Here's what I remember about Executive Games:

I was hired to do board-level repair on their TV tennis game. I ended up not only doing the repairs, but also running the repair department which was four to five people besides me.

The game electronics were designed mostly by Glen Dash. I believe that he was still an MIT student at the time, working in MIT's "Innovation Center". The mechanical design was done by one of Glen's fellow students. I didn't have as much daily contact with this fellow, and can't recall his name. There was probably some kind of licensing agreement between Executive Games and MIT, but I never knew the details.

Executive Games was owned and operated by the Stepanek family. I think the president was Peter Stepanek. His two sons worked with him. The family ran another business from the same space, making canvas tote bags. I believe that company did business under the name "Totes".

Keep in mind that the electronic game business was in its infancy, and that there were no trade-specific magazines, retail outlets, etc. The only trade show that was applicable was Toy Fair; I'm almost certain that's how Executive Games introduced their products.

The Stepaneks took advantage of their distribution channels for the tote bags. They sold totes to many of the large department-store retailers. This gave them the connections they needed to get their TV tennis product into the big stores.

The factory was located in the old Bakers Chocolate building in Milton, MA. My "office", shared by the four or five techs I supervised, was an enclosed bridge above the alley between two buildings. Occasionally a trailer truck just an inch or two too tall would scrape beneath the bridge, and everything would shake up and down. There was no heating or air conditioning in that space, so we ran lots of space heaters in the winter and lots of fans in the summer.

Executive games made a big splash with the TV tennis game, which was the first such game to retail at under $100. This was either the Christmas season before Atari's Pong hit the stores, or Pong started at a higher price point - I'm not certain about the details. Regardless, Executive Games did OK that first season.

For the second season, Executive Games developed a TV Hockey/Soccer game. This was a two-player console with a built-in X-Y joystick and a button for each player. The button was used to "carry" the ball (puck).

There were a lot of companies in the TV game console market, and one hurdle they all had to overcome was getting FCC approval for their RF modulators. Since Executive Games had successfully accomplished this feat for two products, they sold their services to other game manufacturers. Glen Dash would take an untested game, bring it into the lab and perform the same tests that the FCC would perform. He'd make modifications as necessary and tell the manufacturer how to change their design to pass the FCC testing. This was invaluable, since each attempt at FCC approval could take months. Being able to go in the this first time with a product that met FCC requirements saved time and ensured that the product would not miss the narrow window for Christmas sales.

Executive Games folded shortly after that second Christmas season. At the time, I was working in the MIT Innovation Center lab trying to find suitable materials (focusing on conductive polymeres) to design a low-cost, reliable X-Y joystick replacement for the TV Hockey/Soccer game. One day, I got a call from Glen saying that the factory had been vandalized the previous night and that the Stepaneks would be closing the business soon.

The technology behind both games was very similar. These were analog/digital hybrids. There were about 25 to 30 14- and 16-pin chips and a couple handfuls of discrete resistors, capacitors and transistors on each circuit board.

As best I can recall (I didn't take schematics with me when I left) the digital logic was used to generate the TV horizontal and vertical sync timimg. There was something unusual about that timing chain; I'm pretty sure that the horizontal frequency was derived from the line frequency by some kind of poor-man's PLL circuit. Composite sync was generated using summing resistors at the outputs of the timing chains.

The digital circuitry was built from SSI/MSI chips - basically gates and counters - on two-sided PC boards. I'm pretty sure that the original production runs used 74LS-series chips and later runs adopted CMOS, probably a mix of 74C- and 4xxx-series. This was a quarter century ago, so I'm really not certain about the details.

The player and ball were generated using analog window comparators. A window comparator's output is "on" when the input falls between a high threshold and a low threshold. Object position was determined by dragging the pair of thresholds to higher and lower voltages while driving the comparator's other input with a voltage ramp synchronized to the horizontal or vertical sweep. A pair of window comparators was used for each object - one comparator for the vertical bounds of the object and the other for the horizontal bounds. (Actually, that's probably true only for the ball position on TV Tennis. I think the horizontal positioning of the tennis players must have been generated digitally. But on TV Hockey/Soccer where the players had two degrees of freedom, they had to use window comparators for both axes.)

Player position was generated by the hand controllers on TV Tennis - these were a simple voltage divider that moved the comparator's window to a higher or lower voltage depending upon the position of the potentiometer in the controller. On TV Hockey/Soccer, the principle was the same. However, there was an additional RC integrator that added a lag between motion of the joystick and motion of the player on the screen to give a feel of inertia to the player's movement.

The consoles connected to the TV set using an external pod. A cable carried power and video to the pod. An RF oscillator tuned to channel 3 or 4 (approximately) was modulated with the video signal and coupled to the antenna terminals of the TV through a switch that selected either the game or the customer's normal antenna. The pod was also designed by Glen Dash, who later turned it into a construction project for one of the electronic hobbyist magazines.

Neither game console played sound through the TV. Adding an FM modulator for the sound would have been prohibitively expensive. Rather, a small speaker mounted in the console itself played "pings" gated from an appropriate tap on the timing chain.

I wish I remembered how hit detection was done. Like everything else in that circuit, it was friendishly simple. I think there were simply AND gates attached to the player and ball outputs. If both the player and ball were "on" at the same time, they had to be generating video at the same spot on the screen, thus there was a collision between the objects.

The effect of a hit detection was pretty simple. In TV Tennis, it reversed the input to the integrator for the ball's horizontal position, causing it to reverse direction on the screen. There was some clever bit of circuitry that affected the ball's vertical motion depending upon where it hit the player vertically, but I don't remember how that worked. TV Hockey/Soccer behaved similarly, but there was an added button that would slave the ball position to the player position allowing the player to "carry" the ball.

Finally, there were a pair of seven-segment LEDs on the console for scoring. This was cheaper than generating on-screen characters with the technology of the day. I don't recall how a goal was detected - it was probably another analog comparator. A goal bumped the score counter for the appropriate player and reset the ball position for the start of the next round.

I hope this helps. If you can locate anyone who still has schematics from those consoles, I can refresh my memory and offer a more accurate and complete explanation.