Timeline of Computer History

Williams tube
The Williams tube won the race for a practical random-access memory. Sir Frederick Williams of Manchester University modified a cathode-ray tube to paint dots and dashes of phosphorescent electrical charge on the screen, representing binary ones and zeros. Vacuum tube machines, such as the IBM 701, used the Williams tube as primary memory.
Point-contact transistor
On December 23, William Shockley, Walter Brattain, and John Bardeen successfully tested this point-contact transistor, setting off the semiconductor revolution. Improved models of the transistor, developed at AT&T Bell Laboratories, supplanted vacuum tubes used on computers at the time.
Core memory
At MIT, Jay Forrester installed magnetic core memory on the Whirlwind computer. Core memory made computers more reliable, faster, and easier to make. Such a system of storage remained popular until the development of semiconductors in the 1970s.
First production silicon junction transistors
A silicon-based junction transistor, perfected by Gordon Teal of Texas Instruments Inc., brought the price of this component down to $2.50. A Texas Instruments news release from May 10, 1954, read, "Electronic "brains" approaching the human brain in scope and reliability came much closer to reality today with the announcement by Texas Instruments Incorporated of the first commercial production of silicon transistors kernel-sized substitutes for vacuum tubes."

The company became a household name when the first transistor radio incorporated Tealīs invention. The radio, sold by Regency Electronics for $50, launched the world into a global village of instant news and pop music.
Felker and Harris program TRADIC
Felker and Harris program TRADIC, AT&T Bell Laboratories announced the first fully transistorized computer, TRADIC. It contained nearly 800 transistors instead of vacuum tubes. Transistors — completely cold, highly efficient amplifying devices invented at Bell Labs — enabled the machine to operate on fewer than 100 watts, or one-twentieth the power required by comparable vacuum tube computers.

In this photograph, J. H. Felker (left) gives instructions to the TRADIC computer by means of a plug-in unit while J. R. Harris places numbers into the machine by flipping simple switches. The computer occupied only 3 cubic feet.
Kilby integrated circuit
Jack Kilby created the first integrated circuit at Texas Instruments to prove that resistors and capacitors could exist on the same piece of semiconductor material. His circuit consisted of a sliver of germanium with five components linked by wires.
First Planar transistor
Jean Hoerni's Planar process, invented at Fairchild Camera and Instrument Corp., protects transistor junctions with a layer of oxide. This improves reliability and, by allowing printing of conducting channels directly on the silicon surface, enabled Robert Noyce's invention of the monolithic integrated circuit. 
RTL integrated circuit
Fairchild Camera and Instrument Corp. invented the resistor-transistor logic (RTL) product, a set/reset flip-flop and the first integrated circuit available as a monolithic chip.
Fairchild NPN transistor
Fairchild Camera and Instrument Corp. produced the first widely accepted epitaxial gold-doped NPN transistor. The NPN transistor served as the industry workhouse for discrete logic.
MOS semiconductor
Fairchild Camera and Instrument Corp. built the first standard metal oxide semiconductor product for data processing applications, an eight-bit arithmetic unit and accumulator. In a MOS chip, engineers treat the semiconductor material to produce either of two varieties of transistors, called n-type and p-type.
   Using integrated circuits, Medtronics constructed the first internal pacemaker.
Intel 4004
The first advertisement for a microprocessor, the Intel 4004, appeared in Electronic News. Developed for Busicom, a Japanese calculator maker, the 4004 had 2250 transistors and could perform up to 90,000 operations per second in four-bit chunks. Federico Faggin led the design and Ted Hoff led the architecture.
Intel 8008
Intel´s 8008 microprocessor made its debut. A vast improvement over its predecessor, the 4004, its eight-bit word afforded 256 unique arrangements of ones and zeros. For the first time, a microprocessor could handle both uppercase and lowercase letters, all 10 numerals, punctuation marks, and a host of other symbols.
Zilog Z-80
Intel and Zilog introduced new microprocessors. Five times faster than its predecessor, the 8008, the Intel 8080 could address four times as many bytes for a total of 64 kilobytes. The Zilog Z-80 could run any program written for the 8080 and included twice as many built-in machine instructions.
Motorola 68000
The Motorola 68000 microprocessor exhibited a processing speed far greater than its contemporaries. This high performance processor found its place in powerful work stations intended for graphics-intensive programs common in engineering.
Introduction to VLSI Systems
California Institute of Technology professor Carver Mead and Xerox Corp. computer scientist Lynn Conway wrote a manual of chip design, "Introduction to VLSI Systems." Demystifying the planning of very large scale integrated (VLSI) systems, the text expanded the ranks of engineers capable of creating such chips. The authors had observed that computer architects seldom participated in the specification of the standard integrated circuits with which they worked. The authors intended "Introduction to VLSI Systems" to fill a gap in the literature and introduce all electrical engineering and computer science students to integrated system architecture.
   David Miller of AT&T Bell Labs patented the optical transistor, a component central to digital optical computing. Called Self-ElectroOptic-Effect Device, or SEED, the transistor involved a light-sensitive switch built with layers of gallium arsenide and gallium aluminum arsenide. Beams of light triggered electronic events that caused the light either to be transmitted or absorbed, thus turning the switch on or off.

