INF: Windows Applications Should Not Use EMS Memory

ID Number: Q76689

3.00

WINDOWS

Summary:

One of Windows's advances over MS-DOS is its ability to have code

loaded for more than one application simultaneously. Applications that

are loaded cooperate and share the processor and screen.

Under Windows versions 1.x and 2.x, getting Windows, DOS, and the

applications to fit into memory simultaneously was a feat of software

engineering. Windows made EMS memory [memory made available through

the use of expanded memory specification (EMS)] calls to manage

memory. If a particular application needed to manage a large memory

space, the application was also allowed to make EMS memory calls.

Windows 3.0 exploits the protected modes of the 286 and 386 chips to

provide much more memory for applications to use. Windows manages both

expanded and extended memory for applications that should no longer

need to manage EMS memory for themselves.

Microsoft strongly recommends that Windows applications do not make

EMS memory calls to manage expanded memory. Direct application EMS

memory management will be removed from future versions of Windows.

Non-Windows (DOS) applications that are run in the Windows environment

are not affected by this recommendation.