Contents of the MEMSIM32.DOC file
MEMSIM is an Expanded Memory Manager (EMM) which provides the
functions described in the LOTUS/INTEL/MICROSOFT (LIM) Expanded
Memory Specification (EMS), version 3.2.
( Lotus is a trademark of Lotus Development Corporation
Intel is a trademark of Intel Corporation
Microsoft is a trademark of Microsoft Corporation )
MEMSIM creates a file on the hard drive that you designate and
treats this file as Expanded Memory. You can specify a maximum of
approximately 32 megabytes for the file length.
MEMSIM does not attempt to manage any Extended Memory which may be
present on your system; if you invested thousands of dollars in add-on
memory boards for your system, MEMSIM is probably not for you. Also,
programs that already provide disk paging schemes will probably run more
efficiently with their own built-in paging.
MEMSIM is being distributed as SHAREWARE. This means that you are allowed
to try the program and then, if you find it useful and intend to use it,
register your copy by sending $25.00 to:
Harris Computer Consulting
6779 Beadnell Way #103
San Diego, CA 92117
You are also allowed to distribute the program, provided that you do not
modify it and that all accompanying files (including this documentation)
are distributed with it.
You may not charge any fee for use, copying, or distribution of MEMSIM.
Clubs and user groups may distribute MEMSIM, charging a nominal fee
not to exceed eight dollars to cover the cost of media and handling,
provided that it is made clear that the charge is not in lieu of the
$25.00 registration fee paid to Harris Computer Consulting.
Companies requiring billing should send a purchase order to the above
address, along with the name, address, and phone number of a person to
contact regarding payment.
Registering this version of MEMSIM automatically registers you for any
future versions of MEMSIM. Whether future versions will be developed
depends upon the number of registrations received for this version. If
you would like a disk containing the current version of MEMSIM, please
add $1.00 to the $25.00 registration fee and specify whether you need
a 360K or a 1.2M 5" floppy disk.
MEMSIM was designed to give your programs access to memory beyond
DOS's limit of 640KB. Many programs provide support for this extra
memory access by calling on an EMM. MEMSIM is an EMM which uses your
hard disk to simulate the Random Access Memory (RAM) managed by
other EMMs. Examples of software that can use MEMSIM are spreadsheet
and word processor programs.
Disclaimer of Warranty
Harris Computer Consulting hereby excludes all warranties relating to this
software and documentation, whether express or implied, including, without
limitation, any implied warranties of merchantability and/or fitness for a
Harris Computer Consulting shall not be liable for any damages, whether
direct, indirect, special, incidental, or consequential, resulting from
the use of this software and documentation, due to loss of data or any
In no event shall Harris Computer Consulting's liability for any damages
ever exceed the price paid to Harris Computer Consulting for the license
to use this software, regardless of the form of the claim.
The person using this software bears all risk as to its quality and
MEMSIM Operating Instructions
There are two versions of MEMSIM: MEMSIM32.286, which contains 80286 machine
instructions and MEMSIM32.08X which contains machine instructions suitable
for 8086, 8088, and V-20 microprocessors.
These operating instructions apply equally to either file but this
documentation shall refer, from now on, to MEMSIM32.08X, which works with
any of the microprocessors; you select the file that's right for your
MEMSIM is loaded into your computer's memory at boot time with an entry
in your CONFIG.SYS file, and remains resident until you turn off the
You should first copy memsim32.08x to a BOOTABLE FLOPPY disk and modify
its CONFIG.SYS to include the following:
This is the simplest CONFIG.SYS entry you can use, and it requires that you
have at least 262,144 bytes free on drive C: to accomodate the simulator
I recommend that you try it with a floppy disk first, until you get the
configuration you require. Then you can move it to the hard drive, if you
When you boot from this floppy disk in drive A:, a file will automatically
be created on drive C:\ called MEMSIM.SIM large enough for 16 pages of
expanded memory. Each expanded memory page is 16,384 bytes (16KB) in size,
so there needs to be at least 262,144 bytes (16 * 16KB) of free space on
your hard disk when you boot for the first time.
Two switches are allowed in the CONFIG.SYS entry: one to supply the name
and location of the simulator data file and the other to control its size.
The format for the pathname switch is:
which would create and use a file named sim.dat in the root directory on
drive D: 262,144 bytes in size. It is important that you specify the
full pathname for the data file:
/C:\MYDIR\MYSIM.SIM would be an acceptable pathname switch, but
/C:MYDIR\MYSIM.SIM would not.
The format for the size switch is:
which would create a file large enough for 50 16KB Expanded Memory pages
(50 * 16,384 = 819,200 bytes) provided enough space was free on drive C:.
The pathname, in this case, would be the default, c:\memsim.sim. The
minimum recommended number of pages is 16 (default); the maximum possible
number is 2048.
The CONFIG.SYS entry:
device=memsim32.08x /c:\sim.dat /256
would create a 256 page file (256 * 16,384 = 4,194,304 bytes) on c:\ named
sim.dat, again, if enough free space existed on the drive.
The entry in CONFIG.SYS can be placed before or after any other entries
that are present there. If you have extended memory installed in your
system, it will not be treated as expanded memory by MEMSIM. If you are
using MEMSIM, you should use your extended memory as a disk cache, a RAM
disk, and/or with an EXTENDED Memory Manager. Loading any other Expanded
Memory Manager, before or after MEMSIM, should not cause any problems, but
it would would simply be a waste of "conventional" memory: only the last
Expanded Memory Manager loaded would actually be used by your programs.
A sample CONFIG.SYS file is included, named S-CONFIG.SYS. This file assumes
a system with an 80286 microprocessor and 384K of extended memory present
(an AT class machine with 1 Mbyte of total memory) and utilizes all
available extended memory. It also creates a 100 page (1,638,400 byte)
EMM simulator file on C:\. I would suggest that you copy your current
CONFIG.SYS file to another file (for example NORMAL.SYS) and then replace
it with S-CONFIG.SYS (by typing "copy s-config.sys config.sys") when you
want to use the simulated EMS memory provided by MEMSIM, and then restore
your original system configuration (by typing "copy normal.sys config.sys")
when you don't. Of course, you should modify S-CONFIG.SYS to meet your own
Also included is a program called MEMFCHK.EXE which tests all of the files
supplied with MEMSIM for modification or corruption. Type "memfchk ?" for
instructions on usage of MEMFCHK.EXE.