Release Date: December 1991 Distributed by: European Contact: ************************** *========================* * * | | * Binary Triangles * | Stephan Hoynigg | * 4940 Alzeda Dr. * | Wittgensteinstr.117 | * La Mesa, CA 91941-5721 * | 1238 VIENNA | * USA * | AUSTRIA | * * | | * Phone (619)-579-3042 * | Tel: 011-43-1-88 63 85 | * FAX (619)-579-0216 * | FAX: 011-43-1-88 63 85 | ************************** *========================* This tutorial covers the subject of Decision Tables from their basic foundations up into recent developments in decision table theory. The purpose of this tutorial is to explain: (1) what a decision table is, and (2) how to use decision tables to help design software logic where complex decision procedures are involved. There is NO complex math involved in, or required for, this tutorial. The DEVA programs are only recently introduced. Up to now, not very many people realize how powerful they are. To learn how DEVA-PRO helped one person with his logic design problem see the section at the end of this READ.ME file titled 'A Moment Of Enlightenment'. REQUIREMENTS This tutorial requires an IBM PC/XT/AT or compatible with DOS 2.1 or higher. If you do not like the way the TUTORÄD.EXE program works then use its' key to export a tutorial '.EDO' file to an ASCII '.ASC' file which can be printed or viewed with your favorite editor or word processor. HOW TO RUN THIS TUTORIAL PROGRAM This tutorial will run from a diskette in the [A:] or [B:] drive. Enter to start the tutorial. The TUTORÄD.EXE program will load as much as possible of the tutorial file into high memory. The tutorial operates quickly after it is loaded into high memory. If your computer does not have enough high memory to hold all of a tutorial file, then from time to time a different segment of the tutorial file may have to be loaded. Whenever a tutorial is being loaded into high memory a message is displayed. These tutorials will run from a floppy, but you may find that running them from a hard or RAM disk is preferable. Tutorial load times from various drives: 105 seconds [A:] or [B:] floppy drive 11 seconds [C:] drive (hard disk) 5 seconds [D:] drive (RAM disk) I mention these load times because the one minute & 45 seconds it takes to load the tutorial from a FLOPPY is a long time. The reason it takes so much time is that the file it is loading into high RAM is a large file (about 250K bytes) and floppies are slow (this is why I recommended that you run the tutorial from a hard disk, or even better, a RAM disk). If you have an earlier edition of 'TUTOR-D.EXE' delete it and use this edition. A FEW WORDS ABOUT THE OPERATION OF THIS TUTORIAL This tutorial is easy & intuitive to operate! If you just guessed which keys did what you'd probably get most of them correct! The first several screens of this tutorial contains information about its' operation. If you want to skip these introductory screens then switch to the Outline Mode with the key and move to the screen where you want to start reading. Below are a few thoughts to orient you to the use of the TUTORÄD.EXE program: (1) This tutorial is screen oriented (it presents one screen-full of information at a time). (2) The screens are organized like an outline. They have a numerical order and an indentation number. This makes it easy to either skim the tutorial or to go into more depth on a particular topic. (3) There are TWO modes of operation for this tutorial: (A) the Tutorial Mode {shows a screen full of information}, and (B) the Outline Mode {shows outline headers only}. The outline headers in the Outline Mode might look like this: 0 Screen # 0 1 Screen # 1 .2 Screen # 2 (Note that this screen is indented) ..3 Screen # 3 (This screen is even more indented) 4 Screen # 4 (4) Some TUTORÄD.EXE command keys are listed below: * The key always exits the tutorial program. * The and the keys both do exactly the same thing. Both take you down to the next screen at the same level of outline indentation. This means that you might skip over some indented screens that contain more detailed information. For example: if you were at Screen # 1 (shown above) and you pressed the or the key, then you would go down to Screen # 4 (skipping over screens # 2 and # 3 because they are at a more indented level). * The (or the <+> key) takes you to the next screen regardless of its' indent level. For example, if you were at Screen # 1 and you pressed either of these two keys, then you would go to Screen # 2 (the screen that immediately follows Screen # 1). * The takes you back to the previous (higher) screen that you have viewed. This key lets you RETRACE your path. * The takes you to the next LESS indented screen (if there is one). For example, if you were on Screen # 2 and you pressed the key you would go down to Screen # 4. * The <-> (minus) key and the <+> (plus) keys take you backward or forward one screen (regardless of indent level). * The key always takes you back to the first screen. * The key always takes you to the last screen (to the end of the tutorial). * The or keys toggle to/from the help screen that summarizes all the program control keys. * The key will export a screen or an entire file to an ASCII file. * The key (as in olor) allows the round robin selection of 7 possible screen palette's. If you don't like any of these screen colors consider using the key to turn the tutorial into an ASCII file. Then you can print or look at the file with your favorite word processor or text editor. The last round robin selection strips all the blinks and colors off the screens. Use this selection if you don't like any of the color selections. (This may lose a little information on a few screens where colored lines or hilites are used to bring attention to various details). When you exit the tutorial you may return the screen to its' original color with the command. * The key (as in ocate) allows you to locate an exact phrase (up to about 45 characters long). The key only works in the tutorial mode. It does not work in the Outline Mode! This is a wrap-around search. It always starts at the top of the current screen and then looks at successive screens until it gets to the end of the tutorial. Then it wraps-around to the start of the tutorial and continues looking until it gets back to the screen where the