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Quick-Start Manual

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Computer Aided Resonator Design (CARD)

Quick-Start Manual

Version 1.4, revised 6/20/02


Copyright 1999 .. 2002
Donald R. Culp
All rights reserved



If this document is reproduced for further
distribution, this title page must be included.


Table of Contents

bulletAbout Krell Engineering
bulletAbout this document
bulletCARD overview
bulletCARD demo
bulletLicense agreement
bulletDistribution files
bulletStarting CARD
bulletLoading sequence
bulletMain program
bulletHow to quit
bulletGeneral help
bulletKeyboard help
bulletMenu help
bulletResults help
bulletSpreadsheet help
bulletBar menu keys
bulletMenu keys
bulletMenu quick-access (hot) keys
bulletHelp window keys
bulletExample resonator
bulletAuto-tune length example
bulletOther examples
bulletProblem resolution
bulletEquipment requirements



About Krell Engineering

Krell Engineering consults in the design of ultrasonic resonators (horns/sonotrodes/probes, boosters, transducers/converters) for frequencies between 10 kHz and 100 kHz. These resonators are designed using finite element analysis (FEA) simulation software. These resonators are used for industrial and medical applications.

bulletIndustrial applications -- welding of plastics and nonferrous metals, cleaning, abrasive machining of hard materials, cutting, enhancement of chemical reactions (sonochemistry), liquid processing, atomization, etc.
bulletMedical applications -- surgical devices for cutting, cauterizing, scraping, and cavitating, dental descalers, etc.

Krell Engineering also provides Computer Aided Resonator Design (CARD) software which facilitates the design of ultrasonic resonators.

About this document

This document is an abbreviated users manual for the demonstration version of CARD (Computer Aided Resonator Design).

To assure that you have the latest demo version of CARD (which also includes the latest version of this document) and to obtain additional information about CARD, visit Krell Engineering's web site at http://www.krell-engineering.com. For other ways to contact Krell Engineering, see the Support section below.

CARD overview

"Computer Aided Resonator Design" (CARD) applies quantitative techniques to the design of acoustic resonators (horns/sonotrodes/probes, boosters). Its goal is to provide assistance in the design of resonators of low-to-moderate complexity. It should be especially useful for designing low-stress resonators.

CARD will aid in designing new resonators or analyzing existing resonators. Resonator dimensions can be selected for automatic tuning, or the resonator can be manually tuned. Resonators up to three half-waves long can be analyzed (99 half-waves will be available in an upcoming version). CARD calculates numerous acoustic parameters, including tuned length, tuned frequency, gain, node location, maximum stress, stored energy, loss, overall quality factor (Q), and weight. When calculating the stress, CARD considers the effect of stress concentrations at radii and slot ends. CARD graphically displays the calculated amplitude, stress, and loss distributions at each point along the length of the resonator.

CARD has been designed for maximum ease of use, so that even those with minimum computer experience should have little difficulty. However, the user must have some understanding of resonator design in order to evaluate the computer-generated output.

CARD demo

The CARD demo is the same as the standard version of CARD (currently version 9.00) except:

  1. The following functions have been disabled:
    a. Saving the resonator design file or modified CARD defaults
    b. Printing the resonator dimensions, materials, or results
  2. A diskette drive is not required for installing CARD.
  3. A copy protection diskette or key is not required.
  4. Only an abbreviated CARD manual is available, which is included in the download.


CARD is designed to assist with resonator design. It is not meant to replace the good judgment of the resonator designer. Therefore, the user assumes full responsibility for the proper use of CARD and any consequences that may result. (See the license agreement.)


License agreement

If you use this demonstration version of CARD (Computer Aided Resonator Design), you must abide by the following conditions.

  1. CARD (comprising both software and manual) is copyrighted by United States Copyright Law to Donald R. Culp, to whom all rights are reserved.
  2. You are free to distribute this demonstration version of CARD to others, provided that you include all of the original files in the original form and that none of these files has been modified in any way. You may not distribute the standard version in any form.
  3. This license may be revoked if you fail to comply with any provisions of this license agreement.
  4. CARD provides only approximate solutions to resonator design problems. (See CARD's online help at \Master topic index\CARD overview\Impedance matching.) Therefore, you assume all responsibility for using CARD within its limitations and for proper interpretation of the results produced by CARD.

