Contents of the CTMAP096.DOC file
CTMAP 0.96 - DOS memory extender for 80286, 80386 and '386SX "AT" computers
which use Chips & Technologies DRAM controller chips.
LOADHIGH 0.98 - Makes memory-resident software load in high RAM
Copyright 1989-1990, Burton Systems Software. All rights reserved.
Burton Systems Software
P.O. Box 4156, Cary, NC 27519 USA
The CTMAP package contains two programs: CTMAP and LOADHIGH.
If you are using an 80286, 80386 or 80386SX computer which has a Chips
and Technologies 82C302, 82C307 or 82C212 DRAM controller chip, CTMAP can
dramatically increase the amount of usable RAM memory available to DOS
- from the usual 640K to as much as 944K, depending upon what adapters
you have installed in your computer.
If you do not use EGA or VGA graphics, them 64-96K of this additional
memory will usually be contiguous with the 640K of memory which DOS
normally uses, increasing that area to 704K or 736K. Additionally, CTMAP
can enable DOS to use up to 240K of discontiguous RAM, located above the
display adapter RAM and below the ROM BIOS. However, some programs can't
use discontiguous RAM (and CHKDSK ignores it).
LOADHIGH is used to make programs (expecially TSRs) load in high memory.
By installing your TSRs in high memory (above the display RAM), you
can further increase the amount of contiguous low memory available for
other application programs.
For operating instructions, run CTMAP like this:
Typical usage with EGA or VGA aapter is:
CTMAP /A -A -B
CTMAP /A -A -B -C
Typical usage with monochrome adapter is:
For operating instructions, run LOADHIGH like this:
HOW IT WORKS
CTMAP is simplicity itself. Mainly, what it does is manipulate the
hardware registers in the C&T DRAM controller chip to enable the "extra"
RAM which is already there on your computer, then it patches up the DOS
memory control block chain so that DOS "knows about it."
The DOS memory control block chain is documented in a number of places.
See, for instance, the Microsoft's MS-DOS Encyclopedia, or the Turbo
Pascal source code for Kim Kokkonen's famous MAPMEM utility.
LOADHIGH is even simpler than CTMAP. Mainly what it does is patch the
"owner" field in DOS memory control blocks so that DOS considers them
used or available.
CAVEATS, PROBLEMS, ETC.
1) No warranties of any kind are expressed or implied. Use at your own
2) If you find that some I/O device or EMS memory card fails when you
use "CTMAP /A", you can use explicit "-xx" options to prevent CTMAP from
using particular areas of RAM. We suggest trial and error to determine
which memory segments you can and cannot allow CTMAP to use. For display
adapters, the most likely culprits are the A, B and C segments. Example:
CTMAP -A -B -C /A
3) A few TSRs may not work when loaded in high memory. In particular,
TSRs which increase the size of the keyboard type-ahead buffer cannot
work when loaded in high memory.
4) We've noticed that some command line editor programs get confused
about which retrieval buffer to use if they are loaded in high memory or
if they are loaded before CTMAP and LOADHIGH are run. DOSEDIT, NDOSEDIT
and RETRIEVE have this problem, so if you use one of them, you should
install it at the end of your AUTOEXEC.BAT, after the "LOADHIGH OFF".
However, CED and PCED (two other popular command line editors) do not
seem to have this problem. We've not yet tried ANARKEY (yet another
command line editor).
5) So far, we have been unable to make device drivers load in high memory.
If you are an expert on the guts of DOS and know how to do this, we'd
welcome the help. In the meantime, we suggest that users of CTMAP use
a TSR-style RAMDISK or CACHE program instead of DOS's VDISK, or else (if
you have more than 1 megabyte of RAM memory), run it with the buffer in
extended or expanded memory.
6) We're using undocumented DOS features to manipulate the DOS memory
pool, so we cannot guarantee compatibliity with future DOS releases.
If you have a problem, let us know - perhaps we can solve it.
7) We recommend the use of Chris Dunford's PMAP program to display the
DOS memory pool. It is very similar to Kim Kokkonen's MAPMEM, but it
does a better job of displaying information about "high" memory. If
you received CTMAP on diskette, you may have also received a copy of
PMAP. However, PMAP is not a part of the CTMAP package! PMAP is a
different product, from a different company; see PMAP.DOC for license
information and legal restrictions on the use and distribution of PMAP.
8) Note that some programs, such as MAPMEM and DOS CHKDSK will not
display information about DOS RAM above the video display. Also,
Norton-SI will tell you about high RAM... but will not tell you whether
it is part of the DOS memory pool. This does not mean that CTMAP did
not work! You can run "LOADHIGH OFF" for a quick display of available
RAM (do it before and after running CTMAP to see the difference!).
Better yet, use Chris Dunford's PMAP (for details, use "PMAP /R").
Most local area network adapters use some high address space. CTMAP
will generally detect the LAN adapter RAM and/or ROM, and not enable
general purpose RAM at that address. In other words, CTMAP will
probably not interfere with your LAN, but the presence of the LAN
adapter will probably reduce the amount of RAM which CTMAP can add to
DOS's memory pool.
If you can choose the memory address for your LAN card, it is a good
idea to try to pick an address adjacent to either the ROM BIOS (at
F0000) or the display RAM (the address depends upon your display
adapter). This will allow CTMAP to add the high memory to DOS's
memory pool as one big chunk of memory instead of two little chunks,
so that bigger programs will fit in it, with less wasted RAM.
