Chips

A chip is an integrated circuit. Microscopic circuit board is engraved in a chip made by silicon. Chips are approximately 1/16- to 1/2-inch square and about 1/30-inch thick. Chips hold a few dozen to several million transistors. For example, an Intel Pentium chip has 3.2 million and Pentium Pro has about 6 million transistors. A chip is also called an integrated circuit, microelectronic, semiconductor, or silicon chip.

Peripheral

A peripheral is any hardware device connected to, controlled by and communicates with a particular computer. It is also called peripheral device and peripheral equipment. For example, it is an input/output unit such as a keyboard, monitor, printer, scanner and mouse. Another example is an auxiliary storage device such as a disk drive, tape drive and optical disk drive.

MIPS

MIPS stands for Million Instructions Per Second. This is the execution speed of a computer. For example, 0.3 MIPS is 300,000 instructions per second. A large mainframe works at 10 to 50 MIPS, whereas a typical microprocessor can perform at around 0.05 MIPS. However, it must be taken carefully. MIPS rate, which is tied to the computer's clock speed, is only one factor in overall performance. Bus and channel speed, disk and memory speed, memory management techniques and operating system also determine total performance of a computer system.

Coprocessor chip

This is one of the specialized processors. A mathematics coprocessor chip that assists the main processor can help a CPU do very fast mathematical computations. The coprocessor is controlled by the main microprocessor.

Registers

A register is a small, high speed circuit that builds special high speed staging areas. This circuit holds data and instructions of internal operation temporarily during processing. They are parts of the control unit and ALU rather than primary storage. Register can handle addresses and values much faster than primary storage can.

ROM BIOS(Read Only Memory Basic Input Output System)

A set of routines stored in a ROM chip in a PC. The BIOS contains the drivers, or access methods, which activate the peripheral devices directly.

Memory Does Not Remember?

Primary storage holds its contents only temporarily - only as long as a microcomputer is turned on. When the machine is turned off, all the stored contents immediately vanish. It is therefore a good practice repeatedly to save your work in progress to a secondary storage device.

Capacity

RAM storage is usually represented in megabytes. For example, the IBM or IBM compatible PC that has 16 Megabyte of memory can hold 16 million characters. If a user uses a computer with small primary storage, he or she cannot run programs that require large memory such as later versions of WordPerfect for Windows, Photoshop or graphics software. Thus, the user had better check the amount of RAM when he or she buy a computer. A user also need to check the required RAM before he or she buys a software package.

Addresses

To locate the characters of data or instructions in memory, the computer stores them at locations known as addresses. Each address has a unique number. Addresses may be compared to post office mailboxes. Their numbers stay the same, but the contents continually change.

SIMM

Single In-line Memory Module (SIMM) is a narrow printed circuit board that holds many (8, 9, 12, etc.) memory chips. The card has either 30 pins or 72 pins.

SCSI Card

Small Computer System Interface (SCSI) controller card provides high-speed, parallel data transfer and multiple peripheral connections up to seven devices.

Fast SCSI

Fast SCSI provides 10MB data transfer through an 8-bit-bus.

Wide SCSI

Wide SCSI provides up to 40MB transfer speed with a secondary "B" cable for 16-bit and 32-bit data.

DB-9/DB-25

Plugs and sockets (connectors) with 9 and 25 pins respectively. These connectors are commonly used for RS-232 interfaces. The same DB-25 connector used in RS-232 serial cables is also used as a connector for parallel printer cables.

VESA (Video Electronics Standards Association)

VESA is an organization of major PC graphics vendors devoted to improving graphics standards. It is involved with video controller, monitor and multimedia standards, including VGA, Super VGA.

File

In word processing, a file is a single document. In computer graphics, a file is a set of image descriptors for one picture. In a database, a file is a collection of records.

Read-Write Head

A device that reads and writes data on a magnetic disk. For writing, the surface of the disk is moved past the read/write head. Bits of data are recorded as tiny, magnetized spots of positive or negative polarity, by discharging electrical impulses at the appropriate times. For reading, the bits on a disk induce an electrical current across the read head.

Access arm

This is a mechanical arm that moves the read/write head across the surface of a disk. The access arm is directed by the operating system to move the read/write head to a specific track on the disk.

Tightly Sealed Container

A hard disk is enclosed in a tightly sealed container. The reason is to prevent any foreign material from getting inside. The read-write head rides on a cushion of air about 0.000001- inch thick. It is so thin that a smoke particle, fingerprint, or human hair could cause a head crash.

Head Crash

This is a physical destruction of a hard disk. Misalignment or contamination with dust can cause the read/write head to collide with the disk's recording surface. The head crash destroys all or part of data on the disk.

Hardcard

A hardcard is a circuit board with a disk that plugs into an expansion slot in the computer. The card is only 1-inch-thick. This can be an alternative to the external hard-disk drives.

CD-ROM XA

CD-ROM eXtended Architecture is an extension of the CD-ROM standard that allows for audio to be played concurrently while viewing data. CD-ROM XA uses a standard CD-ROM player, but requires a CD-ROM XA controller card in the computer.

DAT

Digital Audio Tape is a technology to record data using digital recording technology on a small magnetic tape. A 4mm-DAT drive holds 2 GB or more.

Pen-Based Computing

This computing technology recognizes handwriting and has software that recognizes and digitizes handwriting and handdrawing.

Kiosks

A stand alone information delivery system that often uses a touch screen as an input device. For example, kiosks are found in an airport for users to get information on car rentals, hotel reservations and travel information.

Track ball

An input device used in graphics applications and as a mouse alternative when no flat surface is available. It is a stationary unit that contains a rolling ball that is rotated with the fingers and, correspondingly, moves the cursor on the screen.

Recent Trends of the TERMINALs

A recent trend has been the use of microcomputers as terminals. As prices of microcomputers have dropped, companies have tended to buy intelligent terminals (microcomputers) instead of dumb terminals. It is because microcomputers can work exactly like dedicated terminals with the appropriate software and communications links.