Plugging in Computer Peripherals: With a SCSI, Many Devices Can Be Run off the Computer without a Hitch

Article excerpt

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. …