Halley's Comet orbit plotted by a Timex/Sinclair 2068

This program plots the orbit of Halley's Comet, starting in 1986. Written by Roald Schrack and published in his user group's newsletter, the CATS Newsletter, it's a short but fun demo.
You can read the article here:
archive.org/de...
Tim Swenson typed in the program.