Rahul Sharma

AY 3 8500

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AY-3-8500

The AY-3-8500 "Ball & Paddle" integrated circuit was the first in a series of ICs from General Instrument designed for the consumer video game market. These chips were designed to output video to an RF modulator, which would then display the game on a domestic television set. The AY-3-8500 contained six selectable games â€” tennis (a.k.a. Pong), soccer, squash, practice, and two rifle shooting games. The AY-3-8500 was the 625-line PAL version and the AY-3-8500-1 was the 525-line NTSC version. It was introduced in 1976, Coleco becoming the first customer having been introduced to the IC development by Ralph H. Baer. A minimum number of external components were needed to build a complete system.

Contents

The AY-3-8500 was the first version. It played seven Pong variations. The video was in black-and-white, although it was possible to colorize the game by using an additional chip, such as the AY-3-8515.

Games

Six selectable games for one or two players were included:

In addition, a seventh undocumented game could be played when none of the previous six was selected: Handicap, a soccer variant where the player on the right has a third paddle. This game was implemented on very few systems.

Usage

The AY-3-8500 was designed to be powered by six 1.5 V cells (9 V). Its specified operation is at 6...7 V and a maximum of 12 V instead of the 5 V standard for logic. The nominal clock was 2.0 MHz, yielding a 500 ns pixel width. One way to generate such a clock is to divide a 14.31818 MHz 4×colorburst clock by 7, producing 2.04545 MHz. It featured independent video outputs for left player, right player, ball, and playground+counter, that were summed using resistors, allowing designers to use a different luminance for each one. It was housed in a standard 28-pin DIP.

Applications

Some of the dedicated consoles employing the AY-3-8500 (there are at least two hundred different consoles using this chip):

  • Sears Hockey Pong
  • Coleco Telstar (Telstar, Classic, Deluxe, Ranger, Alpha, Colormatic, Regent, Sportsman)
  • Magnavox Odyssey series (300, 2000 and 3000)
  • Radio Shack TV ScoreBoard
  • Unisonic Sportsman/Tournament
  • Philips Tele-Spiel ES2203 and ES2204
  • Zanussi/Seleco Play-O-Tronic
  • Videomaster (Strika, Strika 2,ColourScore 2, SuperScore)
  • APF TV Fun (Model 401)
  • Sportsmaster TVG 901
  • AY-3-8550

    The AY-3-8550 was the next chip released by General Instruments. It featured horizontal player motion, and a composite video output. It was pin compatible with the AY-3-8500. It needed an additional AY-3-8515 chip to output video in color.

    Games

    Six selectable games for one or two players were included:

    Usage

    The AY-3-8550 used the No Connect pins from the AY-3-8500, so it was possible to put an AY-3-8550 on an AY-3-8500 (without horizontal movement), and vice versa.

    Application

    This is a list of consoles that use this chip:

  • Tele-Spiel ES 2208 Las Vegas
  • AY-3-8610

    The AY-3-8610 was a major update from General Instruments. It played more games (10), like basketball or hockey, with more graphics quality. It was nicknamed "Superstar" by GI. It was in black and white, although it's possible to add colour by using an additional AY-3-8615 chip.

    Before the 8610, had been produced the AY-3-8600. The pin configuration was the same of 8610 but it had ony 8 games; it didn't have the two rifle/target games.

    Games

    The 10 selectable games for this chip included:

    Usage

    The AY-3-8610 featured a completely different pinout. It, too, required an external crystal oscillator. It still has separate video output pins, and the dedicated sync pin is now gone.

    Application

    This is a list of consoles that use the AY-3-8610:

    Some consoles that use the AY-3-8600 chip:

    Derivatives

  • An equivalent to the AY-3-8500 is the TMS1965NLA manufactured by Texas Instruments.
  • The Soviet K145IK17 has built-in counter, making it possible to use momentary pushbutton instead of multi-position switch to select games. Handicap game is not hidden, it can be chosen among others using this button. Since pushbutton occupies only one pin, this IC has less pins.
  • A competitor was the National Semiconductor MM57105.
  • References

    AY-3-8500 Wikipedia


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