    Except for replacement of defective diskettes, the author and distributors of CARD specifically disclaim all other warranties, expressed or otherwise implied, including but not limited to implied warranties of merchantability and fitness for a particular purpose, use, or application. In no event shall the author, distributors, their employees or heirs be liable for any loss of profit or any other commercial damage, including but not limited to special, incidental, consequential, or other damages.

    No oral or written information or advice given by the author, distributor, or their employees shall create additional warranty or in any way increase the scope of this warranty.


Distribution files

The download file is named CARDzip.exe. This is a self-extracting file that contains the remainder of the CARD files. To extract the files, simply run (execute) this file. Note: some of the following files may not be evident until CARD has been completely installed.

  1. CARDinfo.bat: type "CARDinfo" to view the quick-start manual. CARDinfo will display either:
    a. QSmanual.hlp: a Windows help file.
    b. QSmanual.txt: a short text file for DOS users.
  2. Setup.bat: the file for installing CARD.
  3. CARDxxx.exe: the main CARD program (the executable file), where xxx refers to the version number. For example, CARD900.exe is version 9.00 of CARD.
  4. CARD.bat: the file for running CARD.
  5. CARD*.cfg: configuration files.
  6. CARD1.hlp: CARD's online help file. This file is also viewable by typing "Showhelp" at a DOS prompt in the directory where CARD1.hlp exists. This file is displayed during setup. Note: CARD1.hlp is not a standard Windows help file.
  7. Examples.exe: a self-extracting file that contains the resonator example files. This will automatically be installed by Setup.bat
  8. Readme.doc and other doc files: any last-minute information that is not contained in the manual. Please read these files before installing or using CARD.
  9. Other miscellaneous files, mainly for installation.

Note: all CARD files have been checked for computer viruses using Symantec's AntiVirus software.



This section will explain how to install CARD to a hard drive.

The download file is named CARDzip.exe. This is a self-extracting file that contains the remainder of the CARD files. To extract the files required for installation, simply run (execute) this file.

Automatic installation

CARD comes with an automatic installation program (Setup.bat). Setup will guide you through the installation process. You should not attempt a manual installation of CARD because some of the files may be compressed and therefore will not work properly.

A complete installation (including the original CARDzip.exe file and the extracted setup files) requires about 5 MBytes of disk space. If you have limited disk space, then Setup allows a limited installation (without the example resonators). You will be prompted during the installation process.

To use Setup, do the following:

  1. If you are installing from Windows, open a DOS window.

    a. Press Ctrl+Esc together to bring up the Windows task bar.
    b. Click on "Programs".
    c. Find and click on "MS-DOS Prompt".
    d. If the DOS window is not full-screen (i.e., if it has a title bar and border), then press Alt+Enter to produce a full-screen window.
  2. From the DOS prompt, type the following, with an Enter key after each line:

         Setup X: Y: Ydirectory

    where  X = letter of the drive where CARD's setup files reside
               Xdirectory = directory on X where CARD's setup files reside
               Y = letter of the drive where CARD will be installed
               Ydirectory = directory on Y where CARD will be installed.
                  (Ydirectory will be directly beneath the root directory.)

Ydirectory can have any name. However, the recommended name is CARDxxx, where CARDxxx is the name of CARD's executable file. (See "Distribution Files" above.) For example, if CARD's executable file is CARD900.exe, then you should name Ydirectory "CARD900".

Caution: Ydirectory should not be the same Xdirectory.

After you enter the above information, Setup automatically creates Ydirectory and copies all of the CARD files to Ydirectory. Any compressed files will be automatically expanded to their full size.

