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Plugging in computer peripherals: with a SCSI, many devices can be run off the computer without a hitch.

Here's a typical historical log of an accountant determined to stay at the leading edge of technology:

1990: The accountant upgrades to a 386 personal computer (PC), which operates as a stand-alone. The only peripheral is a printer and the setup works flawlessly.

1991: The accountant's office adds a network, so a network card is installed in the computer, which continues to work flawlessly.

1993: The computer is upgraded to a 486 with Windows. Now, in addition to the network card and the printer, a mouse is added so the CPA can maneuver through Windows screens. There still is no problem.

1994: A fax-modern and a CD-ROM drive are added. That's when the computer begins to have problems, freezing on occasion. After several such occurrences, the CPA realizes the problem happens only when he tries to use the CD-ROM while the other peripherals are operating. The office technical support person blames the freezes on what she calls interrupt problems, which she explains are conflicting simultaneous commands that paralyze the computer. The support person tinkers with the computer setup and the problem seems to be solved. Some months later the accountant adds both a tape backup unit and a scanner. The freezing resumes. Again the diagnosis is interrupt problems and more tinkering is done. It helps, but occasional freezing persists.

Then, when a sound board and speakers are added so the audio generated by CD-ROM disks can be heard clearly, freezing occurs so frequently the office techie is tinkering with the computer a few times a week but making little progress.

Finally, in frustration, the accountant calls in an independent computer consultant who takes one look at the setup and says, "You need a SCSI (pronounced scuzzy) board." (SCSI is an acronym for small computer system interface. Once one is installed, the computer works flawlessly--even when all the peripherals are running.

This article is about the SCSI--a simple electronic component that can transform a powerful, but crippled, computer into a fully productive machine.


With the advent of powerful PCs, productivity-minded accountants quickly added peripherals such as CD-ROMs, tape backup drives, additional hard drives, fax-modems and scanners to their machines. Unfortunately, given the way most PCs are configured and the way most peripherals are designed, it's not possible to simply plug in a new component and expect it to run without a hitch. Recently, some computer makers have been claiming that their machines are "plug and play"--which means all the user has to do is plug in a peripheral and it'll play flawlessly. Suffice it to say there's a gap between advertised claims and experience. (That's not to say that sometime in the near future PCs and peripherals won't be designed with convenient plug-and-play features.

In the meantime, CPAs should consider installing SCSI boards. They can expand the capacity of stand-alone or networked PCs dramatically for a relatively low price.

Despite the praise heaped on SCSI technology, the devices often are difficult to install and certain configurations can interfere with existing software because hardware and software vendors have not agreed on standardized interface designs--that is, the components sometimes talk a slightly different language. But although they can be troublesome to set up, once they are configured, they work beautifully.

With a properly installed SCSI adapter card in a PC expansion slot (an internal plug designed to accommodate added peripherals), a user can connect up to seven peripherals. Multiple SCSI host adapter cards can be added to a PC, limited only by the number of available expansion slots in it. A typical PC may have between five and seven such slots. In theory, it's possible to add an infinite number of SCSI cards to a PC (it's called "nesting the chain"), but as a practical matter, such a design is not advisable because it requires complex custom software to solve compatibility problems.

Adding SCSI technology to an existing computer is not prohibitively expensive. For example, Adaptec, Future Domain and Ultrastor--leading SCSI vendors--sell SCSI host adapters from about $150 to ($450 (depending on configurations and options).


SCSI installation is generally not a do-it-yourself job; it's best to turn to an experienced technician. If new equipment is being purchased, one should insist that the peripherals be installed by the factory or the dealer and tested fully before delivery.

Here are some suggestions for those who decide to do it themselves:

* Keep it simple. Do not try to hook up a wide assortment of peripherals and expect them to work harmoniously with existing software and hardware. Begin, for example, with a SCSI hard drive or perhaps a tape backup unit, both of which are relatively simple to install.

* Add one device at a time. A simple, sequential approach is likely to ward off many potential problems.

* Do not boot (turn on) your computer without turning on the SCSI devices first. Most SCSI peripheral devices must be running before the computer recognizes their existence.

Once the board is installed and all the peripherals are running, users will begin to really appreciate the power of a computer and how it can make their work more effective.

For more information on products mentioned in this article ...

* Adaptec, Inc. 691 South Milpitas Boulevard Milpitas, California 95035 Telephone: (408) 945-8600 * Future Domain 2801 McGraw Avenue Irvine, California 92714 Telephone: (800) 879-7599 * Ultrastor Corp. 13766 Alton Parkway Suite 144 Irvine, California 92718 Telephone: (714) 581-4100


* WHEN ADDING MULTIPLE peripherals to a computer, it's wise to use a SCSI (pronounced "scuzzy") board. It's the best way to avoid conflicts between the various peripherals.

* WHILE SOME COMPUTER makers are claiming their machines are plug-and-play, in reality there's still a gap between advertised claims and experience.

* A PROPERLY INSTALLED SCSI allows the addition of as many as seven peripherals to a computer.

* SCSI INSTALLATION is generally not a do-it-yourself job. It's best to turn to an experienced technician. If new equipment is being purchased, one should insist the peripherals be installed by the factory or the dealer and tested fully before delivery.

JAMES E. HUNTON, CPA, PhD, is an assistant professor at Virginia Commonwealth University, Richmond, Virginia. This year he was awarded the Lawler Award for the best article in the Journal of Accountancy in 1993.
COPYRIGHT 1994 American Institute of CPA's
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1994, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Title Annotation:small computer systems interface
Author:Hunton, James E.
Publication:Journal of Accountancy
Date:Dec 1, 1994
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Next Article:The case for non-CPA ownership: a roundup of practitioners' opinions on why change is needed.

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