There has been plenty of talk recently about the demise of DOS as an operating system and about the 486 as a PC. In reality, both of these non-cutting edge products probably will be around until the turn of the century, and perhaps beyond, for applications such as word processing, spreadsheets, and other office applications.
DOS-based programs are still desirable for a number of reasons. First, DOS uses very little system memory. Second, DOS allows programs to "talk" directly to graphics adapters and other peripherals, gaining access to their maximum processing speed. Finally, and perhaps most important, DOS-based software remains relatively inexpensive compared with applications written for Windows and other platforms.
Systems with 486-class processors run DOS-based software packages extremely well, because these programs were written specifically for 32-bit operation in a DOS environment. Basically, the programs take over the machine: they do not have to deal with GUI overhead'' (the extra processor cycles that these operating systems use to create the graphical interface), so they can focus on speed. The performance of DOS-based programs will accelerate even further on systems with superfast EIDE hard-disk drives, which give the software direct access to data-transfer speeds of 16+ MB per second to and from disks.
The best statistical evidence that there is still broad commitment to the 486 was summarized in an unpublished study by Answers Research, Inc., distributed in December, 1995. The polling firm contacted 182 major PC dealers in October, 1995, to inquire about sales to businesses and institutions. During the third quarter of 1995 the mix of sales was 59 percent Pentium, 36 percent 486, and 5 percent Mac.
The upshot is that while GUI-based clients which access an automated library system and a number of other electronic information sources should be mounted on Pentium machines with Windows95, Windows NT, etc.; machines used for office applications can continue to be DOS-based 486s. This may mean juggling PCs within a library, but it doesn't mean discarding the older machines.
