chapter 1


Rod leaned slightly forward, his eyes intently fixed on the screen before him. He pressed a small pen to the surface of a special digitizing table sitting in front of the computer. On the screen appeared the image of a logic element used in circuit schematics. As he moved the pen along the surface of the table the logic gate element floated out of the menu area and followed his movements on the screen, just as if the gate had been “captured” or hooked by the pen. The logic gate could be moved anywhere on the screen by his simply tracing the pen across the table. Amazing!

Next, when Rod had seemed to find the right place for the gate, he pressed the pen down gently on the table and the gate froze in place on the screen. Rod moved another gate up from the menu area and placed it next to the first. Rapid movements followed and soon wires appeared connecting the gates together. Finally the schematic diagram of a flip-flop circuit emerged on the screen, complete with lines indicating inputs and outputs in proper sequence.

Rod leaned back. A satisfied grin spread across his face as his partner stared wide-eyed in disbelief. “I see it but I don't believe it,” his partner said.

Fig. 1-1 shows what Rod's partner had witnessed: the creation of a complex schematic diagram on a low-cost graphics computer. What made this schematic special was that no paper was ever used, no erasers, no whiteout, no ink, and no cutting. Everything was done on the screen of a low-cost computer. A special digitizing table allowed Rod to input his movements to the computer. A program in the computer created the logic elements on the screen and allowed them to be moved from a menu area into a drawing area, then fixed there while wires were drawn from one point to another. A logic element could be rotated and moved elsewhere in seconds. Erasing was possible by simply reversing the drawing color to black.


(A) Setup of equipment. (B) Closeup of display screen. Fig. 1-1. Creating schematic diagram by computer.

Sound like the future? Well it's not; in fact this very system can be purchased today, complete with drawing and design software, for under $1500. And you can learn to use it in less than an hour.

This book is about this and other aspects of the latest hobby and consumer market to sweep the nation—personal computer graphics, a new form of visual experience that utilizes low-cost personal computers in ways never before dreamed of.

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