an Abstract Syntax Tree (AST). A compiler like Turbo Pascal or FPC takes the AST, optimises it, and spits out an executable... possibly with debugging xrefs to the lines in the original source, but without incorporating either the source or enough information to reconstruct the AST.
Something like Java or .Net, OTOH, in effect distributes the AST as the executable, with the final stages (optimise and convert to opcodes in memory) done at load time.
Even more accessibly, a traditional BASIC would effectively ship a compressed version of the entire source to the end user, making it trivial to list.
So I have /many/ times been asked for a (Pascal etc.) decompiler, by people who thought that since a BASIC program could be listed one written in Pascal was similarly amenable to inspection. But without the AST it's not, and even then you'd lose all comments etc. and possibly some of the variable and function naming.
MarkMLl