The CDC 1604 was a 48-bit computer designed and manufactured by
Seymour Cray
Seymour Roger Cray (September 28, 1925 – October 5, 1996 ) was an American
Control Data Corporation
Control Data Corporation (CDC) was a mainframe and supercomputer firm. CDC was one of the nine major United States computer companies through most of the 1960s; the others were IBM, Burroughs Corporation, DEC, NCR, General Electric, Honeywe ...
(CDC). The 1604 is known as one of the first commercially successful
transistorized computers
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch e ...
. (The
IBM 7090
The IBM 7090 is a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computer that was designed for "large-scale scientific and technological applications". The 7090 is the fourth member of the IBM 700/7000 se ...
was delivered earlier, in November 1959.) Legend has it that the 1604 designation was chosen by adding CDC's first street address (501 Park Avenue) to Cray's former project, the ERA-
UNIVAC 1103
The UNIVAC 1103 or ERA 1103, a successor to the UNIVAC 1101, was a computer system designed by Engineering Research Associates and built by the Remington Rand corporation in October 1953. It was the first computer for which Seymour Cray was cred ...
.
A cut-down 24-bit version, designated the CDC 924, was shortly thereafter produced, and delivered to NASA.
The first 1604 was delivered to the
U.S. Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...
Post Graduate School in January 1960 for applications supporting major
Fleet Operations Control Center
Fleet may refer to:
Vehicles
*Fishing fleet
*Naval fleet
*Fleet vehicles, a pool of motor vehicles
*Fleet Aircraft, the aircraft manufacturing company
Places
Canada
* Fleet, Alberta, Canada, a hamlet
England
* The Fleet Lagoon, at Chesil Beach ...
s primarily for weather prediction in
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
,
London
London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
, and
Norfolk, Virginia
Norfolk ( ) is an independent city in the Commonwealth of Virginia in the United States. Incorporated in 1705, it had a population of 238,005 at the 2020 census, making it the third-most populous city in Virginia after neighboring Virginia B ...
. By 1964, over 50 systems were built. The
CDC 3600
The CDC 3000 series ("thirty-six hundred" of "thirty-one hundred") computers from Control Data Corporation were mid-1960s follow-ons to the CDC 1604 and CDC 924 systems.
Over time, a range of machines were produced - divided into
* the 48-bit up ...
, which added five op codes, succeeded the 1604, and "was largely compatible" with it.
One of the 1604s was shipped to the Pentagon to DASA (Defense Atomic Support Agency) and used during the Cuban missile crises to predict possible strikes by the Soviet Union against the United States.
A 12-bit
minicomputer
A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ' ...
, called the
CDC 160
The CDC 160 series was a series of minicomputers built by Control Data Corporation. The CDC 160 and CDC 160-A were 12-bit minicomputers built from 1960 to 1965; the CDC 160G was a 13-bit minicomputer, with an extended version of the CDC 160-A ins ...
, was often used as an I/O processor in 1604 systems. A stand-alone version of the 160 called the CDC 160-A was arguably the first minicomputer.
words
A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no conse ...
of magnetic
core memory
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (manufacturing), used in casting and molding
* Core (optical fiber), the signal-carrying portion of an optical fiber
* Core, the centra ...
with a cycle time of 6.4 microseconds. It was organized as two banks of 16K words each, with odd addresses in one bank and even addresses in the other. The two banks were phased 3.2 microseconds apart, so average effective memory access time was 4.8 microseconds. The computer executed about 100,000 operations per second.
Each 48-bit word contained two 24-bit instructions. The instruction format was 6-3-15: six bits for the operation code, three bits for a "designator" (index register for memory access instructions, condition for jump (branch) instructions) and fifteen bits for a memory address (or shift count, for shift instructions).
The CPU contained a 48-bit accumulator (A), a 48-bit Auxiliary Arithmetic register (Q), a 15-bit program counter (P), and six 15-bit index registers (1-6). The Q register was usually used in conjunction with A for forming a double-length register AQ or QA, participating with A in multiplication, division and logical product (masking) operations, and temporary storage of A's contents while using A for another operation.
Internal integer representation used
ones' complement
The ones' complement of a binary number is the value obtained by inverting all the bits in the binary representation of the number (swapping 0s and 1s). The name "ones' complement" (''note this is possessive of the plural "ones", not of a sin ...
arithmetic. Internal floating point format was 1-11-36: one bit of sign, eleven bits of offset (biased) binary exponent, and thirty-six bits of binary significand.
The most-significant three bits of the accumulator were converted from digital to analog and connected to a tube audio amplifier contained in the console. This facility could be used to program audio alerts for the computer operator, or to generate music. Those familiar with the inner workings of the software could often hear what parts of a task were being performed by the CDC 1604; as a debugging aid, for example, a never-ending repetitive musical phrase indicated the program was stuck in a loop.
Uses and applications
In 1960, one of the first text-mining applications, ''Masquerade'', was written for the
Marathon Oil
Marathon Oil Corporation is an American company engaged in hydrocarbon exploration incorporated in Ohio and headquartered in the Marathon Oil Tower in Houston, Texas. A direct descendant of Standard Oil, it also runs international gas operations ...