Within a decade, research on the optical transistor led to successful work on the first all-optical processor and the first general-purpose all-optical computer. Bell Labs researchers first demonstrated the processor there in 1990. A computer using the SEED also contained lasers, lenses, and fast light switches, but it still required programming by a separate, non-optical computer. In 1993, researchers at the University of Colorado unveiled the first all-optical computer capable of being programmed and of manipulating instructions internally.
Compaq beat IBM to the market when it announced the Deskpro 386, the first computer on the market to use Intel´s new 80386 chip, a 32-bit microprocessor with 275,000 transistors on each chip. At 4 million operations per second and 4 kilobytes of memory, the 80386 gave PCs as much speed and power as older mainframes and minicomputers.

The 386 chip brought with it the introduction of a 32-bit architecture, a significant improvement over the 16-bit architecture of previous microprocessors. It had two operating modes, one that mirrored the segmented memory of older x86 chips, allowing full backward compatibility, and one that took full advantage of its more advanced technology. The new chip made graphical operating environments for IBM PC and PC-compatible computers practical. The architecture that allowed Windows and IBM OS/2 has remained in subsequent chips.
Motorola 68030
Motorola unveiled the 68030 microprocessor. A step up from the 68020, it built on a 32-bit enhanced microprocessor with a central processing unit core, a data cache, an instruction cache, an enhanced bus controller, and a memory management unit in a single VLSI device — all operating at speeds of at least 20 MHz.
   Compaq and other PC-clone makers developed enhanced industry standard architecture — better than microchannel and retained compatibility with existing machines. EISA used a 32-bit bus, or a means by which two devices can communicate. The advanced data-handling features of the EISA made it an improvement over the 16-bit bus of industry standard architecture. IBM´s competitors developed the EISA as a way to avoid paying a fee to IBM for its MCA bus.
Intel 80486
Intel released the 80486 microprocessor and the i860 RISC/coprocessor chip, each of which contained more than 1 million transistors. The RISC microprocessor had a 32-bit integer arithmetic and logic unit (the part of the CPU that performs operations such as addition and subtraction), a 64-bit floating-point unit, and a clock rate of 33 MHz.

The 486 chips remained similar in structure to their predecessors, the 386 chips. What set the 486 apart was its optimized instruction set, with an on-chip unified instruction and data cache and an optional on-chip floating-point unit. Combined with an enhanced bus interface unit, the microprocessor doubled the performance of the 386 without increasing the clock rate.
Motorola 68040
Motorola announced the 68040 microprocessor, with about 1.2 million transistors. Due to technical difficulties, it didn´t ship until 1991, although promised in January 1990. A 32-bit, 25-MHz microprocessor, the 68040 integrated a floating-point unit and included instruction and data caches. Apple used the third generation of 68000 chips in Macintosh Quadra computers.
Intel Pentium Processor diagram
The Pentium microprocessor is released. The Pentium was the fifth generation of the ‘x86’ line of microprocessors from Intel, the basis for the IBM PC and its clones. The Pentium introduced several advances that made programs run faster such as the ability to execute several instructions at the same time and support for graphics and music.


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