               RELEASE NOTES FOR MATHCAD 4.0
               ------------------------------

These notes provide last minute information on this version
of Mathcad as well as corrections to the documentation.

                    CONTENTS:
     1:  Preparing to Install
     2:  Bind Time Error Messages
     3:  API 'Reg Key Value' Failure Error Messages
     4:  WIN32S and virtual memory
     5:  Incompatibilities
     6:  Installation on Badly Fragmented Disks
     7:  Compressed Drives and the Windows Swap File
     8:  Difficulty Locating MCAD.DLL or EFIUTIL.DLL
     9:  Low Memory Conditions
    10:  What are WIN32S Libraries
    11:  Additions to Documentation
    12:  Changes to Documentation

1: PREPARING TO INSTALL
Before installing:

1.   Make sure that you have at least 13.5 MB free on your
     hard drive. Although Mathcad 4.0 needs only 10 MB once
     installed, the installer creates temporary files
     requiring additional space.

2.   Make sure you have disabled any virus checking software

3.   Make sure your system is set up to run Windows 3.1 in
     386 enhanced mode. The installation script will not run
     otherwise.

2: BIND TIME ERROR MESSAGES
Neither the installation program nor Mathcad will run on
an 80286 based machine or on any machine running Windows
3.0 or OS2. If you attempt to install on such a machine
you will get one of a variety of bindtime error messages.
For example, on a 80286 machine you will see "Bindtime
error: Cannot load library: 'KRNL386.EXE.'"

3: API 'CREATE REG KEY VALUE' FAILURE
If you see an error message like "API 'Create Reg Key Value'
Failure" during installation it means that your
\WINDOWS\REG.REG file is either read-only or corrupted. You
can often fix this problem as follows:

1.   Check to make sure REG.REG is not read-only. To do so,
     open File Manager, select REG.REG and choose Properties
     from the File menu. If the Read Only box is checked,
     uncheck it and try installing Mathcad again.
2.   If step 1 didn't work, you'll have to run REGEDIT, a
     Windows supplied utility. Choose Run from the Program
     Manager's File menu and type REGEDIT /V in the Command
     Line text box.

3.   Once REGEDIT is running, click on the "\" at the upper
     left corner of the window.

4.   Choose Save Registration File from REGEDIT's File menu
     and specify a temporary name like OLDREG.REG.

5.   Exit to DOS, rename the original REG.REG file, and
     restart Windows.

6.   Run REGEDIT /V again, as described in step 2.

7.   Choose Merge Registration File from REGEDIT's File
     menu.

8.   REGEDIT will prompt you for a file name. Use the same
     one as in step 4.

9.   Click OK, exit Windows, reboot the computer and try
     installing Mathcad again.

4: WIN32S AND VIRTUAL MEMORY
If you see a dialog box saying

"WIN32S requires running virtual memory enabled.
            Reinstall WIN32S"

1.   Open up the Windows Control Panel and double-click on
     the 386 Enhanced icon to bring up a dialog box.

2.   Click on the Virtual Memory button.

3.   Click on the Change button and create a permanent swap
     file.

4.   Close all dialog boxes by clicking OK and restart
     Windows.

WIN32S libraries require that a portion of your hard disk be
set aside for a "swap file." It uses this file to create
"virtual memory."

Since virtual memory makes use of the hard disk, it is
slower than actual RAM. You can improve its performance by
creating a permanent swap file. Such a file makes use of
contiguous blocks on your hard disk.

The size of a permanent swap file is constrained by the
smallest of the following three limits.
1.   The amount of contiguous hard-disk space. You can
     increase this by defragmenting your hard disk using any
     of a number of commercially available utilities.

2.   50% of your free disk space.

3.   Four times the amount of RAM on your system plus 4MB.
     Thus, 3MB RAM allows no more than 3MB*4 + 4MB or 16MB
     of swap file space.

5: INCOMPATIBILITIES
Shareware
Certain shareware memory monitoring software may be
incompatible with Mathcad. If you are running such software
and experience unexplained crashes, try disabling any memory
monitoring software you have running.

Anti-virus software
Most anti-virus software will interfere with the
installation program. Be sure to disable any such software
before installing Mathcad. You can re-enable anti-virus
software after Mathcad is installed.

Math coprocessors
If you get obviously inappropriate error messages when
running Mathcad, for example an "illegal range" pointing to
a simple range variable assignment, you may have an
incompatible coprocessor.

Some older 80387 coprocessors made by IIT have this
property. If you have this coprocessor, call IIT customer
support at 800-832-0770 for a replacement.

Some older computers are equipped with an 80287 coprocessor
and an 80386 CPU. Although fundamentally incompatible, this
combination works for many software packages. However,
because of its extensive use of the coprocessor, Mathcad
tends to expose even minor incompatibilities in this
configuration.

Printers
If you can't choose Print from the File menu and you have an
HP-Deskjet 500C printer you may need to upgrade your printer
driver to version 3.0 or later. To do so, call HP at 208-
323-2551.

