BESYS (Bell Operating System) was an early computing environment originally implemented as a

batch processing 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 ...

operating system in 1957 at

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

for the

IBM 704 The IBM 704 is a large digital mainframe computer introduced by IBM in 1954. It was the first mass-produced computer with hardware for floating-point arithmetic. The IBM 704 ''Manual of operation'' states: The type 704 Electronic Data-Pro ...

computer.

Overview

The system was developed because Bell recognized a "definite mismatch…between the 704's internal speed, the sluggishness of its on-line unit-record equipment, and the inherent slowness of manual operations associated with stand-alone use." According to Drummond, the name BESYS, though commonly thought to stand for BEll SYStem, is actually a concatenation of the preexisting SHARE-assigned installation code BE for Bell Telephone Laboratories, Murray Hill, NJ and the code assigned by SHARE for systems software, SYS. The goals of the system were: * Flexible use of hardware, nonstop operation. * Efficient batch processing, tape-to-tape operation with offline spooling of unit-record data. * Use of control cards to minimize the need for operator intervention. * Allow user programs access to

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 ...

functions, system control and

program libraries In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subr ...

. *

Core dump In computing, a core dump, memory dump, crash dump, storage dump, system dump, or ABEND dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has crashed or otherwise terminat ...

facilities for

debugging In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve in ...

. * Simulation of L1 and L2 interpreters to provide software compatibility with the

IBM 650 The IBM 650 Magnetic Drum Data-Processing Machine is an early digital computer produced by IBM in the mid-1950s. It was the first mass produced computer in the world. Almost 2,000 systems were produced, the last in 1962, and it was the first ...

. The initial version of the system BESYS-1 was in use by October 16, 1957. It was created by George H. Mealy and Gwen Hansen with Wanda Lee Mammel and utilized IBM's FORTRAN and

United Aircraft The United Aircraft Corporation was an American aircraft manufacturer formed by the break-up of United Aircraft and Transport Corporation in 1934. In 1975, the company became United Technologies. History Pre-1930s 1930s The Air Mail scandal ...

Symbolic Assembly Program The Symbolic Assembly Program (SAP) is an assembler program for the IBM 704 computer. It was written by Roy Nutt at United Aircraft Corporation, and was distributed by the SHARE user's group beginning in 1956 as the ''Share Assembly Program''. S ...

(SAP) programming languages. It was designed to efficiently deal with a large number of jobs originating on

punched card A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to di ...

s and producing results suitable for printing on paper and punched cards. The system also provided processing capabilities for data stored on

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 magne ...

s and

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 ...

storage units. Typically punched card and print processing was handled off line by peripheral Electronic Accounting Machines,

IBM 1401 The IBM 1401 is a variable-wordlength decimal computer that was announced by IBM on October 5, 1959. The first member of the highly successful IBM 1400 series, it was aimed at replacing unit record equipment for processing data stored on pu ...

computers, and eventually direct coupled computers. The first system actually used at Bell Labs was BESYS-2. The system was resident on

, and occupied the lowest 64 (36-bit) words and the highest 4K words of memory. The upper 4K words held the resident portion of the monitor, and could be partially swapped to

magnetic drum Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. For many early computers, drum memory formed the main working memory ...

to free up additional core for the user program if needed. "BESYS was a complex software package that provided convenient input/output and integrated disk file storage facilities."

Internal use

BESYS was used extensively by many departments of Bell Labs for over a decade. It was made available through the SHARE organization to others without charge or formal technical support.

BESYS versions

Versions of the BESYS environment (BESYS-3 (1960), BESYS-4 (1962), BESYS-5 (1963), BESYS-7 (1964), and BE90 (1968)) were implemented as the underlying computers transitioned through the IBM 709X family. BESYS development was discontinued when Bell Labs moved to the

IBM System/360 The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover both commercial and scientific applica ...

in 1969. Throughout this period the head of the BESYS development project was George L. Baldwin.

References

1957 software Bell Labs Discontinued operating systems {{operating-system-stub