|
IBM 2560
The IBM System/360 Model 20 is the smallest member of the IBM System/360 family announced in November 1964. The Model 20 supports only a subset of the System/360 instruction set, with binary numbers limited to 16 bits and no floating point. In later years it would have been classified as a 16-bit minicomputer rather than a mainframe, but the term "minicomputer" was not current, and in any case IBM wanted to emphasize the compatibility of the Model 20 rather than its differences from the rest of the System/360 line. It does, however, have the full System/360 decimal instruction set, that allows for addition, subtraction, product, and dividend of up to 31 decimal digits. Developed by IBM in Böblingen, Germany, the system was intended for data processing and as a replacement for tab equipment. An incompatible small computer, the IBM 1130 introduced the following year, was designed for scientific and engineering computing. The design of the Model 20 was the result of a tug of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1442
IBM 1442 is a combination IBM card reader and card punch. It reads and punches 80-column IBM-format punched cards and is used on the IBM 1440, the IBM 1130, the IBM 1800 and System/360 and is an option on the IBM System/3. Overview The 1442 can read up to 400 cards per minute. Cards are read and punched one column at a time and binary cards are permitted. Cards are read using photocells, illuminated by fiber optics, unlike the IBM 1402, which uses wire brushes to read cards. It is even possible to create (but not read, except in Binary Mode) " IBM Doilies," cards with every possible hole punched. Few other pieces of IBM equipment could do this without sustaining damage. There are two output stackers, located in the photo on the left lower side. One could program to select the output stacker for each card read, so it is possible to read cards and separate them into two groups. Cards are placed in the top hopper ("face down, nine-edge leading") and a plate is added on the top of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 in that architecture identify the operand(s) of each instruction. An addressing mode specifies how to calculate the effective memory address of an operand by using information held in registers and/or constants contained within a machine instruction or elsewhere. In computer programming, addressing modes are primarily of interest to those who write in assembly languages and to compiler writers. For a related concept see orthogonal instruction set which deals with the ability of any instruction to use any addressing mode. Caveats Note that there is no generally accepted way of naming the various addressing modes. In particular, different authors and computer manufacturers may give different names to the same addressing mode, or the same na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronous Transmit-receive
Synchronous transmit-receive (STR) was an early IBM character-oriented communications protocol which preceded Bisync. STR was point-to-point only, and employed a ''four-of-eight'' transmission code, communicating at up to 5100 characters per second over half-duplex or full-duplex communication lines. The IBM 1009 Data Transmission Unit, the IBM 1130 Synchronous Communications Adapter, the IBM System/360 model 20 Communications Adapter, and the IBM 2701 Data Transmission Unit provided host computer support for STR. The IBM 7701, the IBM 7702 Magnetic Tape Transmission Terminal, the IBM 1013 Card Transmission Terminal, and the IBM 7710 and IBM 7711 Data Communication Units were among the remote devices supported by STR. STR was still supported as of 1972, although it had generally faded from use. Four-of-eight code The four-of-eight code was a 64 character set plus six control characters, encoded in eight bits. Like other kinds of 6b/8b encoding, exactly four bits of each ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 2501
The IBM 2501 is a punched-card reader from IBM with models for the System/360 and System/370 mainframe systems and for the IBM System/360 Model 20, the IBM 1130 and IBM System/3 minicomputers. 2501 models can read 80-column cards at either 600 or 1000 cards per minute (CPM). The 2501 is no longer sold, but is simulated in software on current IBM systems. Models The 2501 comes in four models depending on speed and attachment features. Models for mainframe use come with an ''integrated control unit'' that performs the functions of a control unit required by other devices. The A1 and A2 are for the IBM 1130. Usage The 2501 uses a photoelectric sensor to read the data punched in the card. Cards are read ''serially'' (column by column) and the reader uses a simplified "straight through" card path. "Each column is read twice and the two readings are compared to check reading accuracy." In a mainframe environment the 2501 was frequently used for mainframe input in an "open shop" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1403
