Visicalc made easier. (evaluation) L.L. Beavers.
VisiCalc Made Easier
I once plopped a coworker down in front of an Apple, handed her the Visicalc manual, and said something like, "Here, learn this--it's easy.' I lied a little. As good as the Visicalc tutorial is, it is really not that easy. But with Cdex, learning Visicalc on your own is definitely made easier. Cdex won't teach you advanced Visicalc techniques, but it should take you from Visi-innocent to competent user in a few hours.
Not Like a Book
The Cdex program comes on three diskettes, each of which presents a series of brief lessons. You need not take them in the recommended order, but the progression appears carefully planned, so you probably should. Also encased in the Cdex box is a small three-ring binder containing a 62-page manual. The manual is organized into three tabbed sections: Visicalc command reference, examples of seven Visicalc worksheets, and exercises.
Using Cdex is not like working through the Visicalc tutorial. This program is much more than a book displayed one monitor screen at a time. Text, graphics, and sound are all used--and used well.
The type font used in the text displays is large, easy to read, and pleasant to look at. The displays were designed by someone who understood how to use layout to communicate. There are no gaudy flashing or inverse characters to detract from the readability of the display, but the important points are clear at a glance.
The graphics are equally well done. The graphic displays are of two basic types. One is a very nice picture of the Apple keyboard (with a couple of characters missing--more about that later), to help you find the keys important to Visicalc. The other is a slightly shrunken image of the Visicalc display screen. This enables Cdex to show you what happens on the Visicalc screen when you type a command. What you see unfold on these displays is very close to what you will see when you try the same commands with Visicalc. The main difference is that events are slowed on the Cdex displays to give you time to see what is happening. The text accompanying these graphics points out what to look for, sometimes with the help of flashing arrows pointing to a particularly important part of the display.
Cdex uses sound most effectively to alert you to watch the screen for some important event--just before the Visicalc graphic is to change, for example. Sound is also used to reward right answers to questions (happy beeps--TERRIFIC!), and to alert you to errors (not-so-happy beeps--NOT QUITE). The sounds used are not overly intrusive, though some may find the happy beeps a bit heavy handed.
Text, graphics, and sound are not only well handled individually, but they are well integrated. When something is about to happen on the Visicalc facsimile, text appears alerting you to what is about to happen. Then you press RETURN or type a command, you hear a beep, and you see the event take place on the same screen. Then more text may be added for emphasis. All of this is usually done without the discontinuity and annoying delay of erasing and reprinting the screen.
A Cdex session begins with two title screens, the second of which asks for your name, followed by a main menu. I have reproduced the menus for the three diskettes as Figures 1, 2, and 3. Each menu item is a lesson on a particular Visicalc topic.
Lessons generally begin with a brief review of relevant prior material, continue with a series of instructional screens, and end with a test question and suggested exercises. Throughout this process, user input seems to be extremely well error-trapped. Pressing RESET causes the disk to re-boot, but I couldn't cause the program to end abnormally in any other way. Generally, responses not in the set of possibilities are ignored and do not appear on the screen.
The series of instruction screens presented for each menu topic contains the real substance of the lessons. I found them generally to be clearly and concisely written, well paced, and accurate in their representation of the behavior of Visicalc.
For instance, the replicate command (/R) is probably the most conceptually difficult of the basic Visicalc commands. Cdex handles it in two lessons, one devoted to the concept and the other to the procedure. Take a look at Figure 4, which shows a review screen from the "Replicating--The Concept' lesson.
That's nice, lucid review of the idea. It follows a series of other nice, lucid explanations, which together communicative very well the power and use of the replicate command.
Of course, there are a few places in the Cdex training program in which I think that the explanations are unclear or contain errors. I have compiled the ones I found in a "Quibble List' contained in the sidebar. Those evaluating Cdex for purchase should find it easy to scan this list and form their own opinions of the seriousness of the problems. Those using the programs should find some useful clarification in the list. In my opinion the quibbles listed don't significantly impair the usefulness of the program.
