Now I've run into another problem...

I was using a unit found on the net for playing multiple simultaneous sounds in my game (http://www.programmersheaven.com/dow.../download.aspx) and it worked like a charm in real mode. However, to get it to work in protected mode, the IDE needs to leave enough extended memory for the sounds it has to load. From the unit's .doc file:

Code:
This library will work in the real-mode IDE but requires a little work
to get it to work in the protected mode IDE.  By default, the IDE's DPMI
extender uses all extended memory.  The demo requires 200k of extended
memory, and any programs using SMIX require extended memory to hold all
the sounds.  You can decrease the amount of extended memory used by the
IDE by setting the DPMIMEM environment variable:
  SET DPMIMEM=MAXMEM x
where x is the number of kilobytes of extended memory to use for the
IDE.  You will have to find a balance between memory left over for your
program and memory available for IDE use.  (Source code, online help,
compilation...)
I can't figure out where to set the DPMIMEM environment variable...?