Dinosaur Sighting: Microsoft Flight Simulator for the IBM PC Jr.

That's the game I always remember wanting to play on the "display PC" whenever I went to the electronics store as a kid.

Makes me pine for my old combat flight simulator game, Birds of Prey (Eletronic Arts). Was on a single 3.5" floppy, & you flew as either a US/NATO or a Soviet/Warsaw Pact pilot with just about any 1980s Cold War plane available (including being able to fly a B-52 or a B-1). And just like this game, a lot of the manual was about how to fly a plane, since it was super-realistic (i.e. you had to turn the engines on before you could set your throttle speed, you had to check your flaps & landing gear, etc.). IIRC, it also had a bit of a "speed" problem with my later PCs.

Alas, being a DOS/Win3.1 game, I had trouble getting it to run on my old XP machine, let alone my new Win7 machine....

...from the original SubLogic for the Apple ][ on up. The originals had no shading or terrain databases; just rectangular outlines for airports and a grid outlining the "world". On the early versions, the screen updated roughly once a second.

...Flight Simulator was the grand test of compatibility. At the time, it was the single program that would test nearly all aspects of a computer's capability and compatibility with the standard IBM machine; especially for graphics. Back when we were first selling clones, booting up a disk of Flight Simulator was what ultimately made the sale.

One interesting problem was that when clones with clock speeds above the standard 4.77 MHz started to appear, early versions of Flight Simulator actually ran too fast, as events were timed via the processor and not the system clock.