Example 1

To install CARD version 9.00 from directory CARDdemo of drive C: to directory CARD900 on hard drive D:, open a DOS window and type the following:

     Setup C: D: CARD900

Example 2

To install CARD version 9.00 from the root directory of floppy drive A: to directory CARD900 on hard drive C:, open a DOS window and type the following:

     Setup A: C: CARD900


If you find that CARD does not meet your requirements, then you can simply delete the directory (folder) in which CARD has been installed. (Note: since CARD is not a Windows program, it would not have made any changes to the Windows' Registry.)


Starting CARD

After CARD has been installed, you can run CARD from a DOS prompt. (If you are running under Windows, first open a DOS prompt window. If the DOS window is not full-screen (i.e., if it has a title bar and border), then press Alt+Enter to produce a full-screen window.) Then enter the following, with a Enter key after every entry.


where: Y = the disk drive letter where CARD has been installed by Setup.bat.
           Ydirectory = the directory where CARD has been installed by Setup.bat.

Loading sequence

As CARD begins loading, it first checks for the copy protection diskette or key. (This doesn't apply to the demo version.)

CARD then resets the printer if the printer is properly connected. This permits proper CARD printouts (not available in the demo version). Note: CARD also resets the printer before quitting so that printouts by subsequent programs will not be affected.

Next, CARD's title page (with copyright notice) appears and remains on-screen for approximately seven seconds. For the demo version, a short explanation appears.

CARD then performs some general hardware/software error-checking. If needed, status messages will be displayed before CARD proceeds.

CARD then loads several configuration (.cfg) files which contain user-definable defaults. These defaults can be adjusted from CARD's "Option" menu (Alt+O).

Main program

After the above process, the Main Menu Checklist will be displayed:

Files   Graph   Option   Equation   Help 

   Step through input checklist [1]
      Resonator type
      Tuning mode
      General requirements
      Resonator parameters
      Face cavity
   Equipment [E]
   Material [M]
Enter resonator shape (spreadsheet) [v]
Step through tuning checklist [2]
   Choose calibration material
   Choose auto-tune surfaces [A]
Set tuning parameters [T]
Set slice parameters
Slice [z]

Access "Information" to learn the general procedure for using CARD.

How to quit

You can quit (leave CARD) from most menus by pressing X or from the Exit option of the File menu. At this point you will see the prompt:

Save current file before quitting? Y/N

If you want to quit, then press N. If you would rather continue with the current session of CARD, then press Y. (Note: for the demo version, the resonator file cannot be saved.)




CARD provides two sources of help: the CARD manual and CARD's online help. The manual provides an overview and also examples of resonator design. CARD's online help provides detailed information about each of the menu options. It may also provide additional help that is not available in the manual.

General help

From anywhere within CARD, you can obtain general help information by pressing Alt+H. This will bring up the master list of topics.

From the master list, you should access "Using the help system" to understand how to use the help system. (To access a help topic, simply move the cursor to the desired topic or highlighted cross-reference and press the Enter key or double-click.) Note: unlike the rest of CARD, the mouse is active within the help system.

You can exit from CARD's help by pressing Esc until the CARD menu reappears.

Keyboard help

CARD uses certain keys for special purposes. From within CARD, press K for keyboard help. See below for a list of these keys.

Menu help

For many menus, the first option is "Information". This option gives general information about the purpose of the menu. If you are unfamiliar with a menu, you should read this information first.

If you need help about a particular menu option, first move the cursor to that option. Then press F1 to obtain help.

Results help

Some menus have both an input section and a results section (located below the input section) where the calculated values appear. For example, the "Bolt calculations menu" appears as:

   Bolt dimensions ..................... M10-1.25
   Bolt force .......................... 50000 N
   Bolt thread coeff of friction ....... 0.15
   Bolt head coeff of friction ......... 0.15

   Torque coefficient K ................ 0.20
   Tensile stress diameter ............. 8.72 mm
   Tensile stress area ................. 59.7 mm2
   Tensile stress ...................... 837.62 MPa
   Torque .............................. 101.0 N-m

To make the cursor jump between the input section (blue text) and the results section (green text), press the Ins (Insert) key. After the cursor jumps to the results section, you can move the cursor to the desired result and press F1 to get more information about a particular result (e.g., if you need help with the "Torque coefficient K" result). When you have finished in the results section, use the Ins key to return to the input section.

