Click above to get retro games delivered to your door ever month!

 DOS and Protected Mode
------------------------------------------------------------------------------

     DOS was developed for the 8086/88 microprocessors, so it runs only in
     real mode.  Because the top 384 KB of the first megabyte of memory (the
     High Memory Area) is reserved for the ROM BIOS and memory-mapped
     hardware, there is no more than 640 KB of usable memory that DOS is able
     to address directly.

     CA-Clipper/ExoSpace helps you to overcome this restriction on
     80286/386/486 machines.  CA-Clipper/ExoSpace allows the development of
     protected-mode CA-Clipper programs that run under DOS and can directly
     address much more than 1 MB of memory.