The
IBM 700/7000 series was a series of large-scale (
mainframeMainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
) computer systems made by IBM through the 1950s and early 1960s. The series included several different, incompatible processor architectures. The 700s used
vacuum tubeIn electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
logic and were made obsolete by the introduction of the
transistorizedA transistor computer is a computer which uses discrete transistors instead of vacuum tubes. The "first generation" of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky, and were unreliable. A "second generation" of computers, through the late 1950s and...
7000s. The 7000s, in turn, were eventually replaced by
System/360The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
, which was announced in 1964. However the 360/65, the first 360 powerful enough to replace 7000s, did not become available until November 1965. Early problems with OS/360 and the high cost of converting software kept many 7000s in service for years afterward.
Architectures
The IBM 700/7000 series had six completely different ways of storing data and instructions:
- First (36/18-bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
words): 701The IBM 701, known as the Defense Calculator while in development, was announced to the public on April 29, 1952, and was IBM’s first commercial scientific computer...
(Defense Calculator)
- Scientific (36-bit words): 704
The IBM 704, the first mass-produced computer with floating point arithmetic hardware, was introduced by IBM in 1954. The 704 was significantly improved over the IBM 701 in terms of architecture as well as implementations which were not compatible with its predecessor.Changes from the 701 included...
, 709The IBM 709 was an early computer system introduced by IBM in August, 1958. It was an improved version of the IBM 704 and the second member of the IBM 700/7000 series of scientific computers....
, 7090The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
, 7094, 7040The IBM 7040 was a historic but short-lived model of transistor computer built in the 1960s.It was announced by IBM in December 1961, but did not ship until April, 1963. A later member of the IBM 700/7000 series of scientific computers, it was a scaled down version of the IBM 7090. It was not fully...
, 7044
- Commercial (variable length character strings): 702
The IBM 702 was IBM's response to the UNIVAC—the first mainframe computer using magnetic tapes. Because these machines had less computational power than the IBM 701 and ERA 1103, which were favored for scientific computing, the 702 was aimed at business computing.The system used electrostatic...
, 705, 7080The IBM 7080 was a variable word length BCD transistor computer in the IBM 700/7000 series commercial architecture line, introduced in August 1961, that provided an upgrade path from the vacuum tube IBM 705 computer....
- 1400 series (variable length character strings): 7010
- Decimal (10 digit words): 7070
IBM 7070 was a decimal architecture intermediate data processing system that was introduced by IBM in June 1960. It was part of the IBM 700/7000 series, and was based on discrete transistors rather than the vacuum tubes of the 1950s. It was the company's first transistorized stored-program...
, 7072, 7074
- Supercomputer (64-bit words): 7030
The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. The first one was delivered to Los Alamos National Laboratory in 1961....
"Stretch"
The 700 class used
vacuum tubeIn electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s, the 7000 class was
transistorizedA transistor computer is a computer which uses discrete transistors instead of vacuum tubes. The "first generation" of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky, and were unreliable. A "second generation" of computers, through the late 1950s and...
. All machines (like most other computers of the time) used
magnetic core memoryMagnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
; except for early 701 and 702 models, which used
CRT memoryThe Williams tube or the Williams-Kilburn tube , developed in about 1946 or 1947, was a cathode ray tube used to electronically store binary data....
. While the architectures differed, the machines in the same class shared electronics technologies and generally used the same peripherals. Tape drives were the
IBM 727The IBM 727 Magnetic Tape Unit was announced for the IBM 701 and IBM 702 on September 25, 1953. It became IBM's standard tape drive for their early vacuum tube era computer systems. Later vacuum tube machines and first-generation transistor computers used the IBM 729-series tape drive...
on vacuum tube machines and the
729The IBM 729 Magnetic Tape Unit was IBM's iconic tape mass storage system from the late 1950s through the mid 1960s. Part of the IBM 7 track family of tape units, it was used on late 700, most 7000 and many 1400 series computers...
