Lunar Lander

[Andres]

I had an HP-25 and played a lot with the lunar landing simulator. The -25 version didn't adjust for vehicle mass reduction as fuel was consumed. I had little contact with the HP-67, but I recall its version did use the "interactive pause" feature: if you don't enter a burn command, the pause times out and the simulation goes on, assuming a burn of 0. Possibly the -67 version adjusted for mass reduction due to fuel useage, I'm not really sure about this aspect.

The HP-25 lunar langer simulator sparked my interest on flight simulators. I wrote a very crude glider landing simulator for the HP-25 (code is lost), and a passable space shuttle landing simulator for the HP-41C, later improved with synthetic symbols on the display.