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 — 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 -line NTSC version. It was introduced in 1976, Coleco becoming the first customer having been introduced to the IC development by Ralph H. Baer.[1] A minimum number of external components were needed to build a complete system.

AY-3-8500 chip

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:

Game Number of players
Tennis 2
Soccer 2
Squash 2
Practice 1
Rifle game 1 1
Rifle game 2 2

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[2]):

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:

Game Number of players
Tennis 2
Soccer 2
Squash 2
Practice 1
Rifle game 1 1
Rifle game 2 2

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.

AY-3-8610

AY-3-8610 chip from 1980

The AY-3-8610 was a major update from General Instruments. It played more games, 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.

Games

AY-3-8610 Hockey game
AY-3-8610 Tennis game
AY-3-8610 Gridball game
Hockey, tennis and gridball games on an AY-3-8610 based game cartridge

The 10 selectable games for this chip included:

Game Number of players
Tennis 2
Hockey 2
Soccer 2
Squash 2
Practice 1
Gridball 1
Basketball 2
Basketball practice 1
Two player target 2
Single player target 1

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.

The inside of an AY-3-8610 based game cartridge. The console for which this was made accepted other cartridges. However, unlike modern consoles, the game chip, i.e. the core circuitry, was in the cartridge, not in the console.

Derivatives

References

  1. ↑ http://www.pong-story.com/coleco.htm The Coleco Telstar story
  2. ↑ http://www.pong-story.com/mypongs.htm List of first era consoles

External links