on transistor machines. Both the vacuum tube and most transistor models used
card readers, card punchesA punched card reader or just card reader is a computer input device used to read data from punched cards. A card punch is a output device that punches holes in cards under computer control...
and
line printerThe line printer is a form of high speed impact printer in which one line of type is printed at a time. They are mostly associated with the early days of computing, but the technology is still in use...
s that were based on IBM
accounting machineThe tabulating machine was an electrical device designed to assist in summarizing information and, later, accounting. Invented by Herman Hollerith, the machine was developed to help process data for the 1890 U.S. Census...
technology and even included
plugboardA plugboard, or control panel , is an array of jacks, or hubs, into which patch cords can be inserted to complete an electrical circuit. Control panels were used to direct the operation of some unit record equipment...
control panels. Two later machines, the 7010 and the 7040/44, adopted peripherals from the midline
IBM 1400 seriesThe IBM 1400 series were second generation mid-range business decimal computers that IBM sold in the early 1960s. They could be operated as an independent system, in conjunction with IBM punched card equipment, or as auxiliary equipment to other computer systems.1400-series machines stored...
.
Early computers were sold without software. As operating systems began to emerge, having four different mainframe architectures plus the 1400 midline architectures became a major problem for IBM since it meant at least four different programming efforts were required.
The System/360 combined the best features of the 7000 and 1400 series architectures into a single design. However, some 360 models had optional features that allowed them to emulate the 1400 and 7000 instruction sets in microcode. One of the selling points of the
System/370The IBM System/370 was a model range of IBM mainframes announced on June 30, 1970 as the successors to the System/360 family. The series maintained backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the...
, introduced in mid-1970, was improved 1400/7000 series emulation, which could be done under operating system control rather than shutting down and restarting in emulation mode as was required on the 360s.
First architecture (701)
Known as the
Defense Calculator while in development in the IBM Poughkeepsie Laboratory, this machine was formally unveiled April 7, 1953 as the
IBM 701 Electronic Data Processing Machine.
Data formats
Numbers were either 36 bits or 18 bits long, only fixed point. (
See: Why 36 bits?Many early computers aimed at the scientific market had a 36-bit word length. This word length was just long enough to represent positive and negative integers to an accuracy of ten decimal digits . It also allowed the storage of six alphanumeric characters encoded in a six-bit character encoding...
)
- Fixed point numbers were stored in binary sign/magnitude format
A computer number format is the internal representation of numeric values in digital computer and calculator hardware and software.-Bits:The concept of a bit can be understood as a value of either 1 or 0, on or off, yes or no, true or false, or encoded by a switch or toggle of some kind...
.
Instruction format
InstructionsAn instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
were 18 bits long, single address.
- Sign (1 bit) – Whole word (-) or Half word (+) operand address
- Opcode (5 bits) – 32 instructions
- Address (12 bits) – 4096 Half word addresses
To expand the memory from 2048 to 4096 words, a 33rd instruction was added that used the most significant bit of its address field to select the bank. (This instruction was probably created using the "No OP" instruction, which appears to have been the only instruction with unused bits, as it originally ignored its address field. However documentation on this new instruction is not currently available.)
Registers
Processor registerIn 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 consisted of:
- AC - 38-bit Accumulator
In a computer's central processing unit , an accumulator is a register in which intermediate arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation to main memory, perhaps only to be read right back again for...
- MQ – 36-bit Multiplier-Quotient
Scientific Architecture (704/709/7090/7094)
Data formats
Numbers were 36 bits long, both fixed point and floating point. (
See: Why 36 bits?Many early computers aimed at the scientific market had a 36-bit word length. This word length was just long enough to represent positive and negative integers to an accuracy of ten decimal digits . It also allowed the storage of six alphanumeric characters encoded in a six-bit character encoding...
)
- Fixed point numbers were stored in binary sign/magnitude format
A computer number format is the internal representation of numeric values in digital computer and calculator hardware and software.-Bits:The concept of a bit can be understood as a value of either 1 or 0, on or off, yes or no, true or false, or encoded by a switch or toggle of some kind...
