A structured graphics language: Ceemac. (evaluation) Ed Jackson.

A Structured Graphics Language

The best thing I can say about Ceemac is that I never bought a piece of software for so little that was worth so much. It is not easy to find. You just have to run across an ad. Brooke Boering, the author, is operating on a shoestring at this time. His ads are one inch classifieds.

How then, you might ask, did I happen to buy Ceemac? Well, Mr. Boering had a marketing idea that was a combination of sheer genius and audacity. He made a demo disk of the kind of graphics that Ceemac is capable of creating, supplied it to computer stores, and asked them to give copies free to their customers. That was my introduction to Ceemac.

I was enchanted with that demo and would have paid the $40 he asks for Ceemac, for the demonstration disk alone. The demo disk holds 35 scores, as the author calls his programs. At the touch of a key, the display changes from one dazzling display to another. On disk you find a series of programs which describe the various scores; the company, Vagabondo Enterprises; and Arthur, the language with which these text programs were created.

For your $40, you get a diskette and a manual--not a tutorial, but a manual. It suggests that you take one of the many demonstrations and experiment with it-- learn by doing.

Ceemac is not a utility to aid you in the creation of hi-res graphics using the standard Apple commands. It is a stand alone language complete with pre-defined variables, macros, line editor, commands, and error messages. It is a structured language. You do not enter program line numbers. (Nor does Ceemac. There are no line numbers.)

It points out syntax errors by placing the cursor at the beginning of the blunder, and beeping once. If the editor cannot detect the error until execution, it immediately lists the program, gives an error message, and places a prompt on the offending line.

Using The Program

What you create is not always what you set out to create, but it is always stunning in its beauty and speed of execution. You can make a paddle control the speed, or make it control a variable. You can use the buttons to start fresh, to change the color of your drawings, or to change the background color. These changes occur very rapidly.

Editing possibilities include upward and downward scrolling, list from the top, delete, replace, insert, or edit a line. All of these commands are started with only one key.

The only control characters are control-a for moving from edit to execution, and control-c to move to DOS mode.

If you are familiar with Applesoft, some of the commands will seem familiar. These include GOTO, GOSUB, FOR, and AGAIN. If you forget, type NEXT, the editor forgives you and immediately replaces it with AGAIN. Commands that are different from Applesoft and Integer are nupool, rndcol, nxtcol, spline, forcel, adot, and setasp. Among the things you can do with these commands are: set the symmetry of the pattern, setup a ratio between x and y coordinates, set xscale and yscale and rotation, and draw shapes. Ceemac does not have a shape generator. There are, however, instructions for creating shape tables.

There are also many commands unique to Ceemac. For instance, "sky,' gives you a sky, complete with number of stars you want, in any color you want, instantly. And "abox' draws boxes, rectangular or square.

You can create sounds with Ceemac or have music from your cassette control the graphics. You also have a "trace' function, and the command that I think is the cleverest of all, is. If you type x1 = x1 % 5, x1 will increment itself to the edge of the screen and then decrement itself back down. And vice versa.

Another great feature is the printer option. By keying in shift/printer slot, you can print out your own scores, or the ones on disk to study. You can also get hard copy from any of the text files.

I believe that the manual was not designed as a tutorial for three reasons: one, Mr. Boering wants you to experience the thrill of discovery and the joy of accomplishment; two, a tutorial which fully explained all the possibilities of Ceemac would probably put the cost of production out of the shoestring category; and three, too detailed explanations would stifle your creative and experimental instincts. I believe that the limitations you encounter will be your own, not Ceemac's.

About The Author

I could fill many more paragraphs with more features, but I prefer to close this with a word about Mr. Boering. When I ordered Ceemac, I said that I hoped it was user-friendly as I was pretty dumb. You can imagine my surprise when I got my check back with a personal letter from Mr. Boering, saying that Ceemac was not for everyone, and that it took some understanding of programming techniques to use. I quickly re-ordered, thanking him for his concern, and quite quickly received my disk and yet another very kind letter.

Ceemac is a fine disk for learning and enjoyment. It sets a very fine example of excellent programming, business ethics, and advertising that larger companies would be wise to imitate.

Photo: Sample output from a Ceemac program.

Photo: Figure 1. Sample Ceemac program from the demo disk.

Products: Vagabondo Enterprises Ceemac (computer program)