IBM PC memory manager software providing HMA. XMMs usually provide this functionality. Named after the 21st address line (A20), controlling the access to HMA.
Last updated: 1996-01-10
^ ♦ A# ♦ A-0 ♦ a1 ♦ A1 security ♦ A20 handler ♦ A-3 ♦ A3D ♦ A4C ♦ a56 ♦ AAC
Try this search on Wikipedia, Wiktionary, Google, OneLook.