Spreadsheet help

In the spreadsheet, you can use the F1 key to get general information about entering the resonator shape. In addition, you can get more specific help about the indicated keys by holding down the Alt key and pressing the desired key. For instance, for help with the F2 function key, hold down the Alt key and press the F2 key. This only works in the spreadsheet.



This section describes the keys that are used within CARD.

From within CARD, press K for keyboard help. This may provide additional information.

In the columns below labeled Key, the equivalent mouse button is given in parentheses (L = left button, M = middle button, R = right button).

Bar menu keys

The bar menu appears at the top of each menu screen. To access one of the listed options, press Alt and the highlighted key together. For example, to access the File option, press Alt+F

Menu keys

The following keys are used in CARD's menus.


Key Location


F1 or ? All menus Calls help information.
Esc All menus Cancel an entry, or escape from the current menu.
(Enter) All menus Accept the current value or option.
or Space All menus Moves the cursor down to the next menu option. If the cursor is at the last option, then it will jump to the top menu option.
Up arrow All menus Moves the cursor up to the next menu option. If the cursor is at the first option, then it will jump to the last menu option.
Space Spreadsheet Changes the active surface to the previous or next surface.
Home All menus Moves the cursor to the top (first) option.
End All menus Moves the cursor to the bottom (last) option.
F9 All menus Displays the resonator shape.
F10 All menus Changes the current units (from metric to English, or from English to metric).
Alt + Num Spreadsheet Help with the surface type associated with Num.
Alt + Fn Spreadsheet Help with function key Fn, where n is the function key number.


Menu quick-access (hot) keys

The following letter keys ("hot" keys) give quick access to certain menu options. 


  1. In CARD's menus, the hot keys are shown in brackets at the right of the associated option (e.g., [E] -- the Equipment menu).
  2. The quick keys respond to either upper or lower case keys. However:
    1. Keys shown as upper case can be accessed from any menu, even if the key is not visible from that menu (e.g., [E] --  the Equipment menu).
    2. Keys shown as lower case can be accessed from the menu where they are visible (e.g., [z] -- Slice (available only from the Checklist menu.)).
  3. In the table, the menu path to the option that is associated with the hot key is shown in brackets (see the example).

Example: to access the printer setup [\Option\Setup\Printer], either:

  1. Use the hot key P (quick method):
    1. Press P (either upper case or lower case).
    2. After adjusting the required options, press Esc to exit the printer setup and return directly to your previous location in CARD.
  2. Use conventional menus (slow method):
    1. Press Alt+O (to access the bar-menu "Option" option).
    2. Access the "Setup" option.
    3. Access the "Printer" option.
    4. After adjusting the required options, press Esc three times to exit the above menus and return to your previous location in CARD.


A Set Auto-tune parameters. [\Checklist]
B A menu of standard bolt sizes.
[\Equation\Other\Bolt dimensions]
E A menu of available equipment. [\Options\Configuration\Equipment]
G A menu for adjusting how the graphics are displayed.
K Displays keyboard help.
M A menu of available materials. [\Options\Configuration\Materials]
For the spreadsheet, this displays the material corresponding the currently active surface. The material properties for this surface can be changed.
O Open (load) a resonator file from disk. [\File\Open]
P A menu for adjusting the printer parameters. [\Option\Setup\Printer]
S Save the current resonator design to disk. [\File\Save]
T Set tuning parameters. [\Checklist]
v Enter the resonator shape (spreadsheet). (Available only from the checklist menu.)
X Exit CARD. [\File\Exit]
Y Equivalent geometry [\Equations\Other\Equivalent geometry]
z Slice. (Available only from the Checklist menu.)


Help window keys

The following keys can be used when CARD's help window is displayed.



