Information Technology Reference
In-Depth Information
The first integrated circuits offering "small scale integration" - SSI - employed only a
few transistors (numbering in the tens) on each chip. These were used in the Minuteman
Missile and Apollo projects, both of which demanded very lightweight onboard computers
for inertial guidance systems. In turn, the late sixties saw "medium scale integration" - MSI
- devices which contained hundreds of transistors on each chip. Then, in the mid 1970s,
there came "large scale integration" - LSI - tens of thousands of transistors on each chip.
Various integrated circuits (such as 1K-bit RAMs, calculator chips, and the first micro-
processors) which began to be manufactured in moderate quantities in the early 1970s, had
under 4000 transistors. True LSI circuits, approaching 10000 transistors, began to be pro-
duced around 1974 for computer main memories and second-generation microprocessors.
Not until the early 1980s would the industry become capable of "very large scale integra-
tion" - VLSI. These circuits offered hundreds of thousands of transistors at the time, and
today can contain several billion transistors. By 1970, a number of semiconductor compan-
ies (not the least INTEL, founded by Robert Noyce, Gordon Moore and Andy Grove) were
in line to supply a reliable flow of economically-priced MSIs.
IBM's System/370, launched (as has been noted) in 1970, replaced the 360's solid logic
technology circuits with ICs. However, the rise of the IC influenced the minicomputer mar-
ketplace far more than it did the mainframe marketplace, in the latter of which IBM was
destined to remain dominant.
Up and coming tech entrepreneurs saw opportunities in the minicomputer marketplace
that they did not see in the mainframe universe. Where IBM's domination of mainframes
seemed unassailable, DEC's domination in the mini marketplace appeared considerably
less so. DEC was not perceived as an overpowering monopoly, a 300-pound gorilla. Per
Ceruzzi: "DEC did not dominate in minicomputers in the same way IBM dominated main-
frames. ... DEC's competitors did not feel they had to answer every product announcement,
or offer software-compatible products. Technical innovation, at low cost and in a compact
package, mattered more."
The lowering costs of chips and other aspects of manufacture led to the founding of
hundreds of DEC competitors, either as new firms or as subsidiaries of older companies.
While venture capitalists were uniformly unwilling to fund ventures designed to compete
with the monolith IBM, they were quite open to firms wanting to explore and exploit the
growing, open and increasingly-profitable market in minicomputing.
Still, DEC remained a formidable force. The firm's PDP-11 machine, launched in Janu-
ary of 1970, represented a complete rethinking of the traditional PDP architecture. The
machine's greatest innovation was a 56-line "Unibus" uniformly connecting just about all
the major units (memory, I/O devices) of the machine. This innovation made it relatively
simple for customers to configure specialized apps, making the machine easily and inex-
pensively adaptable for a broad range of purposes. To this day, the bus architecture remains
central to all computer design.