We use Novell Netware on an Arcnet, using Network Innovations' PcARC
network adapter. It uses 16K of RAM at an address which is selected
by DIP switches on the board. The most common setting, and the one
expected by Novell's ANET3.COM program is:
D0000 (the default)
However, we relocated it to:
EC000 (just below the BIOS RAM)
(Note: the Network Innovations documentation refers to these addresses
as D000H and EC00H.)
To use the reconfigured card with one version of Novell Netware, it was
necessary to patch ANET3.COM. That version of Netware uses a 50605 byte
version of ANET3.COM, dated 05/16/88. When run with the "I" option it
Advanced/SFT NetWare V2.01-2 Workstation Shell for PC DOS V3.x
Copyright (c) by Novell, Inc. 1983, 1987
LAN Option: Standard Microsystems ARCNET
That version of ANET3.COM is fairly easy to patch (if you are
comfortable using DOS debug). Simply use DOS debug to search the
file for the eight instances of 00 D0, and change all eight instances
to 00 EC.
Recently, we upgraded to a newer version of Netware which had to
be patched differently. Instead of ANET3.COM, it has programs named
IPX.COM and NET3.COM (or NET4.COM).
IPX.COM is the program which needs to be patched. Ours is 27966 bytes
long, dated 8/25/89. When installed for our LAN card, it displayed:
Novell IPX/SPX V2.15
(C) Copyright 1985, 1988 Novell Inc. All Rights Reserved.
LAN Option: Standard Microsystems ARCNET/Pure Data V1.00
Hardware Configuration: IRQ = 2, I/O Base = 2E0h, RAM Buffer at D000:0
In our case, it was easy to patch the IPX.COM memory address. We simply
used DOS debug to search the file for the first instance of 00 D0, and
we changed it to the desired address (00 EC, in our case). For esthetics,
we also patched the string which follows to indicate the proper address
("EC00:0" instead of "D000:0"), so that the patched version of IPX.COM
displays the proper address when it is installed:
Hardware Configuration: IRQ = 2, I/O Base = 2E0h, RAM Buffer at EC00:0
IPX.COM contains a table of 18 combinations of hardware settings; the spot
we patched was the first entry in the table. If your LAN uses a different
interrupt level (IRQ) or I/O Base, you'll have to patch a different table
This software is not free. You may try it out on your computer(s) at no
cost, but if you like it and decide to continue using it, or if you add
it to your AUTOEXEC.BAT, then you must register it at a cost of $30 per
Register by sending $30 per computer to:
CTMAP 0.96 registration
Burton Systems Software
P.O.Box 4156, Cary, NC 27519 USA
Please include the following:
Your full name, your company (if any), your telephone number(s), your
mailing address (including country), the number of computers you are
registering for use of CTMAP 0.96, the brands and models of your
computers & your version of DOS, and your payment of $30 US (or $40
Canadian) per computer. Also, please answer the questions: "Are you
a programmer? In what computer languages?"
Payment should be by check or money order on a US or Canadian bank, or
by Visa, MasterCard or EuroCard charge. If paying by credit card, please
be sure to include your credit card number, expiration date, type of card
(Visa or MC), and the name on the card; and please sign your letter. Or,
with a credit card, you can register by telephone or FAX. Call us at
(919) 856-0475 (if you are using a FAX, we will transfer your call to the
FAX machine upon request; after hours, you can use a touch-tone telephone
to make our Voice Mail system transfer your call).
You are encouraged to give copies of this software to your friends and
colleagues for trial on their computers. You are free to "upload" this
software to any computer bulletin board system (BBS). You may charge
recipients of this software a fee of no more than $6 US plus the cost
of the distribution media, provided that purchasers are forewarned that
continued use requires registration with Burton, and that registration
costs $30. However, under no circumstances may "patched" or otherwise
modified copies of this software be distributed without prior written
permission from Burton.
Manufacturers and distributors of computer equipment should contact
Burton to purchase distribution licenses for customized versions of this
DISCLAIMER OF WARRANTY
No warranty is expressed or implied. Use this software at your own risk.
However, if you encounter problems, or if you have suggestions for
improvement, we would like to hear from you.
WHO ARE WE?
Burton Systems Software is a commercial software development company
located in Raleigh, North Carolina. We specialize in systems software
and software development tools for programmers. We are best known for our
TLIB (tm) Version Control System for MS-DOS (and soon for OS/2). TLIB is
the fastest, most powerful, and easiest to use version control software
available for PCs. It elegantly solves many of the headaches attendant
to software development. But don't take our word for it - give us a call,
and we'll gladly send you more information, including a long list of
quotes from enthusiastic magazine reviewers. Or try it out - TLIB comes
with a full 90 day warranty (unlike CTMAP!). Our telephone number is
When you register CTMAP, you'll receive a coupon worth $30 off the price
of a TLIB Version Control System. You may also receive an updated
version of CTMAP (at our option), if we have improved it significantly
Note to TLIB customers: if you got CTMAP with TLIB, you can register for
free - sort of a pre-redeemed coupon. Just mention your TLIB serial
number in a letter which says "I'm using CTMAP; please register me."