(1) (
Unlicensed
Mobile
Access) See
GAN.
(2) (
Upper
Memory
Area) Memory in a PC between 640K and 1M. This region is broken into upper memory blocks (UMBs) reserved for video memory and other peripherals. In the days of DOS and limited memory, people wanted to run larger applications that took up much of the lower 640K. A variety of different memory managers became available to load and manage drivers and TSRs into unoccupied UMA blocks. EMM386, which came with DOS 5 and Windows 3.0, was an example of such software. See
MMIO,
EMM386.EXE and
QEMM.
Memory Allocation in a PC