Print Spoolers
The print spooler WINJET comes with a file WINSPOOL.DRV.
This is incompatible with the WIN32S file having the same
name. When you attempt to install Mathcad with WINJET
installed, the installation program quits about halfway
through the process.

To circumvent this problem, do the following:
1.   Comment out the following lines in your SYSTEM.INI file
     by preceding each line with a semicolon.
          DEVICE: = LMHERALD.386
          DEVICE: = LMMI.386
          DEVICE: = LMCAP.386

2.   Reboot the computer.

3.   Install Mathcad 4.0.

4.   Uncomment the above lines by removing the semicolons
     you placed in the SYSTEM.INI. file.

5.   Reboot the computer.

6: INSTALLATION ON BADLY FRAGMENTED DISKS
Since your computer frequently saves and deletes files to
your hard disk, it is normal for the hard disk to become
"fragmented." This means that there isn't much contiguous
free space on your disk. The result is that many files,
especially big ones, have to be saved in small pieces in
different parts of the disk.

If your hard disk is badly fragmented, the computer has to
hunt all over your hard disk for free space. This will
significantly slow the installation. You may wish to
unfragment your hard disk using any of a number of disk
optimizing utilities. Doing so will increase performance not
only for Mathcad but for all applications on your system.

7: COMPRESSED DRIVES AND THE WINDOWS SWAP FILE
If you're using a disk compressor such as Stacker, you must
place the Windows swap file on your host drive. You cannot
place a swap file on your compressed drive.

If you're using DBLSPACE, DOS 6.0's compression utility,
Windows will be able to create a permanent swap file only on
your host drive. If you don't have the space to create a
permanent swap file there, you can still run Mathcad by
creating a temporary swap file on your compressed drive.

8: DIFFICULTY LOCATING MCAD.DLL OR EFIUTIL.DLL
If you are upgrading from Mathcad 3.1 you may encounter the
error message "Cannot find MCAD.DLL" or "Cannot find
EFIUTIL.DLL" These messages are benign. They merely indicate
that you have an older 16-bit DLL on your system. If you
have purchased Mathcad Function Packs in the past, you will
find that these functions are undefined. None of the
functions described in the User's Guide are affected.

To update to a 32-bit file, please call MathSoft Technical
Support at 1-800-628-4228 between 9:00 and 5:30 Eastern
time. From outside the U.S.A. or inside Massachusetts, call
617-577-1017.

9: LOW MEMORY CONDITIONS
The memory requirements given in the User's Guide are
adequate for normal use. It is possible under some
conditions to run out of memory.

Such conditions might arise:

1.   When many other applications are running at once.

2.   When you're making unusually heavy use of symbolic math
     or SmartMath features, or

3.   When you work with very large arrays. Since each
     element of an array requires 8 bytes of memory, a
     single 1000 x 1000 array will, by itself, use 8 MB of
     memory.

Under these conditions, it is prudent to save your document
frequently.

10: WHAT ARE WIN32S LIBRARIES
The Mathcad installation script automatically installs
Microsoft's WIN32S libraries. These Microsoft libraries
permit Mathcad 4.0 to use a limited subset of Windows-NT
features. The 32-bit datapath made available through the
WIN32S libraries makes Mathcad run significantly faster.

Once installation is complete, you'll find the WIN32S
libraries in your \WINDOWS\SYSTEM\WIN32S directory.

11: ADDITIONS TO DOCUMENTATION

A: Printing
You may find options for collate and number of copies grayed
out on your Print dialog box. Since Windows uses the same
Print dialog box for all printers, these are probably gray
because your particular Windows printer driver does not
support these features.

B: Colors
Mathcad can display only those colors available on your
display. If your colors do not display as you expect them
to, check your available colors through the Windows control
panel.

C: Zooming Windows
You can edit both math and text when zooming in for a close-
up view of your document (zoom factor > 100%). However, when
you zoom out for an overall view (zoom factor < 100%), you
can edit only math regions. You cannot edit text. All other
functions are as described on page 58 of the User's Guide.

D: Fonts
On some systems, fonts on the screen are a slightly
different width from the corresponding font on the printer.
Because of this, some text and math regions may extend
beyond the right margin when printed even though they do not
appear to do so on the screen.

E: Copy Answer
As mentioned on page 115, when you copy a numerical result,
you copy only up to the precision displayed. However, if the
result is displayed with trailing zeros, these zeros are not
copied with the result.

When you copy a numerical result to the clipboard using Copy
Answer as described on page 115, you cannot use that number
in conjunction with the "Substitute for Variable" command on
the Symbolic menu. To do so, first paste it into a blank
space and copy it again.

F: Polar plots -- Resizing
Since polar plots must be circular, Mathcad does not permit
you to resize a polar plot arbitrarily as you would an X-Y
plot. When resizing a polar plot, always place the mouse
pointer on the lower-right corner of the plot.

G: Parametric Surface Plots
You cannot show the axes on parametric surface plots such as
that shown on page 362.

12: CHANGES TO DOCUMENTATION
The operator palette has changed since the User's Guide was
printed. A button for the symbolic equal sign "->" was
inserted below the button for the numerical equal sign "=".
This change affects most screen-shots in the User's Guide.
