Minicomputers: What is the choice?;

              MINICOMPUTERS: WHAT IS THE CHOICE?
by CHARLES L. BIGGS/Director, Management Services, Cleveland
and EVAN G. BIRKS/P.S. Ross & Partners, Toronto
What is the most cost-effective approach to data processing?
Many business managers find there is no clear-cut answer to
this question. The variety of equipment available to match
their data processing and communications needs, and its
continually improving price/performance ratios, have
made the options available to them almost infinite.
As a result, some basic management questions about
computers are back on the drawing board. Should we have
a large computer or several small computers? Should we
have centralized computers or decentralized computers?
The most recent and aggressive sales barrage has come
from minicomputer advocates, who assert that their
systems will:
• Offer twice the capacity at prices significantly less than
those of large systems;
• Provide the level of service needed by a smaller user,
when the data processing department is too busy with its
big systems;
• Offer on-site services to user departments who must
meet tight work schedules;
• Do the job at half the price charged by the corporate
service bureau;
• Increase efficiency by distributing the processing
throughout the data communications network.
What Is a Minicomputer?
The typical minicomputer is defined technically as a digital
processor with integrated semiconductor circuits, a 16-bit
word length, 4,096 to 32,768 words of magnetic core or
semiconductor storage, and fast memory cycle times of 0.8
to 1.5 microseconds; other word lengths, sizes, and speeds
also are available. The minicomputer is small in size and
usually weighs less than 50 lbs. It utilizes standard 115 volt
power, and reportedly needs no special environment.
While it is difficult to get precise agreement on the
definition of a minicomputer, it is generally agreed that it is
a computer whose processor,or"main frame," is available
at a purchase price ranging from $10,000to $30,000, and that
it provides index registers, multi-level indirect addressing,
and flexible input/output capabilities which may be
enhanced by one or more direct memory access channels.
Perhaps of greatest significance is its modularity, which
allows its assembly in an infinite variety of configurations.
A good deal of the debate over defining a minicomputer
is prompted by the overlapping characteristics of minicom­puters,
microcomputers, and midicomputers. (The accom­panying
table shows some characteristics of the processors
of these three types of computers—see page 15.)
The major weaknesses of minicomputers occur in the
areas of (1) hardware limitations, (2) software difficulties,
and (3) lack of vendor support. Most of the hardware
limitations can be resolved with such extra cost options as:
additional main storage, parity checking, storage protec­tion,
hardware multiply/divide instruction, a real-time
clock, power-failure protection, and direct memory access
channels.
The software difficulties relate to a lack of sophisticated,
generalized routines (from disk file access modules to
utilities to programming aids), the additional programming
required due to the minicomputers' short word lengths,
their sometimes limited storage capacity, and the single-purpose
orientation of their operating systems. This may
result in a relatively high cost for program development.
Underlying the lack of vendor support is the fact that the
cost of providing the type of support associated with larger
systems may be more today than the cost of the computer
hardware itself. Minicomputer manufacturers therefore
have directed their primary sales efforts toward original
equipment customers, including programming firms and
contract systems houses, treating them essentially as
wholesalers or branch offices.
The History of the Minicomputer
The minicomputer industry, which is just over 15 years old,
has grown rapidly since the mid 1960s. Total computer sales
currently exceed $14 billion annually, and the U.S.
Department of Commerce estimates that sales by the 70
minicomputer manufacturers are approximately 10 percent
of this market.
Behind the growth in the minicomputer industry are a
number of fundamental factors:
—Technological innovations in LSI (large-scale integrated)
circuits, which have resulted in dramatic price/perfor­mance
improvements;
—Specialized software products, which are uniquely suited
to minicomputer applications;
—Very competitive pricing among minicomputer vendors;
—An increasing emphasis on distributed processing, a
subject discussed below.
Minicomputer manufacturers deal with three major
markets. The first is original equipment manufacturers. A
high proportion of minicomputers' sales are being made
for incorporation into OEM products, such as machine
tools, process control units, or data entry devices. This is an
extremely competitive market where the specifications call
for acceptable performance at minimum cost. It also is a
very volatile market and was responsible for most of the
minicomputer growth during the industry's first decade.
The second market, which has emerged in the 1970s, is
comprised of sophisticated end-users of minicomputers.
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