Office Systems

III

Computers

During the first half of the 20th century, most office tasks were performed either manually or by using electromechanical devices. Since the late 1950s computers have taken over those tasks, to the extent that they now dominate business operations. Early computers were large, expensive, and difficult to maintain. They were predominantly used for heavy volume data processing applications. Typically, one computer would be shared by many users so that the costs could be minimized.

Mainframe computers with remote terminals, each with its own monitor, became available by the mid-1970s. This allowed simultaneous use by many users. The advent of the minicomputer dramatically reduced the cost of computing and made it possible for individuals to have their own personal computer (PC). Desktop PCs have become increasingly affordable, as a result of industry-wide adoption of the PC architecture, introduced in 1981.

Although feasible to provide virtually every office worker with a PC, it is more effective to retain some form of centralization in office computer systems. This means that expensive peripherals such as printers and scanners are shared. It also means that groups of workers can access each other’s files and have centrally managed file stores. Since the late 1980s, many companies have been linking, or networking, multiple PCs into a unified system.

The local area network (LAN) was created in response to the need for a standardized system of linking computers. Installing cables that connect each computer to a network is the most common linking method, but other means have been used, such as infrared radiation, radio frequency waves, and as a conducting medium, a building’s electrical wiring system. The most commonly adopted LAN for office networking is Ethernet. This allows many users to access shared resources via a single cable. The control, facilities, and administration on a LAN are controlled using network software, such as Novell NetWare, which is usually loaded on a network server (a computer connected to the network). The sophistication of modern LAN products provides a rich and flexible working environment in many offices that allows users to select the resources such as printers and file stores they wish to use.

Where computers are more than a few kilometres apart LANs cannot be used, and some form of wide area network (WAN) is required. This usually means using telephone lines, although emerging data networks operate at speeds comparable to those used on LANs (around 10 megabytes per second).

IV

Document Reproduction

Office machines for the full-size production of documents can be divided into two groups: copiers designed to make one or more reproductions, and duplicators designed to make many copies. Despite the fact that many companies now store much of their documentation electronically, or on film, they still store a lot of paper documents. Most experiments with paperless offices have concluded that people prefer to use paper for some purposes, so it seems unlikely that offices will ever become wholly electronic.

A

Copiers and Duplicators

Most modern copiers are electrostatic devices in which document images are created by means of electrical charges and powdered ink, or toner, particles. In the electrophotographic process, the most common photocopying method, a mirror image of a printed page is induced electrostatically on to a metal cylinder from which it is then transferred to a sheet of plain paper.

Copier speeds range from a few pages per minute to more than two pages per second. Advanced devices are equipped with automatic feeders, collators, and staplers. Some machines can copy both sides of a document automatically, reduce or enlarge the image, and faithfully reproduce colour images. Increasingly, copiers are connected to a network so that they can report the results of diagnostic tests to the supplier, thus making preventive maintenance feasible.

Instead of electrostatic technology, some duplicators employ offset lithography, in which a specially prepared master is used to produce multiple copies. Offset printing, using small presses, is the printing technique most often used in modern business offices, usually in large organizations that have a central printing department with trained personnel.

Previously common copying and duplicating processes retain a very limited role in the office nowadays, but still may be found in schools and other institutions. In spirit duplication, a master bearing images formed from carbon dye is moistened with an alcohol solution, dissolving some of the dye, which is then deposited on a piece of paper. This process is repeated rapidly for multiple copies. In mimeography, a stencil-like master is created by typing or otherwise removing an ink-impervious coating from a fibrous tissue. The master is mounted on a cylinder that forces ink through the stencil on to the paper. The diazo process uses ammonia-sensitive paper to produce large-scale offprints. This is still used in some engineering and architectural offices.

B

Computer Printers

A considerable volume of office computer output is channelled via the printer. Among the earliest printers used with PCs were daisy wheel and thimble printers, so called because of the shape of their printing elements. These produced output in a similar way, and quality comparable to that produced by a typewriter. They were, however, slow and could accommodate only text, not graphics. As a result, they have been supplanted in most offices by laser printers, which have largely replaced dot-matrix and ink-jet printers. The dot-matrix printer impacts the paper through a ribbon to create a pattern of dots in the shape of letters and numbers of varying fonts and sizes. The ink-jet printer operates in a similar way, but provides higher resolution and quieter operation. The laser printer provides much higher quality. It operates much like a photocopier, offers a resolution of 300 dots or more per inch, can reproduce complex graphics, can print a page of text in about one second, and is virtually silent. These attributes make the laser printer virtually indispensable for desktop publishing and most offices have at least one such device connected to their internal network.

V

Communications

A common means of textual messaging between offices is by fax. This precursor of electronic mail converts the dark and light areas on a page into digital code. At the receiving site, the incoming signal is decoded to produce a replica of the transmitted information. Fax can be used to send any image that can be put into the fax machine and scanned—pictures as well as text. It is now commonplace for fax transmissions to be initiated from a computer. This removes the need to print a document from a computer and then send it via the fax machine.

Electronic mail (e-mail) takes this one step further by transmitting structured data rather than the code generated by scanning an image. E-mail has become a key part of the communications network of most modern offices. It allows messages to be transmitted from one computer to others using some form of telecommunications link. There are now many e-mail products in the marketplace, with the most pervasive and influential driver of electronic communication being the Internet.