So it will not run on my Sinclair Spectrum then.

Sadly not.

Not much of a market for that one these days (despite it being the most popular machine "back in those days").

Tape-based databases were a "whole new ball game", of course. Not for the feint-hearted, and not really viable in today's terms. But that was all we had at one time. All part of the evolution (that is generally taken for granted by most folk now)!

VFP