Company in
Findlay, Ohio
Findlay ( ) is a city in and the county seat of Hancock County, Ohio, United States. The second-largest city in Northwest Ohio, Findlay lies about 40 miles (64 km) south of Toledo. The population was 40,313 at the 2020 census. It is home ...
. Masquerade was a
text-mining
Text mining, also referred to as ''text data mining'', similar to text analytics, is the process of deriving high-quality information from text. It involves "the discovery by computer of new, previously unknown information, by automatically extract ...
program that used syntactic structures underlying text data to mask out words and phrases for searching purposes.
During 1969, Fleet Operations Control Center, Pacific ( FOCCPAC at Kunia) on
Oahu
Oahu () ( Hawaiian: ''Oʻahu'' ()), also known as "The Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over two-thirds of the population of the U.S. state of Hawaii. The island of O ...
in
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
launched an ''Automated Control Environment'' (ACE) using a cluster of five CDC 160As to supervise a multi-tasking network of four CDC 1604s.
The Minuteman I was the first U.S. solid-rocket ICBM system to be fielded. There were two entirely separate ground station designs which were developed independently. The smaller, more elegant, single silo design incorporated two redundant CDC 1604 computer systems, each equipped with dual cabinets containing four 200 bpi
magnetic tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnet ...
drives. The computers were used to pre-compute guidance and aiming control information. Results based on current weather and targeting information were downloaded into the missile prior to launch. Model displays of both of these ICBM ground station designs, including block models of the CDC 1604 computers, may be viewed at the
Octave Chanute Aerospace Museum
The Octave Chanute Aerospace Museum, the largest aviation museum in Illinois, occupied part of the grounds of the decommissioned Chanute Air Force Base in Rantoul, Illinois. It and the base were named for Octave Chanute, railroad engineer and avi ...
in Rantoul, Illinois.
The third version of the
PLATO
Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...
computer-based educational system was implemented on a CDC 1604-C.
JOVIAL
JOVIAL is a high-level programming language based on ALGOL 58, specialized for developing embedded systems (specialized computer systems designed to perform one or a few dedicated functions, usually embedded as part of a larger, more complete dev ...
was used as the main programming language of the CDC 1604, while
octal
The octal numeral system, or oct for short, is the radix, base-8 number system, and uses the Numerical digit, digits 0 to 7. This is to say that 10octal represents eight and 100octal represents sixty-four. However, English, like most languages, ...
was used to program shared services supported by the CDC 160A. NAVCOSSACT based at the
Washington Navy Yard
The Washington Navy Yard (WNY) is the former shipyard and ordnance plant of the United States Navy in Southeast Washington, D.C. It is the oldest shore establishment of the U.S. Navy.
The Yard currently serves as a ceremonial and administrat ...
provided systems and training support.
The CDC 1604 was used to compose Sailboat and other artworks by Sam Schmitt and Stockton Gaines.
Similar machines
The 1604 design was used by the Soviet nuclear weapons laboratory. Their
BESM-6
BESM-6 (russian: БЭСМ-6, short for ''Большая электронно-счётная машина'', i.e. 'Large Electronic Calculating Machine') was a Soviet electronic computer of the BESM series. It was the first Soviet second-generation ...
computer, which entered production in 1968, was designed to be somewhat software compatible with the CDC 1604, but it ran 10 times faster and had additional registers.
The 924
The CDC 924 was a 24-bit computer that supported the use of "any input-output devices capable of communicating with the 160 and/or 1604 computer," and its six independent channels permitted 3 simultaneous input operations even as 3 channels concurrently performed output.
Like many CDC processors, it used ones' complement arithmetic.
Some advanced features of the 924, which included 64 instructions, were:
* Six index registers. The value "7" was reserved to indicate indirect-addressing.
* an execute instruction (in what the hardware reference manual called "a subroutine of a single instruction").
* powerful Storage Search instructions.
Charles Babbage Institute
The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...
, University of Minnesota. Engineers include Robert Moe, Wayne Specker, Dennis Grinna, Tom Rowan, Maurice Hutson, Curt Alexander, Don Pagelkopf, Maris Bergmanis, Dolan Toth, Chuck Hawley, Larry Krueger, Mike Pavlov, Dave Resnick, Howard Krohn, Bill Bhend, Kent Steiner, Raymon Kort, and Neil R. Lincoln. Discussion topics include CDC 1604,
CDC 6600
The CDC 6600 was the flagship of the 6000 series of mainframe computer systems manufactured by Control Data Corporation. Generally considered to be the first successful supercomputer, it outperformed the industry's prior recordholder, the IBM ...
,
CDC 7600
The CDC 7600 was the Seymour Cray-designed successor to the CDC 6600, extending Control Data's dominance of the supercomputer field into the 1970s. The 7600 ran at 36.4 MHz (27.5 ns clock cycle) and had a 65 Kword primary memory (with a 6 ...
,
CDC 8600
The CDC 8600 was the last of Seymour Cray's supercomputer designs while he worked for Control Data Corporation. As the natural successor to the CDC 6600 and CDC 7600, the 8600 was intended to be about 10 times as fast as the 7600, already the f ...
1604
Events
January–June
* January 1 – ''The Masque of Indian and China Knights'' is performed by courtiers of James VI and I at Hampton Court.
* January 14 – The Hampton Court Conference is held between James I of England, ...