After Cdex presents the instruction screens, it asks one test question. Since each lesson covers a relatively small subject, and since the instuction screens often include some question-and-answer interaction, one question seems to be enough.
The question screen offers options other than the obvious one of entering the answer. You can ask for a hint, you can review that material in the lesson, or you can skip the question entirely. The hints seem to offer a good compromise between giving too much information and giving no help at all. The review option simply restarts the series of instruction screens over again. This review process can be frustratingly slow if all you are looking for is one item of information.
I think that the best feature of the quiz routine is its error diagnosis. Errors that show inadequate understanding of some part of the lesson are greeted with a message clarifying that point. For example, in Visicalc if you want a cell to have the same value as that in cell B5, you must type +B5 to specify the value reference. If you omit the + and simply type B5, Visicalc treats it as a label (which has a zero numeric value) because the first character typed was alphabetic. When Cdex asked me a question about this, I intentionally omitted the plus sign. The program told me that I had forgotten it, reminded me of why it was important, and invited me to try again. Very nice.
At the very end of each lesson is a screen directing you to the Cdex manual for a guided practice session with Visicalc. You can skip this exercise, but I suggest that you take advantage of it. There is nothing like hands-on experience to show you what you don't know. The exercises are short, and worth the time.
Cdex and the Visi-Innocent
I have used Visicalc extensively, so I am hardly a typical customer for the Cdex program; but my wife is. As a lending officer for a major bank, she does a great deal of financial analysis. Visicalc is well-suited for that kind of work, but she has never had a chance to learn it.
Predictably, her reactions to Cdex were a little different from mine. First there were matters of taste. Cdex starts each session by asking your name. My wife felt this a bit childish, so she gave it a scatological response. I recommend that everyone try this at least once--some of the resulting Cdex messages are hilarious. She also felt that the use of sound to indicate right answers was "dumb.' ""Correct' would be sufficient,' she said.
She found the delay in drawing graphic displays sometimes annoying, but agreed that the graphics were well done and informative. She also pointed out some ambiguities that I had overlooked. They appear in the Quibble List.
She liked the organization of the program in small segments, pointing out that people using it in an office environment would be subject to interruptions. But this makes the ability to review the instruction screens rapidly even more desirable, and its absence more irritating.
Overall she thought Cdex a "good program.' More to the point, she was able to acquire a practical working knowledge of Visicalc in about six hours. These hours were not in a single block, but were scattered over a one-week period, just as they probably would be in an office environment.
I agree with her evaluation--Cdex is a good program, and a very good value for its $49.95 price. It should be very useful to those who need to learn the fundamentals of Visicalc. Having someone available to answer questions might be useful, but I think Cdex is easily good enough to stand alone if necessary.
Cdex is not (and does not claim to be) a substitute for reading and understanding the Visicalc manual. I suggest a careful reading of Part III (Visicalc Command Reference) of the Visicalc manual after completing the Cdex course. You will not then be a sophisticated Visicalc user--that only comes with experience--but you will have a solid foundation on which to build sophistication.
Below are some quibbles I have with the Cdex program. These quibbles fall into two broad categories: misleading or inaccurate statements regarding Visicalc, and unclear or ambiguous instructions. I have organized these in a rough order from most to least serious. I don't think that any of these problems, or even all of them taken together, is serious enough to significantly damage the usefulness of Cdex as a training tool--which is why I call them "quibbles.'
Graph Format (/F}
Cdex says that Visicalc rounds decimal numbers to integer values to determine the number of asterisks plotted. Actually the program truncates (Visicalc manual, p. 3-20).
The conventional way of resolving formulas uses a "hierarchy of operations'--multiplication and division operations are performed first, then addition and subtraction operations. For example, in Basic the statement PRINT 2+4/2 would give 4. Visicalc doesn't work that way. It resolves formulas from left to right, so that the formula 2+4/2 would give a Visicalc result of 3. Many Visicalc users expect the hierarchy of operations to be obeyed. Cdex should have alerted them that Visicalc behaves more like a hand calculator than a computer program in this respect. Worse, Cdex does not mention the function of parentheses in grouping terms (see pp. 2-69 to 2-70 and 3-72 in the Visicalc manual). I consider this important enough to label it an inaccuracy--by omission.
