> Why not just the full 64k. The sliding window trick was of such limited use compared to the headaches it caused.
As I pointed out in my other comment, the full 64KB would have made it harder to support child processes under DOS.
Suppose I have 300KB of free conventional memory, and run an 8KB program (something like a menu program, for example.) If it starts a child process, that child process has about 292KB of free conventional memory to use. With your idea, it could only have 236KB, because even though the parent process only needs 8KB of memory, it would consume a whole 64KB.
As I pointed out in my other comment, the full 64KB would have made it harder to support child processes under DOS.
Suppose I have 300KB of free conventional memory, and run an 8KB program (something like a menu program, for example.) If it starts a child process, that child process has about 292KB of free conventional memory to use. With your idea, it could only have 236KB, because even though the parent process only needs 8KB of memory, it would consume a whole 64KB.