Nothing I do to DOSBox seems to affect the available memory (found by using the Z:\MEM command). It always reads: 637 kb free conventional memory, 15296 kb free extended memory, 15296 kb free expanded memory.

Changing the CPU cycles via F-12 does not change the amount of CPU being used, which is at a constant 70% or so on the Task Manager. It likewise does not change the amount of available memory found with the MEM command. Changing the frameskip also does not change anything here.

I have a Pentium III with 498 MHz and 512 MB RAM. My OS is Windows XP. I have about 5 gigabytes of hard drive space free on my C drive and about 50 free on my D drive. The programs I'm trying to run through DOSBox are DOS games (specifically, Duke Nukem 3D, Duke Nukem 3D Build level editor, and Supaplex) and work, but are extremely slow and choppy, probably due to the 637 kb conventional memory.

While I am able to change the frame rate and CPU cycles in-game, and this does seem to do something, I can never get the games to work smoothly, which is puzzling given that I've played these games on older, considerably crappier, but DOS-supporting computers with no problems.

My sound card is a SoundBlaster, or some variant thereof, and works fine.

My resolution is 1024 X 768.

So, my question is, why can't I change the available memory (as the README file apparently said I should be able to) and what can I do to make it modifiable?