.
- Single precision floating point
In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
numbers had a magnitude sign, an 8-bit excess-128 exponent and a 29 bit magnitude
- Double precision floating point numbers, introduced on the 7094, had a magnitude sign, a 17-bit excess-65536 exponent, and a 54 bit magnitude
- Alphameric
Alphanumeric is a combination of alphabetic and numeric characters, and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection. There are either 36 or 62 alphanumeric characters. The alphanumeric character set consists of the numbers 0 to...
characters were 6-bit BCD, packed six to a word.
Instruction format
The basic
instruction formatAn instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
was a 3-bit
prefix, 15-bit
decrement, 3-bit
tag, and 15-bit
address. The prefix field specified the class of instruction. The decrement field often contained an immediate operand to modify the results of the operation, or was used to further define the instruction type. The three bits of the tag specified three (seven in the 7094)
index registerAn index registerCommonly known as a B-line in early British computers. in a computer's CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations...
s, the contents of which were
subtracted from the address to produce an
effective address. The address field either contained an address or an immediate operand.
Registers
Processor registerIn 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 consisted of:
- AC - 38-bit Accumulator
In a computer's central processing unit , an accumulator is a register in which intermediate arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation to main memory, perhaps only to be read right back again for...
- MQ – 36-bit Multiplier-Quotient
- XR - 15-bit Index Registers (three or seven)
- SI - 36-bit Sense Indicator
The accumulator (and multiplier-quotient) registers operated in
signed magnitudeA computer number format is the internal representation of numeric values in digital computer and calculator hardware and software.-Bits:The concept of a bit can be understood as a value of either 1 or 0, on or off, yes or no, true or false, or encoded by a switch or toggle of some kind...
format.
The Index registers operated using
two's complementThe two's complement of a binary number is defined as the value obtained by subtracting the number from a large power of two...
format and when used to modify an instruction address were
subtracted from the address in the instruction. On machines with three index registers, if the tag had 2 or 3 bits set (i.e. selected multiple registers) then their values were ORed together before being subtracted. The IBM 7094, with seven index registers had a "compatibility" mode to permit programs from earlier machines that used this trick to continue to be used.
The Sense Indicators permitted interaction with the operator via panel switches and lights.
Memory
- 704
- 4,096 or 8,192 or 32,768 – 36-bit binary words with six-bit characters
- 709, 7090, 7094, 7094 II
- 32,768 – 36-bit binary words with six-bit characters
Input/output
The 709/7090 series used
Data Synchronizer Channels for high speed input/output, such as tape and disk. The DSCs executed their own simple programs from the computer memory that controlled the transfer of data between memory and the I/O devices.
Punched cardA punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
I/O and
high speed printingThe line printer is a form of high speed impact printer in which one line of type is printed at a time. They are mostly associated with the early days of computing, but the technology is still in use...
were often performed by transferring magnetic tapes to an off-line
IBM 1401The IBM 1401 was 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 electromechanical unit record equipment for processing data stored on punched cards...
. Later, the data channels were used to connect an 7094 and a 7044 to form the
IBM 7094/7044 Direct Coupled System (DCS). In that configuration, the 7044 primarily handled I/O.
FORTRAN assembly program
The
FORTRANFortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
Assembly Program (FAP) was the default macro assembler for the 709, 7090, and 7094.
Its pseudo-operation
BSS, used to reserve memory, is the origin of the common name of the "BSS section", still used in many
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...
s today for designating reserved memory
addressA digital computer's memory, more specifically main memory, consists of many memory locations, each having a memory address, a number, analogous to a street address, at which computer programs store and retrieve, machine code or data. Most application programs do not directly read and write to...
ranges of the type not having to be saved in the
executableIn computing, an executable file causes a computer "to perform indicated tasks according to encoded instructions," as opposed to a data file that must be parsed by a program to be meaningful. These instructions are traditionally machine code instructions for a physical CPU...
image.
