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

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

I: 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.

II: 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.

III: WINDOWS SWAP FILES

Windows 3.1 sets aside a portion of your hard disk 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 if you have not already done
so. 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 as
    described in section I above.

(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.

IV: 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 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
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.

V: 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.

Page 9
The file "mathcad.clp" in the CLIPS directory is actually
named "mathcad.smr."

Page 89
The Tab key in a text region moves to the end of the current
word rather than to the beginning of the next word.

Page 139
In Figure 1, the default system of units is CGS. To
reproduce this example, choose Units from the Math menu and
make the default system of units CGS.

Page 245
Solve blocks can solve fifty equations in fifty unknowns,
not forty-nine.

Page 362
The subscript for theta in the definition of Z in Figure 6
should be n rather than m.

VI: Difficulty locating MCAD.DLL

If you are upgrading from Mathcad 3.1 you may encounter the
error message "Cannot find MCAD.DLL." This message is a
benign one. It merely indicates 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 1-800-628-4223
between 9:00 and 5:30 Eastern time. From outside the U.S.A.
or inside Massachusetts, call 617-577-1017.


VII: INCOMPATIBILITIES WITH 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.

VIII: INSTALLATION ON 286

Neither the installation program nor Mathcad will run on an
80286 based machine. If you attempt to install on such a
machine you will get the error message "Bindtime error:
Cannot load library: 'KRNL386.EXE.'"
