n4gix, you wrote:

 

This is the very definition of a "terminate and stay resident" program.

Sorry to pick you up on it, but you are confusing things with programs that could run next to another on single tasking operating systems before Windows. But in Windows, multitasking is done by virtual machines. The screen grabber takes no memory from FSX/P3D, and as far as it's concerned it's the only program running, it runs in it's own process space and can access the full memory - which is virtualised. In the old days, TSR's injected their code into the working space of the current DOS program, a bit like .dll's do now.

Okay Steve, I'll accept your explanation. I guess I'm just showing my age here, since I cut my teeth back in the early sixties developing programs in assembler, and therefore am a true "fossil" now... :blush: