7AK7 | |
---|---|
Classification | Pentode |
Service | Digital computers |
Height | 3+5⁄32 in (80 mm) |
Diameter | 1+3⁄16 in (30 mm) |
Cathode | |
Cathode type | Coated Unipotential |
Heater voltage | 7.0 V (6.3 V nominal) |
Heater current | 800 mA |
Anode | |
Max dissipation Watts | 8.5 W |
Max voltage | 200 V |
Socket connections | |
Pin 1 – Heater | |
References | |
https://web.archive.org/web/20221114011216/http://www.nj7p.org/Tubes/PDFs/Frank/137-Sylvania/7AK7.pdf |
The 7AK7 is a pentode vacuum tube (thermionic valve). According to its manufacturer, Sylvania, it was "designed for service in electronic computers". [1]
The tube was developed in 1948, [2] designed at the request of L. D. Wilson for use in the Whirlwind computer. [3] Significant attention was directed towards its manufacturing process in order to ensure the part's reliability. [4] Dubbed the "computer tube", [5] it became a popular tube for computers for a while. [2] IBM, however, switched to more compact miniature tubes, starting with the IBM 604 in 1948.
Computer science is the study of computation, information, and automation. Computer science spans theoretical disciplines to applied disciplines. Though more often considered an academic discipline, computer science is closely related to computer programming.
Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other electrically charged particles. Electronics is a subfield of electrical engineering, but it differs from it in that it focuses on using active devices such as transistors, diodes, and integrated circuits to control and amplify the flow of electric current and to convert it from one form to another, such as from alternating current (AC) to direct current (DC) or from analog to digital. Electronics also encompasses the fields of microelectronics, nanoelectronics, optoelectronics, and quantum electronics, which deal with the fabrication and application of electronic devices at microscopic, nanoscopic, optical, and quantum scales.
The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers.
The Williams tube, or the Williams–Kilburn tube named after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first random-access digital storage device, and was used successfully in several early computers.
A supercomputer is a computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instructions per second (MIPS). Since 2017, supercomputers have existed which can perform over 1017 FLOPS (a hundred quadrillion FLOPS, 100 petaFLOPS or 100 PFLOPS). For comparison, a desktop computer has performance in the range of hundreds of gigaFLOPS (1011) to tens of teraFLOPS (1013). Since November 2017, all of the world's fastest 500 supercomputers run on Linux-based operating systems. Additional research is being conducted in the United States, the European Union, Taiwan, Japan, and China to build faster, more powerful and technologically superior exascale supercomputers.
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 NCR Corporation (NCR), General Electric, and Honeywell, RCA and UNIVAC. For most of the 1960s, the strength of CDC was the work of the electrical engineer Seymour Cray who developed a series of fast computers, then considered the fastest computing machines in the world; in the 1970s, Cray left the Control Data Corporation and founded Cray Research (CRI) to design and make supercomputers. In 1988, after much financial loss, the Control Data Corporation began withdrawing from making computers and sold the affiliated companies of CDC; in 1992, Cray established Control Data Systems, Inc. The remaining affiliate companies of CDC currently do business as the software company Ceridian.
ENIAC was the first programmable, electronic, general-purpose digital computer, completed in 1945. There were other computers that had combinations of these features, but the ENIAC had all of them in one computer. It was Turing-complete and able to solve "a large class of numerical problems" through reprogramming.
The IBM 604 Electronic Calculating Punch was the world's first mass-produced electronic calculator along with its predecessor the IBM 603. It was an electronic unit record machine that could perform multiple calculations, including division. It was invented and developed by Ralph Palmer, Jerrier Haddad and Byron Phelps. It was introduced by IBM in 1948.
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 series scientific computers. The first 7090 installation was in December 1959. In 1960, a typical system sold for $2.9 million or could be rented for $63,500 a month.
A stored-program computer is a computer that stores program instructions in electronically or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechanisms.
The IBM 701 Electronic Data Processing Machine, known as the Defense Calculator while in development, was IBM’s first commercial scientific computer and its first series production mainframe computer, which was announced to the public on May 21, 1952. It was invented and developed by Jerrier Haddad and Nathaniel Rochester based on the IAS machine at Princeton.
The IBM Selective Sequence Electronic Calculator (SSEC) was an electromechanical computer built by IBM. Its design was started in late 1944 and it operated from January 1948 to August 1952. It had many of the features of a stored-program computer, and was the first operational machine able to treat its instructions as data, but it was not fully electronic. Although the SSEC proved useful for several high-profile applications, it soon became obsolete. As the last large electromechanical computer ever built, its greatest success was the publicity it provided for IBM.
Reliability, availability and serviceability (RAS), also known as reliability, availability, and maintainability (RAM), is a computer hardware engineering term involving reliability engineering, high availability, and serviceability design. The phrase was originally used by International Business Machines (IBM) as a term to describe the robustness of their mainframe computers.
A transistor computer, now often called a second-generation 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 unreliable. A second-generation computer, through the late 1950s and 1960s featured circuit boards filled with individual transistors and magnetic-core memory. These machines remained the mainstream design into the late 1960s, when integrated circuits started appearing and led to the third-generation computer.
Nathaniel Rochester was the chief architect of the IBM 701, the first mass produced scientific computer, and of the prototype of its first commercial version, the IBM 702. He wrote the first assembler and participated in the founding of the field of artificial intelligence.
The Manchester computers were an innovative series of stored-program electronic computers developed during the 30-year period between 1947 and 1977 by a small team at the University of Manchester, under the leadership of Tom Kilburn. They included the world's first stored-program computer, the world's first transistorised computer, and what was the world's fastest computer at the time of its inauguration in 1962.
Bruce Gilchrist is considered one of the notable figures in modern computing history.
Information technology (IT) is a set of related fields that encompass computer systems, software, programming languages and data and information processing and storage. IT forms part of information and communications technology (ICT). An information technology system is generally an information system, a communications system, or, more specifically speaking, a computer system — including all hardware, software, and peripheral equipment — operated by a limited group of IT users, and an IT project usually refers to the commissioning and implementation of an IT system.
A vacuum-tube computer, now termed a first-generation computer, is a computer that uses vacuum tubes for logic circuitry. While the history of mechanical aids to computation goes back centuries, if not millennia, the history of vacuum tube computers is confined to the middle of the 20th century. Lee De Forest invented the triode in 1906. The first example of using vacuum tubes for computation, the Atanasoff–Berry computer, was demonstrated in 1939. Vacuum-tube computers were initially one-of-a-kind designs, but commercial models were introduced in the 1950s and sold in volumes ranging from single digits to thousands of units. By the early 1960s vacuum tube computers were obsolete, superseded by second-generation transistorized computers.
The 5965 is a miniature twin triode vacuum tube. According to its manufacturer, Sylvania, it was “designed for use in high-speed digital computers”.