Page:Gametronics Proceedings.djvu/13

 because of one of the part-time projects on which Bill Rusch worked on after he joined the group. This was an invention of his which involved a very clever conversion of electric guitar strings tones to tones one octave lower than those of the natural string, but with the same dynamics. As you might imagine, the sound of guitar music coming out of that room next to the elevator wasn't the kind of thing you commonly hear around Sanders and helped us start some pretty convoluted rumors.

Within a couple of months, our TV Game project had made considerable progress. We had bought an RCA 17" color TV console set early in 1967 and believe it, or not, here we were fully ten years ago, playing chase games, target games and a little later on, the first fully interactive Ping-Pong and Hockey games, with color and FM sound through the TV set. Even our earliest Ping-Pong games were played against a green background, while, naturally, Hockey was played against a background of blue ice.

While I am on the subject you might be interested in how we handled color signal generation back then. I imagine some of you are working on color right about now. So let me break into the story for a minute and do just that. What we did was extremely simple and took one NPN 6 1/2 cent transistor, 2 diodes, a few resistors and capacitors, and a 3.58 MC chroma crystal and a 15 cent oscillator tank coil. With these parts we built the chroma oscillator and thru the use of a center-tapped secondary on the tank coil we obtained two 3.58 MC signals 180° out of phase with each other. Taking an output from one side of this secondary and gating it into video with horizontal sync pulses gave us an adequate approximation to a color burst reference signal. Then we connected an RC phase shift network across the secondary outer terminals, the resistor being a potentiometer, so that the phase at the junction of the resistor and capacitor could be varied nearly 0 to 180° with respect to the color burst reference phase. Then we used horizontal sync to gate out this new phase signal via the second 3 cent diode, again into video, and presto we had background color; there was also some color fringing around the paddles and the ball that sort of came along for free and looked pretty attractive, so we left it alone.

Going back to our sixth floor lab, we find Bill Rusch who has meanwhile moved his desk in there and is grinding out ideas by the yard. Pretty soon we had some very complex game actions underway. They were all done in discrete components, which may seem strange, but isn't really, when you remember that this was 1967. At that time the only IC's available were DTL, and RTL and high speed MECL. The average cost of an ordinary multiple gate device was well over a dollar in large quantities and IC power consumption was such as to preclude their use in battery operated Home TV Games. We kept an IC design effort going for a short while but got pretty unhappy with it and left that design approach to posterity. It was just too hard to beat discrete designs built out of nickel transistors and 3 diodes so we didn't give it another thought and ploughed ahead.

Ralph Baer receives Gametronics award for pioneering work in TV game design from Jerry Eimbinder, Publisher of Electronic Engineering Times.