OMG, Good memories, when what you needed many times you had to do yourself. I wrote my first pascal program with TP 1.0, a Karel compiler and a dbase style handler with a quite similar operation with TP 4.0 before 1991, and i have worked with all Delphi versions including 16 bit 1.0.
I can write you a table component that allows conect with a .dat file and its indexes, but I only have one question, do you want it to be BTrieve style, or BTrieve compatible?, because i don't have the file format structure, and it is what I need to be able to make it compatible. ISAM is not a problem.
Best regards.