The 6532 RAM-I/O-Timer (RIOT) was an integrated circuit made by

MOS Technology MOS Technology, Inc. ("MOS" being short for Metal Oxide Semiconductor), later known as CSG (Commodore Semiconductor Group) and GMT Microelectronics, was a semiconductor design and fabrication company based in Audubon, Pennsylvania. It is mos ...

, as well as second sources such as Rockwell. It incorporated 128

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...

s of static RAM, two

bidirectional Bidirectional may refer to: * Bidirectional, a roadway that carries traffic moving in opposite directions * Bi-directional vehicle, a tram or train or any other vehicle that can be controlled from either end and can move forward or backward with e ...

8-bit digital

input/output In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...

ports, and a

Programmable interval timer In CPU, computing and in embedded systems, a programmable interval timer (PIT) is a Counter (digital), counter that generates an output signal when it reaches a programmed count. The output signal may trigger an interrupt. Common features PITs may ...

. This high degree of integration made it quite popular in the late 1970s and early 1980s, as it could take the place of several different integrated circuits (ICs). Perhaps its best-known application was the

Atari 2600 The Atari 2600, initially branded as the Atari Video Computer System (Atari VCS) from its release until November 1982, is a home video game console developed and produced by Atari, Inc. Released in September 1977, it popularized microprocesso ...

video game console A video game console is an electronic device that outputs a video signal or image to display a video game that can be played with a game controller. These may be home consoles, which are generally placed in a permanent location connected to ...

. The chip was also famously deployed in

Gottlieb Gottlieb (formerly D. Gottlieb & Co.) was an American arcade game corporation based in Chicago, Illinois. History The main office and plant was located at 1140-50 N. Kostner Avenue until the early 1970s when a new modern plant and office was lo ...

pinball machines, such as ''

Haunted House A haunted house, spook house or ghost house in ghostlore is a house or other building often perceived as being inhabited by disembodied spirits of the deceased who may have been former residents or were otherwise connected with the prope ...

'' and '' Black Hole'', the

Atari 810 The Atari 810 is the official floppy disk drive for the Atari 400 and 800, the first two models in the Atari 8-bit family of home computers. It was released by Atari, Inc. in 1980. The single-density drive provides 90 kB of storage. The 8 ...

and 1050 disk drives, as well as Commodore's 8050, 8250 & 8250LP

PET A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence ...

disk drives. The Atari 850 Interface, which gave Atari 400 and 800 computers an

RS-232 In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such ...

interface, used two 6532 chips. 6532 ICs were available in 1

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

and 2 MHz versions. The form factor was a

JEDEC The JEDEC Solid State Technology Association is an independent semiconductor engineering trade organization and standardization body headquartered in Arlington County, Virginia, United States. JEDEC has over 300 members, including some of the w ...

-standard, 40-pin DIP (ceramic or plastic).

External links

6532 Datasheet (MOS) (GIF format, zipped)6532 Datasheet (Rockwell) (PDF format)
{{Compu-hardware-stub MOS Technology integrated circuits