Not the original cover. No packaging for either TRS-80 title has surfaced; this is a modern illustration made for this archive, after the locations in Betts’s design notebook.
Forbidden Valley
A jungle adventure. The notebook grid opens at a wreckage with a fossil, torch and matches, then works through rocky outcrops, a carnivorous plant, caves of stalagmites and fluorescent pools, a monstrous spider and its web, a native village where the player is tied to a stake, a bubbling mud pool with a hungry dinosaur, and a crumbling stone bridge over boiling lava. The last message in the verb table is line 11000, “Escape — end of adventure”.
Source: Brian Betts's design notebook — the game itself is not known to survive.1981 · No year on any surviving artefact — placed with The Secret of Flagstone Manor, whose title screen reads 1981
No copy of the program is known to survive anywhere. The design notebook and a sheet of unused cassette labels are all that is left.
Design notebook
A page from Brian Betts’s working notebook: the verb table with the BASIC line number each command jumps to, an abbreviation key for the puzzles, and a hand-drawn grid of every location. A sheet of unused printed cassette labels lies across the spread.
