Ref: 08260007
Title: Explanation of Drivers for Windows 3.0 Memory Management
Date: 11/7/90

Copyright 3Com Corporation, 1991.  All rights reserved.

This is an overview on the Windows 3.0 memory management drivers.  It
includes some details that are not in the Windows User's Guide.


EMM386.SYS:

Emulates expanded memory capability using extended memory.  It should
only be used if the user has an application that requires expanded memory.
This driver can be used only on 80386/80486 machines.

There are several options, but the default values work for most users,
with one exception: in enhanced mode, add the parameter "d=48" to the
"device = emm386.sys" line.

For more information, see the Windows User's Guide and the 5/1/90 README.TXT
that is included with Windows 3.0.


HIMEM.SYS:

Makes available the first 64 KB (at least) of extended memory for some
programs that can load high, such as the MS Enhanced Redirector.  (Note:
HIMEM.SYS cannot be used to load the Basic Redirector high.)  This driver
can be used on 8088/8086 as well as 80286/386/486 machines because it uses
segment wrap-around at FFFE and enables the A20 address line.  HIMEM.SYS
is required in all modes (real, standard, and enhanced) to enable Windows
to access and manage extended memory.

There are several options but the default values work for most users.
Some options are disabled when Windows is running in enhanced mode.

For more information, see the Windows User's Guide, the 5/1/90 README.TXT,
and the 6/30/89 READMEEM.TXT that is included with Windows 3.0.


RAMDRIVE.SYS:

Uses extended, expanded, or conventional memory for a RAM-based logical
disk drive (that is, a named drive such as F:).  Replaces the original
VDISK driver, which cannot use expanded memory.

There are options for disk and sector size and the number of directory
entries.  There are also switches to enable extended or expanded memory
that most users will want to use.

For more information, see the Windows User's Guide and the 6/30/89
READMEEM.TXT that is included with Windows 3.0.


SMARTDRV.SYS:

Uses extended or expanded memory for transparent disk caching for hard
disks (anything on Interrupt 13h).  Network and floppy drives are not cached
by this driver.  It works on 8088-80486 machines, and is limited by CPU
addressability.

Has options for setting cache size and to enable use of expanded memory.

For more information, see the Windows User's Guide, the 5/1/90 README.TXT,
and the 6/30/89 READMEEM.TXT that is included with Windows 3.0.