According to Cdex, when you are loading a file from your storage disk (/SL), the Visicalc screen must be clear. Actually, Visicalc has no such requirement, and if you adhere to it you will lose what overlaying capabilities Visicalc has (see pp. 3-60 to 3-61 of the Visicalc manual).
The Cdex graphic display of the Apple keyboard does not show two of the characters needed for Visicalc applications. One is the circumflex ( ), which Visicalc uses to indicate exponentiation, and which is typed as SHIFT-N. The other is the @, which Visicalc uses as the first character of all function references, and which is typed as SHIFT-P.
File Deletion (/SD)
In its discussion of the command to delete a file on the Visicalc storage disk, Cdex says that after the command is completed you can change your mind and resave the sheet with /SS. That is true if the sheet on the screen is the same as the file that was deleted. Visicalc will let you delete any file on the disk, and if the one you delete is not the one on the screen, the deletion is final.
Cell As Third Dimension
Cdex discusses a cell on the Visicalc worksheet as having "depth' and as giving Visicalc a "third dimension.' I think this obscures a simple idea: a cell is just a place on the worksheet into which you can write a label, a number, or a formula.
Cdex has only a rather oblique reference to a common Visicalc problem, "If you reference a cell that Visicalc has not yet calculated, an error may occur.' This is called a "forward reference' in the Visicalc manual (pp. 2-63 to 2-64), and it is an important source of error--especially for inexperienced users. Cdex also mentions the Visicalc commands to change the order of recalculation (/GOR and /GOC), without telling you why you would want to do such a thing. Avoiding forward reference is the reason (see pp. 3-22 through 3-25 of the Visicalc manual).
Printing a worksheet is one of the more complicated Visicalc functions, primarily because of the differences among printer configurations. One of the Cdex screens says that a setup string is used for producing special effects on the printer. Since those "special effects' include printing anything more than 40 characters on a line, the setup string may be essential to effective use of your printer. The Cdex manual notes this possibility (p. 12) and refers you to the Visicalc manual for details (I suggest pp. 3-40 to 3-48). If you read that section of the Visicalc manual, you may also notice that the Cdex discussion of the /PP option is not entirely correct. Cdex says that you must specify the slot number of the printer interface if it is any slot other than 1. According to the Visicalc manual, /PP causes Visicalc to output to the lowest numbered slot containing a peripheral communications card--not necessarily slot 1. You would have a problem typing /PP if you had an inactive peripheral on a lower-numbered slot than the one the printer interface is in, so you are better off to develop the habit of typing the printer slot number rather than /PP.
The way the Visicalc functions are categorized on Cdex Disk 3 is not particularly clean. One of the categories is "List Functions,' which is said to include @ SUM, @ MAX, @ MIN, @ COUNT, and @ AVERAGE. From the name of this category and the functions in it, you might conclude that these are the functions that accept lists of Visicalc cells as arguments. But some of the logical functions do too (@ AND and @ OR), as does @ CHOOSE. Also, while we're on the subject of functions, Cdex says that the result of the @ MAX function is the "identity of the largest value.' Actually, Visicalc just returns the largest value. What's the "identity of' 4?
On Cdex Disks 1 and 2, the final screen of each lesson directs you to an exercise outlined in the Cdex manual. The directions presented on that final screen are out of order. Item 2 tells you to read and follow the printed exercise. But the printed exercise begins with the statement, "A blank Visicalc worksheet should now be showing on your screen.' Item 3 on the Cdex display screen tells you how to boot the Visicalc disk, and so produce that blank worksheet. The printed instructions preceding the series of exercises in the Cdex manual also tell you how to boot Visicalc, but some users might still find the sequence on the display screen confusing.
Table: Figure 1. Cdex Menu
Table: Figure 2. Cdex Menu
Table: Figure 3. Cdex Menu
Table: Figure 4.
Products: Cdex Training for Visicalc (computer program)