The IBM 1403 line printer was introduced as part of the IBM 1401 computer in 1959 and had an especially long life in the IBM product line. Description The original model can print 600 lines of text per minute and can skip blank lines at up to 75 inches per second (190 cm/s), while the model 3 can print at up to 1400 lines per minute. The standard model has 120 print positions. An additional 12 positions are available as an option. A print chain with up to 15 copies of the character set spins horizontally in front of the ribbon and paper. Hammers strike the paper from behind at exactly the right moment to print a character as it goes by. In later models, the print chain is replaced by a print train; print slugs instead of being mounted on a chain are placed in a track. The 1403 chain or train contains 240 characters, however numerous duplications allow a line to be printed in less than the 0.4 s required for one full rotation. The original standard "A" chain co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 2311
IBM manufactured magnetic disk storage devices from 1956 to 2003, when it sold its hard disk drive business to Hitachi. Both the hard disk drive (HDD) and floppy disk drive (FDD) were invented by IBM and as such IBM's employees were responsible for many of the innovations in these products and their technologies. The basic mechanical arrangement of hard disk drives has not changed since the IBM 1301. Disk drive performance and characteristics are measured by the same standards now as they were in the 1950s. Few products in history have enjoyed such spectacular declines in cost and physical size along with equally dramatic improvements in capacity and performance. IBM manufactured 8-inch floppy disk drives from 1969 until the mid-1980s, but did not become a significant manufacturer of smaller-sized, 5.25- or 3.5-inch floppy disk drives (the dimension refers to the diameter of the floppy disk, not the size of the drive). IBM always offered its magnetic disk drives for sale but did no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Tape Data Storage
Magnetic-tape data storage is a system for storing digital information on magnetic tape using digital recording. Tape was an important medium for primary data storage in early computers, typically using large open reels of IBM 7 track, 7-track, later 9-track tape, 9-track tape. Modern magnetic tape is most commonly packaged in cartridges and cassettes, such as the widely supported Linear Tape-Open (LTO) and IBM 3592 series. The device that performs the writing or reading of data is called a tape drive. Autoloader (data storage device), Autoloaders and tape library, tape libraries are often used to automate cartridge handling and exchange. Compatibility was important to enable transferring data. Tape data storage is now used more for system backup, data archive and data exchange. The low cost of tape has kept it viable for long-term storage and archive. Open reels Initially, magnetic tape for data storage was wound on reels. This standard for large computer systems persis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral
A peripheral or peripheral device is an auxiliary device used to put information into and get information out of a computer. The term ''peripheral device'' refers to all hardware components that are attached to a computer and are controlled by the computer system, but they are not the core components of the computer, such as the CPU or power supply unit. In other words, peripherals can also be defined as devices that can be easily removed and plugged into a computer system. Several categories of peripheral devices may be identified, based on their relationship with the computer: *An ''input device'' sends data or instructions to the computer, such as a mouse, keyboard, graphics tablet, image scanner, barcode reader, game controller, light pen, light gun, microphone and webcam; *An ''output device'' provides output data from the computer, such as a computer monitor, projector, printer, headphones and computer speaker; *An ''input/output device'' performs both input and output fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformer Read-only Storage
Transformer read-only storage (TROS) was a type of read-only memory (ROM) used in the 1960s and early 1970s before solid-state memory devices were developed. Overview TROS was created by IBM as a read-only storage method for storing microcode for IBM computers. TROS used stacks of removable Mylar flexible printed wiring sheets that fitted onto fixed transformer bases. It was used on the IBM System/360 Model 20, IBM System/360 Model 40 and the Type 2841 file control unit. Use TROS memory was used to store microcode for mainframe computer A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterpris ...s and intelligent controllers used to control sophisticated storage devices such as disk drives and tape drives. If there were a bug in the microcode it was possible to rework it by replacing one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