Commercial architecture (702/705/7080)
The
IBM 702 and
IBM 705 were similar and the 705 could run many 702 programs without modification, but they were not completely compatible.
The
IBM 7080 was a transistorized version of the 705, with various improvements. For backward compatibility it could be run in
705 I mode,
705 II mode,
705 III mode, or full 7080 mode.
Data format
Data was represented by a variable length string of characters terminated by a
Record mark.
Registers
- 702
- two Accumulators (A & B) – 512 characters
- 705
- one Accumulator – 256 characters
- 14 auxiliary storage units – 16 characters
- one auxiliary storage unit – 32 characters
- 7080
- one Accumulator – 256 characters
- 30 auxiliary storage units – 512 characters
- 32 communication storage units – 8 characters
Memory
- 702
- 2,000 to 10,000 characters in Williams tube
The Williams tube or the Williams-Kilburn tube , developed in about 1946 or 1947, was a cathode ray tube used to electronically store binary data....
s (in increments of 2,000 characters)
- Character cycle rate – 23 microseconds
- 705 (models I, II, or III)
- 20,000 or 40,000 or 80,000 characters of Core memory
- Character cycle rate – 17 microseconds or 9.8 microseconds
- 7080
- 80,000 or 160,000 characters of Core memory
- Character cycle rate – 2.18 microseconds
1400 series architecture (7010)
The 700/7000 commercial architecture inspired the very successful
IBM 1400 seriesThe IBM 1400 series were second generation mid-range business decimal computers that IBM sold in the early 1960s. They could be operated as an independent system, in conjunction with IBM punched card equipment, or as auxiliary equipment to other computer systems.1400-series machines stored...
of mid-sized business computers. In turn, IBM later introduced a mainframe version of the
IBM 1410The IBM 1410, a member of the IBM 1400 series, was a variable wordlength decimal computer that was announced by IBM on September 12, 1960 and marketed as a midrange "Business Computer". It was withdrawn on March 30, 1970. The 1410 was similar in design to the very popular IBM 1401, but it had one...
called the IBM 7010.
Data format
Data was represented by a variable length string of characters terminated by a
WordmarkA wordmark, word mark or logotype is a standardized text logo or graphic representation of the name of a company, institution, or product name used for purposes of identification and branding. A wordmark is usually a distinct text-only typographic treatment as can be found in the graphic identities...
.
Decimal architecture (7070/7072/7074)
The
IBM 7070IBM 7070 was a decimal architecture intermediate data processing system that was introduced by IBM in June 1960. It was part of the IBM 700/7000 series, and was based on discrete transistors rather than the vacuum tubes of the 1950s. It was the company's first transistorized stored-program...
,
IBM 7072, and
IBM 7074 were decimal, fixed word length machines. They used a ten digit word like the smaller and older
IBM 650The IBM 650 was one of IBM’s early computers, and the world’s first mass-produced computer. It was announced in 1953, and over 2000 systems were produced between the first shipment in 1954 and its final manufacture in 1962...
, but were not
instruction setAn instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
compatible with the 650.
Data format
- Word length – 10 decimal digit plus sign
- Digit encoding – two-out-of-five code
In telecommunication, a two-out-of-five code is an m of n code that provides exactly ten possible combinations, and thus is popular for representing decimal digits using five bits...
- Floating point – optional. Two digit exponent.
- Three signs for each word – Plus, Minus and Alpha
- Plus and Minus indicated 10 digit numeric values.
- Alpha indicated 5 characters of text coded by pairs of digits. 61 = A, 91 = 1.
Instruction format
- All instructions one word
- 2 digit op code (including sign, Plus or Minus only)
- 2 digit index register
- 2 digit field control – allows selecting sets of digits, shifting left or right
- 4 digit address
Registers
- All registers one word, could also be addressed as memory
- Accumulators – 3 (addresses 9991, 9992, and 9993 – standard; 99991, 99992, and 99993 – extended 7074)
- Program register – 1 (address 9995 – standard; 99995 – extended 7074)
- Addressable from console only. Stores current instruction.