F1 Displays the master topic index.
Alt+F1 Displays the previous topic window.
Esc (R) Closes the current topic window and returns to the master topic index. If currently in the master topic index, then closes all help.
Tab Moves to next highlighted cross-reference item.
Shift+Tab Moves to previous highlighted cross-reference item.
(L) Accesses the help topic at the cursor.
Up arrow Moves 1 line toward the beginning of the help.
Moves 1 line toward the end of the help.
(Page Up)
Moves 1 screen toward the beginning of the help.
(Page Down)
Moves 1 screen toward the end of the help.
Home Moves to the left of the current window.
End Moves to the right of the current window.
Ctrl+Home Moves to the top of the current window.
Ctrl+End Moves to the bottom of the current window.
Ctrl+PgUp Moves to the last line of the help.
Ctrl+PgDn Moves to the first line of the help.


Example resonator

This section will explain how to load and analyze a simple resonator. Editing the resonator shape in the spreadsheet will not be explained.

Auto-tune length example

The resonator for this example (At-leng1.hrn) is a cylindrical unslotted 20 kHz horn with a .375" diameter stud. This horn will be analyzed in the auto-tune length mode, where CARD will automatically adjust the horn's length to tune from the initial frequency (19228 Hz) to the desired frequency (20000 Hz).

Follow these steps:

  1. Start CARD.
  2. Normally, the first time that you start CARD you should access Options on the bar menu (Alt+O) and make any required changes. This is not necessary for this example but you may wish to do this the next time you start CARD.
  3. You should access the Information option to get an overview of CARD.
    1. Move the cursor down to the "Information" option using the arrow keys or the space bar. Press Enter.
    2. Press Esc to exit from the help.
  4. Load the horn At-leng1.hrn.
    1. Press Alt+F to access the File menu on the menu bar.
    2. Load the horn At-leng1.hrn:
      1. Access the "Open [O]" option or press O (the hot-key to open a file).
      2. Type "At-leng1.hrn" and press Enter or
      3. Obtain a list of horns:
        1. Type "*.hrn" and press Enter. This will list all of the hrn files.
        2. Scroll through the list until you find At-leng1.hrn. Press Enter.
      4. The status section at the middle of the screen will show that At-leng1.hrn has been loaded. The title will show a description of this horn.
    3. Press F10 as required to change between English and metric units. The units will be indicated in the upper right corner of the screen as "E" or "M". F10 will change the units throughout CARD and can be used from any menu.
    4. You will be asked if you want to view this horn. You should generally view the horn to verify that it is the desired horn. To view the horn, press Y. (Note: you can also press Enter, since the Y is highlighted to indicate that it is the default response.) Whichever response you choose (Y or N), this will become the default (highlighted) the next time you load a resonator. If you choose to view the horn:
      1. Wait for the horn shape to be displayed.
      2. Press any key to return to the Files menu.
      3. Note: you can also view the horn from any menu by pressing F9.
    5. Press Esc to return to the Main Menu. (For all menus, pressing Esc will exit the menu and either:
      1. return you to the previous menu.
      2. take you to the next menu in the menu sequence.)
    6. Note: in the following, you should assume that the Enter key is used to access a menu option or after setting an option value.
  5. Access "Step through input checklist [1]" from the Main Menu. For this example, all of the checklist items have been correctly configured. However, you should look at the available options as you move through the menus. To leave each menu and move to the next menu, press Esc. After several menus, you will return to the Main Menu.
  6. At this point you might normally adjust the resonator's dimensions in the spreadsheet (the "Enter resonator shape (spreadsheet) [v]" option from the Main Menu). You might also adjust the material properties or set the equipment parameters (e.g., the stud dimensions, wrench flats, spanner holes, etc.). For this example, we will assume that these are already correct. Therefore, you are ready to analyze (Slice) the resonator to determine its performance.
