Expanded Memory Specification

Technique used during DOS times in order to access more than 640 KB of RAM memory. Since DOS ran at CPU’s real mode, it only saw 640 KB of RAM memory, thus requiring this technique to access over 640 KB of memory. This technique is no longer used. The file in charge of Expanded Memory technique was Emm386.exe. Microsoft competitors released several expanded memory manager programs more efficient than Emm386.exe. One of the most famous ones was QEMM.