The CDC 1700 is a 16-bit word

minicomputer A minicomputer, or colloquially mini, is a type of general-purpose computer mostly developed from the mid-1960s, built significantly smaller and sold at a much lower price than mainframe computers . By 21st century-standards however, a mini is ...

, manufactured by the

Control Data Corporation Control Data Corporation (CDC) was a mainframe and supercomputer company that in the 1960s was one of the nine major U.S. computer companies, which group included IBM, the Burroughs Corporation, and the Digital Equipment Corporation (DEC), the N ...

with deliveries beginning in May 1966. Over the years there were several versions. The original 1700 was constructed using air-cooled

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 I ...

-like cordwood logic modules and

core memory Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (laboratory), a highly specialized shared research resource * Core (manufacturing), used in casting and molding * Core (optical fiber), ...

, although later models used different technology. The final models, called Cyber-18, added four general-purpose registers and a number of instructions to support a

time-sharing In computing, time-sharing is the Concurrency (computer science), concurrent sharing of a computing resource among many tasks or users by giving each Process (computing), task or User (computing), user a small slice of CPU time, processing time. ...

operating system.

Hardware

The 1700 uses

ones' complement The ones' complement of a binary number is the value obtained by inverting (flipping) all the bits in the Binary number, binary representation of the number. The name "ones' complement" refers to the fact that such an inverted value, if added t ...

arithmetic and an

ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...

-based

character set Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using computers. The numerical values that make up a c ...

, and supports memory write protection on an individual word basis. It has one general-purpose

register Register or registration may refer to: Arts, entertainment, and media Music * Register (music), the relative "height" or range of a note, melody, part, instrument, etc. * ''Register'', a 2017 album by Travis Miller * Registration (organ), ...

and two indexing registers (one of which was implemented as a dedicated memory location). The

instruction set In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, s ...

is fairly simple and supports seven storage

addressing mode Addressing modes are an aspect of the instruction set architecture in most central processing unit (CPU) designs. The various addressing modes that are defined in a given instruction set architecture define how the machine language instructions ...

s, including multilevel (chained) indirect addressing. Although described as a 16-bit system, the basic core storage memory is 4,096 18-bit words, each comprising * 16 data bits * a parity bit, and * a program protection bit;
memory could be expanded to 32,768 words; I/O was in units of 8 or 16 bits.

Peripherals

Available peripherals included teletypewriters,

paper tape Five- and eight-hole wide punched paper tape Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop Punched tape or perforated paper tape is a form of data st ...

readers/punches,

punched card A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...

readers/punches,

line printer A line printer Printer (computing), prints one entire line of text before advancing to another line. Most early line printers were printer (computing)#Impact printers, impact printers. Line printers are mostly associated with unit record eq ...

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 magnetic ...

drives, magnetic drums, fixed and removable

magnetic disk Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetizable material to store data and is a form of non-volatile memory. The information is ac ...

drives, display terminals, communications controllers, Digigraphic display units, timers, etc. These interfaced to the processor using unbuffered

interrupt In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted ...

-driven "A/Q" channels or buffered Direct Storage Access channels.

Software

The main operating systems for the 1700 were the Utility System, which usually took the form of several punched paper tapes (

resident monitor In computing, a resident monitor is a type of system software program that was used in many early computers from the 1950s to 1970s. It can be considered a precursor to the operating system. The name is derived from a program which is always pre ...

plus utilities), a similar Operating System for larger configurations (often including

punched cards A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were wide ...

and

), and the Mass Storage Operating System (MSOS) for disk-based systems. An assembler and a Fortran compiler were available. Pascal was also available, via a

cross compiler A cross compiler is a compiler capable of creating executable code for a platform other than the one on which the compiler is running. For example, a compiler that runs on a PC but generates code that runs on Android devices is a cross compile ...

on a

CDC 6000 series The CDC 6000 series is a discontinued family of mainframe computers manufactured by Control Data Corporation in the 1960s. It consisted of the CDC 6200, CDC 6300, #Versions, CDC 6400, #Versions, CDC 6500, CDC 6600 and #Versions, CDC 6700 computers, ...

host. The Cyber 18 series, exploiting the extended instruction set, ran a disk-based OS, the Interactive Terminal Oriented System (ITOS). This system supported Fortran, Cobol, and

UCSD Pascal UCSD Pascal is a Pascal programming language system that runs on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1977. It was developed at the University of California, San Diego (UC ...

. ITOS was a foreground/background system with multiple users connected via serial

CRT CRT or Crt most commonly refers to: * Cathode-ray tube, a display * Critical race theory, an academic framework of analysis CRT may also refer to: Law * Charitable remainder trust, United States * Civil Resolution Tribunal, Canada * Columbia ...

terminals; user tasks ran in the background while the operating system itself ran in the foreground.

Market acceptance

The 1700 series found use as communications concentrators,

Digigraphics Digigraphics was one of the first graphical computer aided design systems to go on sale. Originally developed at Itek on the PDP-1 as EDM (''Electronic Drafting Machine''), the efforts were purchased by Control Data Corporation and ported to their m ...

workstation A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...

s, remote

batch job Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically ...

entry stations, and industrial

process control Industrial process control (IPC) or simply process control is a system used in modern manufacturing which uses the principles of control theory and physical industrial control systems to monitor, control and optimize continuous Industrial processe ...

lers. One application, running the AUTRAN program, controlled water and wastewater treatment plants for many years. Another was used as Maintenance and Diagnostic SubSystem (M&DSS) for the AN/FPQ-16 Perimeter Acquisition Radar Attack Characterization System (PARCS), located at Cavalier Air Force Station (CAFS) in North Dakota; this CDC 1700 is still being used as of this writing (2016).

Washington, D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...

used a Control Data 1700 in vote-tallying. CDC's 1700 was also used by Ticketron as central servers for their wagering systems and ticketing services.

Simulation

In mid-2016, John Forecast added a CDC 1700 simulator to the

SIMH SIMH is a free and open source, multi-platform multi-system emulator. It is maintained by Bob Supnik, a former DEC engineer and DEC vice president, and has been in development in one form or another since the 1960s. History SIMH was based o ...

package.

Photos

CDC 1700 Control Panel

Control Data 1700

References

Philips Technical Review, Volume 36, 1976, No., p.162 ff. Computer-aided design by Peter Blume: An early application of the CDC 1700 Digigraphic: shows in Fig. 4 a complete schematic of the computer configuration and in Fig. 5 a picture of the Digigraphic display Abstract:.... Work has been in progress at the Philips Laboratories in Hamburg since 1973 ... on an integrated computer system in which parts are completely detailed in a dialogue between the designer and a computer via an "interactive display" ... The mentioned display is the display of the CDC 1700 Digigraphic. Fig. 4 Figure caption: The CDC 1700 Digigraphic computer system for the graphic processing of data. The interactive display is connected to the CD 1704 central processor via a control unit with a "picture store"; the computer itself has the usual mass stores and peripheral equipment. Information from the computer store can be displayed on the screen of the picture tube and can be altered or added to by using a light pen and keyboards connected to the interactive display. This means that very fast input of both alphanumeric and graphic information is possible, while the input can be verified immediately on the screen.

External links

CDC 1700 Reference Manual (September 1965)
{{Control Data Corporation

1700 As of March 1 ( O.S. February 19), where the Julian calendar acknowledged a leap day and the Gregorian calendar did not, the Julian calendar fell one day further behind, bringing the difference to 11 days until February 28 ( O.S. February 17) ...

Minicomputers 16-bit computers