  7. At this point you would normally access "Step through tuning checklist [2]" from the Main Menu. For this example, all of the checklist items have been correctly configured. If you access this option, choose surface 5 (the last surface) as the auto-tune length surface. For the next menu ("Tuning parameters menu"), just Esc to return to the Main Menu.
  8. Set the slice options:
    1. From the Main Menu, access "Set slice parameters". (Note: you can quickly get to this option from the Main Menu by pressing End and then the Up arrow.)
    2. Access "Slice speed" and set the value to "1" (slowest). This is done so that you can see the details of the slicing process; otherwise, you can set the speed to any available value (1 = slowest; 10 = highest).
    3. Access "Pause after each iteration". This will automatically change from "No" to "Yes". This will cause the slicing to pause when the slicing reaches the end of the resonator. At that point, you can then press any key to begin the next slicing iteration. (Note:  after you have finished with this example horn, you can reset this to "No" for faster execution.)
  9. From the Main Menu, access the "Slice [z]" option to begin slicing. Notes:
    1. During slicing, don't press any key except when the slicing pauses. Otherwise, the slicing will be aborted.
    2. Observe that each slice conforms to the shape of the resonator. For each slice, CARD calculates numerous parameters associated with that cross-section.
    3. At the end of each iteration, following will be displayed:
      1. The top panel displays a text status box. The contents of this box will depend on the chosen tuning method.
      2. The horn shape will be displayed in the bottom panel. Initially, the slices will not stop at the end of the horn; this indicates that the horn is not yet tuned. After each iteration, the slices should be closer to the end of the horn as CARD adjusts the length of surface 5; this indicates that the tuning is converging to a solution.
      3. The calculated stress curve will be displayed in the middle panel. For this horn, an approximate radius stress is also displayed. (If preferred, you could have chosen to display other parameters (such as the amplitude) from the "Main menu\Set slice parameters\Slice graphics" option.)
    4. After you have studied the results at the end of each iteration, press any key to begin the next iteration. For this horn, four iterations will be needed for the results to converge (i.e., for the resonator to be tuned to 20 kHz). Other resonators may require a different number of iterations.
  10. View the results:
    1. When slicing is complete, you will see a text summary of the results. If you press F1 at this point, you will receive a description of each result.
    2. When you have finished viewing the text summary, press Esc to view the graphical results. Note: you can only return to the text summary screen by slicing the resonator again.
    3. Graphical results: view each of the desired results.
      1. If this is a standard version (not a demo version), then you can print the Summary and Detailed results.
    4. When you have finished viewing the graphical results, press Esc to return to the Main Menu. Note: after you return to the Main menu, you will only be able to print out the results by slicing the resonator again. However, you will be able to view the graphical results by accessing the bar menu Graphics option (Alt+G).
  11. Make any required changes in order to improve the horn's performance:
    1. The horn's shape can be adjusted in the Spreadsheet. In the spreadsheet, press F1 for information on how to enter or edit the horn's shape.
  12. You should explore CARD's Equation section (Alt+E), which has many theoretical and empirical equations dealing with resonator design. In the Equation menu, access "Information" to see a tree diagram of all options. You can click on any of these options to see a detailed description.

