Controller (computing)
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In computing and especially in computer hardware, controller is a chip, an expansion card, or a stand-alone device that interfaces with a peripheral device. This may be a link between two parts of a computer (for example a memory controller that manages access to memory for the computer) or a controller on an external device that manages the operation of (and connection with) that device.
The term is sometimes used in the opposite sense to refer to a device by which the user controls the operation of the computer, as in game controller.
In desktop computers the controller may be a plug in board, a single integrated circuit on the motherboard, or an external device. In mainframes the controller is usually either a separate device attached to an channel or integrated into the peripheral.
Controller chips
- Keyboard controller
- Programmable Interrupt Controller
- Northbridge (computing) – Intel memory controller chip
- Southbridge (computing) – Intel I/O controller chip
- Universal asynchronous receiver/transmitter (UART) communications controller chip
- Memory controller, logic which manages the flow of data in a computer system
- Peripheral DMA controller
- Floppy disk controller
Controller boards
- Graphics controller or video display controller
- SCSI controller, more properly called SCSI host bus adapter
- Network interface controller (NIC)
External controllers
- Disk controller, often integrated into modern disk drives.
- Disk array controller, also known as RAID controller, a type of storage controller
- Flash controller, or SSD controller, manages flash memory.
- Terminal Access Controller
Mainframe controllers
In IBM terminology a controller is "a device that decodes the [channel] command and effects the operation of the device."[2]: p.5-1
In most mainframe systems a device-independent channel usually attaches to the CPU and a controller or control unit implements device-dependent logic for attaching specific devices to the channel. Some devices have integrated control units.
- IBM 2821 Control Unit, used to attach card readers, punches and line printers to IBM System/360 and IBM System/370 computers
- IBM 270x and IBM 37xx, used for telecommunications
- IBM 3271, 3272, 3271, and 3174, used to attach terminals (display devices)
See also
- Adapter (computing)
- Programmable logic controller
- Computer bus
- Super I/O
- Control unit (disambiguation)
- MIDI controller
References
- ^ IBM Corporation. IBM Systems Reference Library IBM 1311 Disk Storage Drive (PDF).
- ^ IBM Corporation (1978). Introduction to IBM Data Processing Systems (PDF).
External links
- Controller description at Webopedia, a computer term dictionary.
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