The
CDC 3000 series computers from
Control Data CorporationControl Data Corporation was a supercomputer firm. For most of the 1960s, it built the fastest computers in the world by far, only losing that crown in the 1970s after Seymour Cray left the company to found Cray Research, Inc....
were mid-1960s follow-ons to the
CDC 1604The CDC 1604 was a 48-bit computer designed and manufactured by Seymour Cray and his team at the Control Data Corporation. The 1604 is known as the first commercially successful transistorized computer. Legend has it that the 1604 designation was chosen by adding CDC's first street address to...
and CDC 924 systems. Over time, a range of machines were produced - divided into the 'upper 3000 series' and the 'lower 3000 series'. CDC phased out production of the 3000 series in the early 1970s. The 3000 series were the 'cash cows' of Control Data during the 1960s; sales of these machines funded the company while the
6000 seriesThe CDC 6000 series was a family of mainframe computers manufactured by Control Data Corporation in the 1960s. It consisted of CDC 6400, CDC 6500, CDC 6600 and CDC 6700 computers, which all were extremely rapid and efficient for their time...
was designed.
The upper 3000 series used a 48 bit word size. The first machine to be produced was the
CDC 3600; first delivered in June 1963. First deliveries of the
CDC 3400 and
CDC 3800 were in December 1965. These machines were designed for scientific computing applications, however were eventually overshadowed by the 60-bit
CDC 6000 seriesThe CDC 6000 series was a family of mainframe computers manufactured by Control Data Corporation in the 1960s. It consisted of CDC 6400, CDC 6500, CDC 6600 and CDC 6700 computers, which all were extremely rapid and efficient for their time...
machines.
The lower 3000 series used a 24 bit word size. They were based on the earlier CDC 924 - a 24-bit version of the
CDC 1604The CDC 1604 was a 48-bit computer designed and manufactured by Seymour Cray and his team at the Control Data Corporation. The 1604 is known as the first commercially successful transistorized computer. Legend has it that the 1604 designation was chosen by adding CDC's first street address to...
. The first lower 3000 to be released was the
CDC 3200 (May 1964), followed by the smaller
CDC 3100 (February 1965), and the
CDC 3300 (December 1965). The final machine in the series, the
CDC 3500, was released in march of 1967 and used
integrated circuitAn integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s instead of discrete components. The 3300 and 3500 had optional relocation capabilities, floating point, and
BDP (Business + Data Processing) instructions. These machines were targeted towards 'business and commercial' computing.
The instruction set of the upper 3000 series was composed mostly of 24-bit instructions (packed 2 per word), but also contained some 48-bit instructions. The lower 3000 was based on a 24-bit subset of those available on the upper 3000 systems. It was therefore possible to write programs which would run on all 3000 systems. And as these systems were based on the prior 1604 and 924 instruction sets, some
backward compatibilityIn the context of telecommunications and computing, a device or technology is said to be backward or downward compatible if it can work with input generated by an older device...
also existed. However the systems did diverge from each other in areas such as relocation and the BDP instructions.
Almost all 3000 series computers used core memory. However, the CDC 3500 machine used an integrated circuit memory.
Architecture
The lower 3000 CPU was a 24-bit architecture: instructions were 24 bits in length, as were the two operand registers A and Q. There were 4 index registers of 15 bits, B0 through B3, though B0 is always zero (zero when read; writes don't affect the value). There was no status (flags or condition code) register. Up to 32,768 (24-bit) words of core memory could be directly addressed, and multiple banks could be switched in. Two or three memory bank configurations were the most common.
Each instruction contained 6 bits of opcode, 1 bit specifying whether indirect addressing used, 2 bits of index register address and 15 bits of address.
Arithmetic was ones' complement, so there were two forms of zero: positive zero and negative zero. The A and Q register could function as a combined 48-bit register for certain arithmetic instructions. The E register had 48 bits.
The 3300 CPU could execute around 1 million instructions per second (1
MIPInstructions per second is a measure of a computer's processor speed. Many reported IPS values have represented "peak" execution rates on artificial instruction sequences with few branches, whereas realistic workloads typically lead to significantly lower IPS values...
), giving it supercomputer status in 1965.
Software
The earliest operating system for the lower 3000 series was called RTS OS. However it was quickly replaced with MSOS (Mass Storage OS). The premier
operating systemAn 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...
for the CDC 3300 and CDC 3500 was called MASTER. MASTER was interrupt-driven, supported large memory, multi-tasking.
An operating system called REAL-TIME
SCOPESCOPE, an acronym for Supervisory Control Of Program Execution, was the name used by the Control Data Corporation for a number of operating system projects in the 1960s.-Variants:* SCOPE for the CDC 3000 series....
existed for both lower- and upper-3000 systems. A disk-based version of SCOPE was eventually made available for the upper-3000 systems.
FORTRANFortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
,
COBOLCOBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
, and
ALGOLALGOL is a family of imperative computer programming languages originally developed in the mid 1950s which greatly influenced many other languages and became the de facto way algorithms were described in textbooks and academic works for almost the next 30 years...
were available. The
assembly languageAn assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
was called
COMPASSCOMPASS is an acronym for COMPrehensive ASSembler. COMPASS is any of a family of macro assembly languages on Control Data Corporation's 3000 series, and on the 60-bit CDC 6000 series, 7600 and Cyber 70 and 170 series mainframe computers...
. These were available from CDC.
An APL system for the upper 3000 series computers was developed at the
University of MassachusettsThis article relates to the statewide university system. For the flagship campus often referred to as "UMass", see University of Massachusetts Amherst...
. This system was made available to other users of the upper 3000 series.
Character set
The operating systems for the CDC 3xxx typically used 6 bit characters, so the
64 character set did not contain lowercase letters. The character set contained (in
display codeDisplay code is the 6-bit character set used by many computer systems manufactured by Control Data Corporation, notably the CDC 6600 in 1964. The CDC 6000 series, and their followons, had 60 bit words. As such, typical usage packed 10 characters per word....
order). This 6-bit extension of the 4-bit BCD encoding was referred to as BCDIC (BCD interchange code.) IBM later extended this code further to create the 8-bit "extended BCDIC", or
EBCDICExtended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
code.
: A-Z 0-9 + - * / $ =
(space) , . # [ ] % " _ ! & ' ? < > @ \ ^ ;
Depending on the device, some characters are rendered differently, especially the lineprinter and some terminals:
| character |
sometimes
displays as |
| # |
≡ |
| " |
≠ |
| _ |
→ or { |
| ! |
∨ |
| & |
∧ |
| ' |
↑ |
| ? |
↓ or } |
| @ |
≤ |
| \ |
≥ |
| ^ |
¬ |
Note the absence of control characters, especially
carriage returnCarriage return, often shortened to return, refers to a control character or mechanism used to start a new line of text.Originally, the term "carriage return" referred to a mechanism or lever on a typewriter...
and line feed. These were encoded by the record structure.
Partial list of users
Oregon State UniversityOregon State University is a coeducational, public research university located in Corvallis, Oregon, United States. The university offers undergraduate, graduate and doctoral degrees and a multitude of research opportunities. There are more than 200 academic degree programs offered through the...
offered a CDC 3300 for use from the mid to late 1960s up until about 1980. It used a home grown operating system known as OS3 (for Oregon State Open Shop Operating System).
The U.S.
Internal Revenue ServiceThe Internal Revenue Service is the revenue service of the United States federal government. The agency is a bureau of the Department of the Treasury, and is under the immediate direction of the Commissioner of Internal Revenue...
used CDC 3000 series computers for many years.
A number of CDC 3000s were installed in France, either in academic computing centers, in software companies or in the aeronautics, nuclear and oil industries.
Communist-ruled Hungary obtained a CDC 3300 machine between 1969 and 1971. It was administered by the National Academy of Sciences throughout the 1970s, mainly for running scientific computations.
International Timesharing Corporation sold timesharing services using a CDC 3600.
California State University at Northridge had a dual 3170 that provided timesharing service to the California State University and College system. Many of the other campuses also had CDC 3150 machines for local batch operation.
The US Force used numerous CDC 3800 series systems in the AFSCF
Air Force Satellite Control FacilityThe United States Air Force's Air Force Satellite Control Facility was a space command and control unit located at Onizuka AFB, California. It has the distinction of being heavily involved in the world's first reconnaissance satellite program, CORONA. Due to geological hazards The United States...
located at what is now
Onizuka Air Force StationOnizuka Air Force Station was a United States Air Force installation in Santa Clara County, California, just outside the city limits of Sunnyvale, at the intersection of U.S. Route 101 and State Route 237...
in Sunnyvale CA. As part of the
Air Force Satellite Control NetworkThe Air Force Satellite Control Network provides support for the operation, control, and maintenance of a variety of United States Department of Defense and some non-DoD satellites. This involves continual execution of the tasks involved in Tracking, Telemetry, and Command...
they were used to do orbital planning and maintenance calculations for DOD satellites until they were phased out and replaced by IBM mainframes in the mid 1980s. These systems used the
JOVIALJOVIAL is a high-order computer programming language similar to ALGOL, but specialized for the development of embedded systems .JOVIAL is an acronym for "Jules Own Version of the International...
programming language to provide the accuracy necessary for these calculations.
Other CDC 3300 systems installed in former Eastern Bloc Countries (list not complete):
- Computing Research Centre, Bratislava
- Central Statistical Office, Prague.
- Romanian Aircraft, Bucharest (3500 System)
External references