General Instruments Video Game Chip Rides Again

Early video games like Pong were not computer-controlled. They used discrete logic to generate the TV signals. As you might expect, the market exploded when you could get all the logic on a chip. Many of those games used the General Instrument AY-3-8500-1 chip, and [Jeff Tranter] shows us the chip and the many different yet similar games it could play. You can check out the retro gameplay in the video below.

These were marvels of their day, although, by today’s standards, they are snoozers. All the games were variations on a theme. A ball moved and hit paddles, walls, or goals. A few available light gun games were rarely seen in the wild because they took extra components.

The datasheet shows how simple the device was. Two CMOS chips and a couple of transistors put you in business. [Jeff] built his own board using the device, which is, of course, no longer made, but still available on the surplus market. It is great to see how simple this chip makes it.

You may not remember General Instruments, but they started the PIC chip and still exist in some form as part of ARRIS, which was spun off from Motorola and later bought by another General Instrument spinoff CommScope. General Semiconductor is another part of the brand that still operates.

We’ve seen this pulled off before, both with real chips and emulated chips. If you want to see what hardware goes into a Pong game and even simulate it, we can help with that, too.

16 thoughts on “General Instruments Video Game Chip Rides Again

  1. Are all of these chips dual-player or were there any variants where you can play against a “computer”? If not, it would be cool to implement a simple AI in a companion chip that would read the position of the ball, then set analog output to a certain value to position the paddle.

    1. The pong chips usually included a “practice” mode where the second player is replaced with a wall (and you score each time you hit it), but that’s it. Breakout games would allow single player where the goal is to clear the board, on the GI side there was the racing game where single player is just avoiding the obstacles while the battleship game had you fight a “computer” controlled player that moved in zigzag fashion (no real AI but still *some* challenge).

      To add AI to a pong chip you’d need to keep track of the sync pulses (for vsync) and the ball output pulse to tell where the ball is and react accordingly, and then simulate a potentiometer to feed it the vertical input. The real challenge would be to create a decent AI with era appropriate hardware.

      1. The potentiometer input feeds into a comparator and triggers the generation of the paddle from the scanline where it first flips the comparator output. Feed the ball output (all video components are separate outputs, to allow color with external circuitry) into the paddle input and the paddle will follow the ball and always hit it. No AI needed.

  2. I remember seeing a modification in a magazine that one could make (I did!) to a console to make the opposing paddle track the ball. If I remember correctly, there’s a pin that has the ball output on it, and one would use that along with another pin’s signal to charge and discharge a capacitor. The integrated voltage went to the paddle pot. This is well over 40 years ago, so the details are a bit fuzzy!

  3. “The Bildschirmspiel 01 (BSS 01) is the only game console that was developed and manufactured in the German Democratic Republic (GDR).
    It is based on the integrated circuit AY-3-8500 by General Instrument.
    The gameplay, controls and audiovisual presentation of the four individually selectable games are similar to Pong. ”

    ” Due to a lack of profitability, production was discontinued after just two years.
    A successor device with more game options and additional colored image output did not pass the prototype stage. ”


    I suppose it wasn’t really a” hit”, right?

    Some GDR citizens had homebrewed their own console, using the bare chip (AY-3-8500) as a basis.
    They used wooden chassis as a base, and old mouse traps as cobtrollers or something like that.

    Some pictures:

    Personally, I once got a TeleGames pong console (MBO/Palladium) at the flea market. Game play was so boring, so repetitive..

    No wonder people loved their Atari 2600, Interton VC4000 or Philips G7000/Odyssey 2.
    With such a initial situation..

    Taking that MBO pong console apart was much more fun than playing with it.
    In its defense, it looked cute.

    The console was just a passive chassis with some potentiometer-based paddles, a battery department and switches.

    The game logic itself was in the cartridge, so good games could have made for it.
    If it had lasted, I mean. The console didn’t make it. Understandable, given its content.

    I think that’s also true for this AY-something device here.
    Building your pong console is more thrilling than playing it afterwards.
    It’s a fine project for display in a museum.
    Using an acrylic chassis might be wise here.

  4. In the “squash” mode, with both paddles at one side, it was easy to get the two white bar paddles confused (especially if the other player was trying to make that happen!) I put a resistor in the luminance output of one paddle and turned it grey, making it easier to tell them apart.
    Like many of my early-teen projects, it was a wonder this worked instead of destroying the console!

  5. I have shelved the idea to make a modern PC-50X console with HDMI out, (the cartridges for the PC-50X series has AY-3-8500-1 descendants inside them) but I hope to have time in the future.

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