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Tape drive
A storage device designed to back up data from another storage device onto magnetic Tape at a high rate of speed. Data is stored sequentially (no random access).  Tape drives are ideal for backing up and archiving files because the cartridges used in these drives are less expensive than other media.  The most common types of Tape devices are: Quarter-Inch Cartridge (QIC), Digital Audio Tape (DAT), and 8mm Helical Scan.

A device that responds to commands from a device (the initiator).

Transmission Control Protocol, the reliable internet transport protocol.

The electrical connection required at each end of the SCSI bus, composed of a set of resisters. It improves the integrity of bus signals.

A screen and keyboard combination device used to interact with a computer.   Terminals are usually used to access a mainframe computer.

Terminate and Stay Resident
See TSR.

An electrical circuit attached to each end of a SCSI bus to minimize signal reflections and extraneous noise.  To ensure reliable communication, the SCSI bus must be properly terminated. Termination is controlled by a set of electrical resistors divider networks (Passive Terminator) or a resistors with precision voltage reference to pull-up the SCSI line (Active Terminator), call Terminator. Terminators must be placed (or Enabled) at the two extreme ends of the SCSI bus. All devices that lie between the ends must have their terminators removed (or Disabled).

Terminators (active)
Rather than passive terminators that use TERMPWR which may not be exactly +5v, active terminators use a voltage regulator.

Terminators (passive)
A group of resistors on the physical ends of a single ended SCSI-bus(and only on these ends) that dampens reflected signals from the ends of the bus. Each terminated signal is connected by

* 220 Ohm to +5 volt (TERMPWR)

* 330 Ohm to ground.

The 18 signals that are terminated are

I/O, Req, C/D, Sel, Msg, Rst, Ack, Bsy, Atn, DB(p), DB(7) ... DB(0).

Terminator power. SCSI TERMPWR is a diode drop below the supply voltage (5 Volts).

The physical layout of network cabling.

Terminate and Stay Resident. A program that resides dormant in the computer's memory until triggered by another program or by a device.

The TWAIN programming interface, developed by the TWAIN Working Group, specifies how applications communicate with data sources via a module called TWAIN.DLL. In most cases, you can think of a data source as a scanner driver. Using TWAIN, an application doesn't require any information about the data source and vice versa.

Twisted Pair
Two wires twisted together to reduce susceptibility to RF noise.

Twisted-Pair Flat Cable
A group of twisted pairs of wires arranged in rows that comprise a single flat cable.  Twisted-pair flat cables are less susceptible to noise than are ribbon cables.


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