I keep reading in various places that Begin is based on Starfleet Battles. Here are the facts on this.
Begin was not modeled on Star Fleet Battles, it was inspired by the HP 2000 minicomputer Basic game called Trek73, which was written in 1973 before Starfleet Battles existed.
Begin is not a port of Trek73, it just used the ideas of modeling continous movement and events rather than using quadrant-sectors, which was the trend at the time. Begin also uses the story-like text output as it was done in Trek73. The ship systems as they are in Begin 1.65 are also modeled after Trek73.
To learn more about Trek73, check out the Trek73 links section in this group, including a link to the original Trek73 Basic source.
I have also added a few links on Star Trek gaming history.
And incase you missed it, I too have a quadrant-sector Trek game called NCC1701 in Basic which you can download. The source is included with my free HP 2000 compatible Basic interpreter. It is in the Links section of this group as well.