PC Magazine -- December 17, 1996
This year marks the 25th anniversary of the commercial launch of the first true microprocessor, built by Intel engineers for an early electronic adding machine. Since then, we've seen steady and astronomical increases in microprocessor power and complexity. Here are some of the key moments in that 25-year history
Designed by Intel's Ted Hoff, Stan
Mazor, and Federico Faggin, along with Busicom's Masatoshi Shima, the Intel
4004 was the world's first general-purpose microprocessor. It consisted of
only 2,300 transistors in a 4-bit architecture, supported 45 instructions,
and ran at under 1 MHz. Laughably underpowered by today's standards, this
seminal chip literally changed the world.
The 8008, which had 3,500 transistors,
was the first 8-bit microprocessor. Eight-bit data allowed the 8008 to
manage alphanumeric data.
Intel introduced the 8080, a 2-MHz,
6,000-transistor microprocessor with 16-bit addressing that was eventually
to become the heart of the MITS Altair, the first microcomputer. A small
soft ware start-up, Micro Soft, was launched by Bill Gates and Paul Allen,
who wrote a BASIC interpreter for the Altair system as the company's first
The Motorola 6800, with 4,000
transistors, was designed by Chuck Peddle and Charlie Melear. It was mainly
used in automotive controls and small-business machines.
The Z80, designed by Faggin and Shima,
was seen as an improved version of the 8080. An 8-bit, 8,500-transistor
processor with 16-bit addressing that ran at 2.5 MHz, it hosted CP/M, the
first standard microprocessor operating system. The Z80 was the choice of
many pioneer system vendors including Osborne and Kaypro, and, in many
ways, brought PCs into business.
MOS Technologies introduces the 6502,
an 8-bit processor with very few registers and a 16-bit address bus,
developed by Peddle and colleagues. It sold for around $25 in the
mid-seventies, a price that appealed to Steve Wozniak for his Apple II
design. The 6502 launched the notion of personal computing in the public
imagination and was used in several other popular PCs, including the
Commodore PET, the Commodore 64, and the early Atari machines. Essentially
an enhanced Motorola 6800, it made graphics effects easier to program and
faster to execute, setting the computer gaming phenomenon in motion.
Approximately 9,000 transistors
The 8086 was a 16-bit chip with 29,000
transistors. It introduced the x86 instruction set that's still
present on x86-compatible chips today. Its segmented memory
addressing was quite ingenious, but it ultimately proved to be a millstone
that hung around the industry's neck for years.
Intel's 8088 was based on the earlier
8086. Like the earlier processor, the 8088 had a 16-bit internal
architecture, but it communicated with other components through an 8-bit
bus. IBM chose this cost-saving design for its first PC, the direct
ancestor of today's dominant personal computing platform. This was the chip
that would launch DOS, Lotus 1-2-3, and other groundbreaking software.
Motorola's 68000, with a new 32-bit
instruction set, was the platform for some of the early Unix systems. More
important, Apple chose it to implement the Lisa and later the Macintosh,
the system that featured the first commercially successful graphical user
Intel introduces its 286, the first x86
processor to support general protection and virtual memory. Used in the IBM
PC AT (whose 16-bit AT extension-bus design is still in use for slower
peripherals), the 286 ran at speeds of 8 to 12 MHz and delivered up to six
times the power of the 8086. The 286 could support up to 16MB of physical
The 386 was a pivotal chip that enabled
the transition to the modern era of personal computing. This 32-bit
design--with over a quarter of a million transistors and a 4GB address
space --was the first mainstream Intel chip to support linear addressing.
It was on this platform that graphical operating environments, such as MS
Windows and OS/2, began to seem workable. And it was with this chip that we
stopped thinking about IBM compatibility and started to focus on the
processor and operating system as the true platform.
MIPS ships its R2000, the first
commercial RISC microprocessor.
Sun introduces its first SPARC
microprocessor. This chip and its offspring defined several generations of
Intel ships its 486 processor, an
enhanced 386 design. Its more than 1 million transistors included a
built-in floating-point unit and 8K of internal RAM cache.
1.2 million transistors
Intel ships its Pentium, incorporating
a superscalar architecture whose dual-pipeline design could execute two
instructions at once. With dual- integer units and a single FPU, and
running at relatively high speeds, this chip (with its 3.1 million
transistors) forms the basis for today's mass-market computer industry. It
became the platform of choice for running Windows 95 and a host of PC
applications, while at the same time bringingx86-based servers into
direct competition with non-Intel machines.
3.1 million transistors
IBM and Motorola's PowerPC 601 brought
RISC technology to mass-market computers. It was one of the first
microprocessors to implement out-of-order execution of instructions. This
processor and its suc- cessors have been adopted by Apple for its Power
2.8 million transistors
The Pentium Pro is the most powerful
Intel processor in production today. It uses an aggressively superscalar
design that can execute up to three instructions simultaneously. The core
CPU, with 5.5 million transistors, is paired with a second chip containing
a Level 2 cache. Mounted in a single package, these dies are connected by
an ultra-high-speed bus. The Pentium Pro debuted at the high end of the
Intel-based server market but has since found its way into high-end and
even mainstream workstations.
5.5 million transistors
|Copyright (c) 1997 Ziff-Davis Inc.|