Other examples

The following table describes all of the example resonators. The file name for each example resonator ends with a "hrn" extension. These horns are listed in the order in which they appear in the full CARD manual.



Various example horns that show how the horn shape is entered and modified in the spreadsheet. These are explained thoroughly in the full CARD manual.
Cal1.hrn Calibrate mode: A cylindrical horn with known dimensions, frequency (19877 Hz), and gain (2.47). The thin wire wave speed and gain correction factor will be adjusted until the known parameters have been achieved.
Cal2.hrn The same as Cal1.hrn, but after completion of calibration.
At-leng1.hrn Auto-tune length mode: A 20 kHz tapered cylindrical horn, frequency = 19887 Hz (per Cal2.hrn). The length of surface 5 will be adjusted in order tune to 20 kHz. This is the example that is detailed above.
At-leng2.hrn The same as At-leng1.hrn, but after completion of auto-tuning to 20 kHz.
At-thic1.hrn Auto-tune thickness mode: A 20 kHz slotted unshaped bar horn, frequency = 20435 Hz. The material has been calibrated and the menus remain as they appear at the end of calibration.
At-thic2.hrn The same as At-thic1.hrn, but the menus have been set for the desired auto-tune thickness mode. The thickness of surface 4 will be adjusted toward the middle of the slots (banding) in order tune to 20 kHz.
At-thic3.hrn The same as At-thic2.hrn, but after completion of auto-tuning to 20 kHz.
At-step1.hrn Auto-tune step mode: A 20 kHz cylindrical horn, frequency = 20222 Hz. The position of the nodal radius-step (surface 3) will be adjusted in order tune to 20 kHz.
At-step2.hrn The same as At-step1.hrn, but after completion of auto-tuning to 20 kHz.
At-gain1.hrn Auto-tune gain mode (variable resonator length): A 20 kHz tapered cylindrical horn. The thickness (diameter) of surface 2 will be adjusted in order to increase the gain to 3.63. Simultaneously, the length of surface 5 will be adjusted to maintain a frequency of 20 kHz.
At-gain2.hrn The same as At-gain1.hrn, but after completion of auto-tuning.
At-strs1.hrn Auto-tune stress mode: A 20 kHz cylindrical horn. The angle of surface 4 will be adjusted in order to minimize the stress. Simultaneously, the length of surface 5 will be adjusted to maintain a frequency of 20 kHz.
At-strs2.hrn The same as At-strs1.hrn, but after completion of auto-tuning.
Matcolor.hrn This horn simply shows each of the color-hatch pattern combinations for each of the 10 available materials. This horn should not be analyzed.



If you decide to upgrade from the demo version to the standard version, you will receive the following:

  1. A diskette containing the current standard version with all functions enabled.
  2. A copy protection diskette or key.
  3. A complete manual (300+ pages and over 40 figures) with tutorial examples.
  4. One year of free support.

To upgrade, contact Krell Engineering (see the Support section below).



You may use the following options for support.

Krell Engineering
212 E. Medwick Garth
Baltimore, MD 21228

tel/fax: 410-747-5731
e-mail: CARD@krell-engineering.com

For the standard version of CARD, free support will be provided for one year from the initial license date. For the demo version, free support will be provided for one month from the initial support inquiry.

Problem resolution

If you encounter a problem, you will receive the best support via telephone. If appropriate, you should consider e-mailing a copy of the resonator file on which you were working when the problem occurred. Printouts of your monitor screen (by fax or e-mail) can also be useful in diagnosing the problem. Please note the version of CARD that you are using and the operating system (DOS , Windows, or Windows NT version).

If you write, please include as much relevant information as possible. This will permit the quickest resolution of the problem. If you have questions about the manual, just photocopy the desired sections and write your questions in the margins. (Please write legibly.) Also, please include a telephone number and convenient time when you can be reached.

You may also want to log onto Krell Engineering's web site (above) to see if there are any suggestions related to your problem. You can also e-mail from that location.


>> All suggestions for improving CARD are appreciated. <<


Equipment requirements

Required equipment


IBM micro-computer (or true compatible) based on the Intel 80286 (or higher) microprocessor.

Operating system

Version 3.3 (or later) of Microsoft DOS. Version 5.0 (or later) is recommended for printing VGA graphics. (See below.)

Although CARD is a DOS program, it will run acceptably under Microsoft Windows. (Contact Krell Engineering for additional information.) Also, see known issues


The computer must have approximately 480 KB of free conventional memory after any other memory-resident programs have been loaded.


A VGA color display (640 x 480, or higher) is recommended. (The values in parentheses give the graphics resolution.) However, CARD will also run with any of the following displays: any video adapter and monitor capable of displaying IBM graphics (CGA, 320 x 200; MCGA, 320 x 200; EGA, 640 x 350).

Disk drives

A hard (fixed) disk with approximately 5 MBytes of free space is required. One 1.44 Mbyte floppy drive is required to load CARD onto the hard disk (not required for the demo version).

Optional equipment


A two or three button mouse may be used. The mouse is only active when the on-line help is invoked.


CARD is configured to support any printer that is compatible with the IBM graphics printer (dot matrix) or Hewlett-Packard laser. CARD expects the printer to be connected to parallel port #1.

CARD does not support plotters.


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Krell Engineering
212 E. Medwick Garth    Baltimore, MD  21228    USA

e-mail: info@krell-engineering.com