The AY-3-8500 "Ball & Paddle" integrated circuit (IC, or "chip") was the first in a series of ICs from General Instrument designed for the consumer video game market. These chips output video to an RF modulator, which would then display the game on a domestic television set. It was introduced in 1976, Coleco becoming the first customer, having been introduced to the IC development by Ralph H. Baer.[1] The lineup was later known as the GIMINI series. Approximately 5 million 8500s were sold and used in hundreds of different consoles.[2]
The 8500 contained six selectable games — tennis (a.k.a. Pong), hockey (or soccer), squash, practice (single-player Pong), and two shooting games. The 8500 was the 625-line PAL version and the 8500-1 was the 525-line NTSC version. A minimum number of external components were needed to build a complete system. The video was in black-and-white, although it was possible to colorize the game by using an additional chip, the AY-3-8515.
The 8500 was later updated with the AY-3-8550, which used formerly unused pins on the 8500 to add two-axis control with a joystick instead of the more typical single-axis (up and down) control with a paddle. It was otherwise similar and played the same games, and could also be used with the 8515 for color support. The AY-3-8610, also known as the "Superstar", added several new games and required the new AY-3-8615 for color support.
The 8500 development was led by GI's Stephen Maine, working with Eric Berman and Duncan Harrower. Harrower had begun working on the concept in 1974. The system was announced in December 1975 and began shipping early the next year. Coleco was the first customer, with Radio Shack and Magnavox following. Ultimately it was used by "hundreds of different games systems" around the world, and over 5 million were sold in 1976 alone.[2]
The company continued development of the 8500 series, introducing new dedicated games chips. However, as they noted, "dedicated television game chips consumed huge resources to develop",[2] a problem also noted by competitor Atari at the same time. Both companies began developing new second-generation systems, using a general purpose central processing unit (CPU) to handle logic, and a dedicated video display unit (VDU) to produce the graphics.[2]
AY-3-8500
Games
Game
No. of players
Practice
1
Shooting game 1
Shooting game 2
2
Tennis
Hockey/Soccer
Squash
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 hockey variant where the player on the right has a third paddle. This game was implemented on very few systems.
Usage
AY-3-8500
The AY-3-8500 was designed to be powered by six 1.5V cells (9V). Its specified operation is at 6-7V and a maximum of 12V instead of the 5V standard for logic. The nominal clock was 2.0MHz, yielding a 500ns pixel width. One way to generate such a clock is to divide a 14.31818MHz 4×colorburst clock by 7, producing 2.04545MHz. 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. The image could be colorized using the AY-3-8515 chip, which converted luminance values to pre-selected colors.
Applications
Some of the dedicated consoles employing the AY-3-8500 (there are at least two hundred different consoles using this chip[3]):
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
Game
No. of players
Practice
1
Shooting game 1
Shooting game 2
2
Tennis
Hockey/Soccer
Squash
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.
The AY-3-8610 was a major update from General Instruments. It played more games (10),[5] like basketball or hockey, with higher-quality graphics. It was nicknamed "Superstar" by GI. It was in black and white, although it was possible to add color by using an additional AY-3-8615 chip.
Prior to producing the 8610, GI created the AY-3-8600. The pin configuration was the same as the 8610, but it was missing the two rifle/target games, bringing the total number of games down to 8.
Games
Hockey, tennis and gridball on an AY-3-8610 based game cartridge
The 10 selectable games for this chip included:
Game
No. of players
Tennis
2
Hockey/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 had separate video output pins, and removed the dedicated sync pin.
AY-3-8610The 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.
Application
This is a list of consoles that use the AY-3-8610:[3]
The Soviet K145IK17 (Russian: К145ИК17) has a built-in counter, making it possible to use a momentary pushbutton instead of a multi-position switch to select games. The handicap game is not hidden, it can be chosen among others using this button. Since a pushbutton occupies only one pin, this IC has fewer pins.
12"Archived copy"(PDF). Archived from the original(PDF) on 2012-03-16. Retrieved 2012-11-17.{{cite web}}: CS1 maint: archived copy as title (link) Gimini - TV Game Circuits
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