search was last started. While the word "Looking" is flashing at the bottom of the screen you can press any key to stop the search and return to the screen where you last started the search. When the phrase you are looking for is found that screen is displayed with the cursor at the start of the phrase. Then 3 options will be shown at the bottom of the screen (as follows): ore = , estore, or iew = . The or continues the search. The key stops the search and restores the screen where the search was last started. The or key stops the search at the current screen. * The key will lip (flick) the screens past you in either a forward or a backward direction. This is like thumbing through the pages of a book. You can stop the flipping by pressing the key. The speed of the flipping can be adjusted with the <+> (faster) and <-> (slower) keys. THE KEY IS USEFUL TO RAPIDLY GLANCE AT ALL THE SCREENS OF A TUTORIAL. * The key is the jump/toggle key. This key allows you to jump to a particular screen and then toggle back to the screen that you jumped to it from. If you press the key once you will be prompted to enter the number of the screen you want to jump to. If you don't enter a number but just press the key again, then you will toggle to the screen number that you previously entered. As long as you don't change the number of the screen to jump to you can move to other screens and still jump to the selected screen and then toggle back to the screen you jumped to it from. THE KEY IS USEFUL WHEN THERE IS A SCREEN YOU NEED TO REFER TO FROM A NUMBER OF DIFFERENT SCREENS. * The

key toggles back to the product description screens where the products that Binary Triangles offers are listed and described. If you press the

key a second time it will toggle back to the screen you were looking at when you first pressed it. USE THIS KEY WHENEVER YOU WANT TO FIND OUT MORE ABOUT THE PRODUCTS OFFERED BY BINARY TRIANGLES. Some people have taken exception to the colors used on the screens of this tutorial. I don't particularly like them either but I had trouble finding color combinations that were readable on a wide variety of video monitors. I have three different video monitors and no one color setting is totally visible on all three. So I have tried to provide enough selection of color palettes that you can read the screens no matter what kind of monitor you have. If none of the color palettes are suitable for your monitor then refer to the use of the key. If you find a typo in my tutorials, or some place where I said 'left' where I should have said 'right', or if my thoughts were not clear or did not make sense to you, then please note down the screen number and notify me. I hope you find these tutorials both informative and interesting! FEEDBACK - If you don't tell me I won't know A man reported that his '386 S16 DOS 5 Quantel Bios' computer gives an 'Out Of Stack' message and locks up when he tried to run the DEVAHELP.EXE help screen program (this has nothing to with the DEVA programs proper which are written with a different compiler or with the tutorial programs). He also reports that the DEVAHELP.EXE program runs perfectly on his other computer. The DEVAHELP.EXE program may have a problem with that one particular system at this point in time. I'm looking into it. This is the only problem that has been reported to me so far. I have been told that the interface of the DEVA programs (where you select the path and the file) are primitive because they do not have point and shoot mouse features. I agree! In the future this should be improved. However, do not judge the book by its' cover. The real power of the DEVA programs lies in the work they do with decision tables, especially standardizing, simplifying, and designing complex logic with them. Even though the interface of the DEVA programs is very plain, it is still quite servicable as it now stands. Sincerely, Wayne Lill Jr. A Moment Of Enlightenment This true story was told to me in a phone conversation by a person who had recently bought DEVA-PRO. This person had been working with one of his clients for about a year trying to come up with a logic design that the client would approve. But the client kept changing his mind about exactly how he wanted to handle the problem and they could not seem to come up with a logic design that really did the job. Then this person bought DEVA-PRO and set up the problem with a decision table. The logic measure of this first decision table was about 150 (which is a fairly large table). The person started simplifying the decision table and was able to make many additional improvements to the logic design as the logic was presented in simpler and simpler flowcharts. The logic measure dropped from 150 down to 100. Then it dropped down to 59. When the logic measure dropped to 51 this person experienced a light bulb going off in his head (a moment of enlightenment), and all the pieces of the logic design problem fell into place. Within a few days he had finished coding the program! Fast work, but that's how it can go with DEVA-PRO. I do not claim that all your logic design problems could have as dramatic an end as this one if you use DEVA-PRO. Probably some of them would, and some of them would not. You never know until you try! My experience with simplifying decision tables gives me the impression that on the average I experience a 30% reduction in the logic measure with the first simplification. Some tables get more, other tables get less. But say that you get a 30% reduction in the complexity of your logic, then it is highly likely that you will be able to see how to improve that logic in various ways now that you can better see what it is really doing. The improvements are usually of two kinds: (1) eliminating subtle bugs and errors in the logic that you might never been able to find by any other means, and (2) being able to think up better concepts to describe the logic design problem you are working on. Both of these kinds of improvements tend to lead to simpler logic for the simple reason that both bugs and inferior concepts tend to make the logic design unduly complicated. DEVA-PRO finally gives you a way to combat complexity. There is no other program like DEVA-PRO. DEVA-PRO is a program that can really make a difference to your logic design efforts.