- Instruction counter – 1 (address 9999 – standard; 99999 – extended 7074)
- Addressable from console only.
- Index registers – 99 (addresses 0001-0099)
Memory
- 5000 to 9990 words (standard)
- 15000 to 30000 words (extended 7074)
- Access time – 6 microseconds (7070/7072), 4 microseconds (7074)
- Add time – 72 microseconds (7070), 12 microseconds (7072), 10 microseconds (7074)
IBM 700 series, vacuum tubeIn electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s, 1950s
- IBM 701
The IBM 701, known as the Defense Calculator while in development, was announced to the public on April 29, 1952, and was IBM’s first commercial scientific computer...
– IBM's first electronic computer – introduced in 1952
- IBM 702
The IBM 702 was IBM's response to the UNIVAC—the first mainframe computer using magnetic tapes. Because these machines had less computational power than the IBM 701 and ERA 1103, which were favored for scientific computing, the 702 was aimed at business computing.The system used electrostatic...
– commercial – introduced in 1953
- IBM 704
The IBM 704, the first mass-produced computer with floating point arithmetic hardware, was introduced by IBM in 1954. The 704 was significantly improved over the IBM 701 in terms of architecture as well as implementations which were not compatible with its predecessor.Changes from the 701 included...
– scientific – introduced in 1954
- IBM 705 – commercial – introduced in 1954
- IBM 709
The IBM 709 was an early computer system introduced by IBM in August, 1958. It was an improved version of the IBM 704 and the second member of the IBM 700/7000 series of scientific computers....
– scientific – introduced in 1958
IBM 7000 series, transistorA transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s, 1960s
- IBM 7010 – high end version of IBM 1410
The IBM 1410, a member of the IBM 1400 series, was a variable wordlength decimal computer that was announced by IBM on September 12, 1960 and marketed as a midrange "Business Computer". It was withdrawn on March 30, 1970. The 1410 was similar in design to the very popular IBM 1401, but it had one...
– introduced in 1962
- IBM 7030
The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. The first one was delivered to Los Alamos National Laboratory in 1961....
– Stretch supercomputer – introduced in 1961
- IBM 7040
The IBM 7040 was a historic but short-lived model of transistor computer built in the 1960s.It was announced by IBM in December 1961, but did not ship until April, 1963. A later member of the IBM 700/7000 series of scientific computers, it was a scaled down version of the IBM 7090. It was not fully...
– scientific – introduced in 1963
- IBM 7044 – scientific – introduced in 1963
- IBM 7070
IBM 7070 was a decimal architecture intermediate data processing system that was introduced by IBM in June 1960. It was part of the IBM 700/7000 series, and was based on discrete transistors rather than the vacuum tubes of the 1950s. It was the company's first transistorized stored-program...
– decimal – introduced in 1960
- IBM 7072 – decimal – introduced in 1962
- IBM 7074 – decimal – introduced in 1961; used by the U.S. Internal Revenue Service
The 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...
in 1962
- IBM 7080
The IBM 7080 was a variable word length BCD transistor computer in the IBM 700/7000 series commercial architecture line, introduced in August 1961, that provided an upgrade path from the vacuum tube IBM 705 computer....
– commercial – introduced in 1961
- IBM 7090
The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
– scientific – introduced in 1959
- IBM 7094 – scientific – introduced in 1962
- IBM 7094 II – scientific – introduced in 1964
The
IBM 7700 Data Acquisition SystemThe IBM 7700 Data Acquisition System was announced by IBM on December 2, 1963.It was capable of collecting data from as many as 32 sources simultaneously, process the data and transmit results to up to 16 remote printers, display units or plot boards....
was not a member of the IBM 7000 series, despite its number and its announcement date of December 2, 1963.
External links