COSMAC VIP
Encyclopedia
The COSMAC VIP was an early microcomputer
that was aimed at video games. For a price of US$275, it could be purchased from RCA by mail order
. It came in kit form, and had to be assembled. Its dimensions were 22 x 28 cm, and it had a RCA 1802
processor; along with a crystal clock
operating at 1.76 MHz (3.521280 MHz divided by 2). It had 2 KB (2048 bytes) of RAM
, which could be expanded to 4 KB on board, and 32 KB via an expansion slot. Its 5V
DC
CDP18S023 power supply
had an output of 600 mA
. I/O
ports could be added to connect to sensors, interface relays, an ASCII
keyboard
, or a printer
.
The machine connected to either a video monitor or to a TV
with video input or by means of an external RF modulator. The VIP used a CDP1861/CDP1864 video display chip
to generate the video output, and sound could be played using its integrated speaker
. It had a 100 bytes per second cassette tape interface as well. Programs could be loaded into RAM from tapes, and vice versa. It also had a hex
keyboard for input, which had 16 keys spanning the hex digits 0 to F. LED
indicators were used to display power status and tape input; a third LED along with an on-board beeper were activated by the CPU's 1-bit "Q" register. A run/reset switch was used to start user programs
or the operating system
, respectively.
A simple 4-kilobit (512-byte) operating system was built into its ROM
. It allowed one to type in programs using its hex keyboard, show memory contents on its display
(step through the bytes of RAM), and view the values of the processor register
s. The ROM monitor was accessed by holding the "C" key while switching from Reset to Run. The COSMAC VIP was shipped with 20 video games, which were programmed in CHIP-8
. CHIP-8 was an early interpreted programming language
that was used on this machine and other early microcomputers, such as the Telmac 1800
. The video games that were provided came as a list of instructions which had to be typed in by the user.
The COSMAC VIP was created by the late Joseph Weisbecker of the RCA Laboratories in Princeton, New Jersey
.
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
that was aimed at video games. For a price of US$275, it could be purchased from RCA by mail order
Mail order
Mail order is a term which describes the buying of goods or services by mail delivery. The buyer places an order for the desired products with the merchant through some remote method such as through a telephone call or web site. Then, the products are delivered to the customer...
. It came in kit form, and had to be assembled. Its dimensions were 22 x 28 cm, and it had a RCA 1802
RCA 1802
The RCA CDP1802, also known as the COSMAC , is an 8-bit CMOS microprocessor introduced by RCA in early 1976. It is being by Intersil Corporation as a high-reliability microprocessor...
processor; along with a crystal clock
Clock signal
In electronics and especially synchronous digital circuits, a clock signal is a particular type of signal that oscillates between a high and a low state and is utilized like a metronome to coordinate actions of circuits...
operating at 1.76 MHz (3.521280 MHz divided by 2). It had 2 KB (2048 bytes) of RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...
, which could be expanded to 4 KB on board, and 32 KB via an expansion slot. Its 5V
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
DC
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
CDP18S023 power supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
had an output of 600 mA
Ampere
The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
. I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
ports could be added to connect to sensors, interface relays, an ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
keyboard
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
, or a printer
Computer printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...
.
The machine connected to either a video monitor or to a TV
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
with video input or by means of an external RF modulator. The VIP used a CDP1861/CDP1864 video display chip
Video Display Controller
A Video Display Controller or VDC is an integrated circuit which is the main component in a video signal generator, a device responsible for the production of a TV video signal in a computing or game system...
to generate the video output, and sound could be played using its integrated speaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...
. It had a 100 bytes per second cassette tape interface as well. Programs could be loaded into RAM from tapes, and vice versa. It also had a hex
Hexadecimal
In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
keyboard for input, which had 16 keys spanning the hex digits 0 to F. LED
Light-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
indicators were used to display power status and tape input; a third LED along with an on-board beeper were activated by the CPU's 1-bit "Q" register. A run/reset switch was used to start user programs
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
or the operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
, respectively.
A simple 4-kilobit (512-byte) operating system was built into its ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
. It allowed one to type in programs using its hex keyboard, show memory contents on its display
Display device
A display device is an output device for presentation of information in visual or tactile form...
(step through the bytes of RAM), and view the values of the processor register
Processor register
In computer architecture, a processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are addressed by mechanisms other than main memory and can be accessed more quickly...
s. The ROM monitor was accessed by holding the "C" key while switching from Reset to Run. The COSMAC VIP was shipped with 20 video games, which were programmed in CHIP-8
CHIP-8
CHIP-8 is an interpreted programming language, developed by the late Joseph Weisbecker. It was initially used on the COSMAC VIP and Telmac 1800 8-bit microcomputers in the mid-1970s. CHIP-8 programs are run on a CHIP-8 virtual machine...
. CHIP-8 was an early interpreted programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
that was used on this machine and other early microcomputers, such as the Telmac 1800
Telmac 1800
The Telmac 1800 was an early microcomputer delivered in kit form. It was introduced in 1977 by Telercas, the Finnish importer of RCA microchips. Most of the 2,000 kits manufactured were bought by electronics enthusiasts in Finland and Sweden....
. The video games that were provided came as a list of instructions which had to be typed in by the user.
The COSMAC VIP was created by the late Joseph Weisbecker of the RCA Laboratories in Princeton, New Jersey
Princeton, New Jersey
Princeton is a community located in Mercer County, New Jersey, United States. It is best known as the location of Princeton University, which has been sited in the community since 1756...
.
External links
- old-computers.com article: Cosmac VIP
- Recordings of Cosmac VIP playing music
- RCA COSMAC Yahoo! Group
- Chip8.com Website dedicated to Chip-8 and related systems. Maintains the most complete collection of Chip-8 programs on the net.
- Revival Studios Developer of new Chip-8/SuperChip/MegaChip8 games.
- Emma 02 including Cosmac VIP Emulator