He stood in my doorway, looking forlorn. He coughed.
"Yes?" I asked, giving him the opening he needed. He
moved closer.
"Mr. Slothower?"
I wish he wouldn't do that. It makes me feel old. Never mind the
fact that I am probably older than his father. I like to pretend
I am still just one of the gang.
"Yes Ryan?"
"What would be a good PC to buy?" he asked, looking
me square in the eye.
From anyone else this is an innocuous question. But Ryan? Our
Macintosh guru? Our champion of Apple? Has the world gone mad?
"Well, gee Ryan, why don't you sit down and let's talk about
it."
He ambled into the room, took one of my rickety director chairs,
and looked at me, his face a model of innocence. This is not a hard
task for Ryan, who, at nineteen, has the angelic look (and life
style) of the new generation of computer fanatics. He reads science
fiction (don't condemn him for that, I read it to), attends science
fiction conventions (a more questionable activity) and is constantly
loading cute little programs on our three Macs that no one understands.
"A PC, Ryan?" I asked. "What has prompted this change
of heart? Perhaps Hell has frozen over?"
"No, Mr. Slothower, I . . . "
"Don't DO that, it makes my arthritis act up."
"Do what Mr. Slothower?"
"Never mind". I resign myself to feeling my age.
He launches into explanation.
"I've got a Mac Plus at home, and it's time to move up. I've
been looking at the new pricing on Macs and for what I want to do,
they cost more than I want to pay. Besides, I think I should probably
learn DOS (the operating system for the IBM-compatible world)."
"A good idea," I commented.
"So," he continued, "what is a PS/2?"
"An idea whose time has not yet come."
"So I shouldn't get one?"
"I would consider the alternatives," I consoled.
"Which are?"
"Read my column" I said.
The choices today can be confusing. In the DOS/IBM-compatible
world there are three basic architectures, and within these three
divisions a wide range of choices for power, speed and quality of
display.
The Basic IBM-Compatible Food Groups
When IBM revolutionized the infant personal computer industry it
introduced what came to be known as the IBM/IBM-compatible PCs.
One architecture, one name. No big problem. (Architecture is the
word used to describe the basic physically structure and operation
of the computer).
Then the clones appeared and in a fit of pique IBM decided that
they wanted their very own computer that no one else could copy
and, in 1987, introduced the PS/2.
Now we had two architectures: Let the confusion begin.
PS/2 was designed to provide more power to the user, and let the
computer do things that were not possible under the old design.
To date this has not made a great deal of difference to most users,
who continue to buy the older style PC.
However, the clone vendors saw the PS\2 as a threat and decided
they needed to offer an alternative and, after much haggling, came
up with yet another architecture which EXTENDED the capabilities
of the original systems and was backwardly compatible.
Today's buyer of an DOS/IBM-compatible has three choices:
ISA: Industry Standard Architecture
This is the basic architecture introduced and is still by far
the most common. The name was not invented until after the introduction
of the PS/2. It is available with XT, AT, 386 and 486 processors
and unless otherwise noted any DOS computer is ISA.
Advantages: By far the cheapest. Has the most choices for vendors,
and add on hardware (modems, drives, monitors, fax boards, etc.).
Disadvantages: Does not have some of the high power capability
of other systems. However, this matters most when dealing
with things like very high-speed multiple drives, scientific
applications, and other esoteric functions. If you have to
read this column to understand the differences then you should
probably go with ISA.
PS/2
Introduced in 1987 the IBM PS/2 has never really taken off.
The PS/2 is fully software compatible with everything else but offered
greater growth capacity and, eventually some powerful functions
like Bus Mastering (letting add-on boards take control of the main
data paths - if you don't understand this call Sheppard Labs, I
am sure they would enjoy explaining it to you). The new bus is called
the MicroChannel (except the 30/286).
Advantages: greater growth potential, theoretical performance
improvements, easier process of installing add-on boards. In addition
the PS/2 contains a built in VGA monitor controller (normally an
add-on in other systems).
Disadvantages: Expensive; very few vendors of compatible add-on
boards, which tend to be more expensive (Example: ISA 2400 internal
modem = $139.95, PS/2 2400 internal modem = $223.22); many of the
advantages suggested by IBM have yet to be realized. In addition,
users tend to buy new machines when they need more power, rather
than upgrading existing computers.
EISA: Extended Industry Standard Architecture
This was the clone industry's answer to the PS/2. It took the
main features of ISA and expanded them without losing compatibility
with older equipment. This means that modems, serial boards, drive
controllers and other older equipment can still be used. In addition,
some of the features of PS/2 were incorporated, like a wider bus
(more data moving at the same time) and, often, built-in monitor
controllers. Advantages: Middle price range; designed to offer the
power advantages of PS/2's at lower cost. Again, like the PS/2,
this is a high grade machine whose advantages may not touch most
users.
Disadvantages: More expensive than ISA, not totally standardized.
In some cases there may be only one vendor for specific add-on boards,
a situation which limits price competition.
"Well Ryan, what do you think?" I asked.
"On reflection", he said "the Mac LS looks pretty
good."
