TCMHC: Timeline of Computer History

Williams tube		1947 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		1947 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		1953 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.


Regency radio		1954 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 Teal's 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		1955 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.


IBM 305 RAMAC		1956 The era of magnetic disk storage dawned with IBM's shipment of a 305 RAMAC to Zellerbach Paper in San Francisco. The IBM 350 disk file served as the storage component for the Random Access Method of Accounting and Control. It consisted of 50 magnetically coated metal platters with 5 million bytes of data. The platters, stacked one on top of the other, rotated with a common drive shaft.


Kilby integrated circuit		1958 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.


Silicon integrated circuit		1959 Robert Noyce's practical integrated circuit, invented at Fairchild Camera and Instrument Corp., allowed printing of conducting channels directly on the silicon surface.


RTL integrated circuit		1961 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.


		1962 Virtual memory emerged from a team under the direction of Tom Kilburn at the University of Manchester. Virtual memory permitted a computer to use its storage capacity to run outside software and switch rapidly among multiple programs.


Fairchild NPN transistor		1962 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		1967 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.


		1967 Using integrated circuits, Medtronics constructed the first internal pacemaker.


Intel 4004		1971 The first advertisement for a microprocessor, the Intel 4004, appeared in Electronic News. Federico Faggin, Ted Hoff, and others at Intel designed the 4004 while building a custom chip for Busicom, a Japanese calculator maker. The 4004 had 2,250 transistors, handling data in four-bit chunks, and could perform 60,000 operations per second.


		1971 An IBM team, originally led by Alan Shugart, invented the 8-inch floppy diskette. It was initially designed for use in loading microcode into the controller for the "Merlin" (IBM 3330) disk pack file. It quickly won widespread acceptance as a program and data-storage medium. Unlike hard drives, a user could easily transfer a floppy in its protective jacket from one drive to another.


Intel 8008		1972 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		1974 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.


5 1/4-inch floppy		1978 The 5 1/4" flexible disk drive and diskette were introduced by Shugart Associates in 1976. This was the result of a request by Wang Laboratories to produce a disk drive small enough to use with a desktop computer, since 8" floppy drives were considered to be too large for that purpose. By 1978, more than 10 manufacturers were producing 5 1/4" floppy drives.


Motorola 68000		1979 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		1979 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.


		1980 Seagate Technology created the first hard disk drive for microcomputers. The disk held 5 megabytes of data, about fifty times as much as a standard floppy disk, and fit in the space of a floppy disk drive. The hard disk drive itself is a rigid metallic platter coated on both sides with a thin layer of magnetic material that stores digital data. Along with the benefit of increased storage, hard disks have one major drawback: Permanent installation into the computer decreases their portability. Seagate Technology grew out of a 1979 conversation between Alan Shugart and Finis Conner, who had worked together at IBM. The two men decided to found the company after developing the idea of scaling down a hard disk drive to the same size as the then-standard 5 1/4-inch floppies. Upon releasing its first product, Seagate quickly drew such big-name customers as Apple Computer and IBM. Within a few years, it had sold 4 million units.


		1980 The first optical data storage disk had 60 times the capacity of a 5 1/4-inch floppy disk. Developed by Philips, the disk stored data as indelible marks burned by a laser that could not be overwritten -- making it useful primarily for storing large quantities of information that would never need revision. Two years later, Philips created an erasable optical disk using special material, a laser, and magnetism to combine the capacity of an optical disk with the convenience of an option to erase and rewrite. A laser beam recording a spiral of information on a photosensitive surface produces an optical disk. Two layers of clear plastic protect the metal surface on which the information is recorded. On erasable optical disks, also called magneto-optic disks, the entire metal surface is magnetized in one direction. Instead of recording information permanently by melting holes in the metal, the laser heats a spot to just below its melting point so a magnet can reverse the direction of the metal's magnetic flux. Reheating the disk to restore its original orientation erases it.


		1981 Sony introduced and shipped the first 3 1/2" floppy drives and diskettes in 1981. The first signficant company to adopt the 3 1/2" floppy for general use was Hewlett-Packard in 1982, an event which was critical in establishing momentum for the 3 1/2" format and which helped it prevail over the other contenders for the microfloppy standard, including 3 1/4", 3", and 3.9" formats.


		1985 Able to hold 550 megabytes of prerecorded data, the new CD-ROMs grew out of regular CDs on which music is recorded. Their capacity is great enough that they rarely fill up, even with information that would take up thousands of pages of paper. The first general-interest CD-ROM product released after Philips and Sony announced the CD-ROM in 1984 was "Grolier's Electronic Encyclopedia," which came out in 1985. The 9 million words in the encyclopedia only took up 12 percent of the available space. The same year, computer and electronics companies worked together to set a standard for the disks so any computer would be able to access the information.


		1986 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		1986 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		1987 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.


		1988 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		1989 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		1989 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.

Timeline | Collections | Exhibits | Research | Events | Contribute | About The History Center | Site Search
Copyright | Privacy | Feedback