While the 1960s were the decade of the mainframe, the 1970s gave rise to Ethernet, which today is by far the most popular LAN technology. Ethernet was born in 1973 in Xerox's research lab in Palo Alto, California.
(An earlier experimental network called ALOHAnet was developed in 1970 at the University of Hawaii.)
The original Xerox networking system was known as X-wire and worked at 2.94 Mbps. X-wire was experimental and was not used commercially, although a number of Xerox Alto workstations for word processing were networked together in the White House using X-wire during the Carter administration.
In 1979, Digital Equipment Corporation (DEC), Intel, and Xerox formed the DIX consortium and developed the specification for standard 10-Mbps Ethernet, or thicknet, which was published in 1980. This standard was revised and additional features were added in the following decade.
The conversion of the backbone of the Bell telephone system to digital circuitry continued during the 1970s and included the deployment in 1974 of the first digital data service (DDS) circuits (then called the Dataphone Digital Service). DDS formed the basis of the later deployment of ISDN and T1 lines to customer premises. AT&T installed its first digital switch in 1976.
In wide area networking, a new telecommunications service called X.25 was deployed toward the end of the decade. This system was packet-switched, in contrast to the circuit-switched PSTN, and later evolved into public X.25 networks such as GTE's Telenet Public Packet Distribution Network (PDN), which later became Sprintnet. X.25 was widely deployed in Europe, where it still maintains a large installed base.
In 1970, the Federal Communications Commission (FCC) announced the regulation of the fledgling cable television industry. (Cable TV remained primarily a broadcast technology for delivering entertainment to residential homes until the mid-1990s, when technologies began to be developed to enable it to carry broadband Internet access services to residential subscribers.)
Despite all the technological advances, however, telecommunications services in the 1970s remained unintegrated, with voice, data, and entertainment carried on different media. Voice was carried by telephone, which was still analog at the customer premises; entertainment was broadcast using radio and television technologies; and data was usually carried over RS-232 or Binary Synchronous Communication (BSC) serial connections between dumb terminals and mainframes (or, for remote terminals, long-haul modem connections over analog telephone lines).
The 1970s were also notable for the birth of ARPANET, the precursor to the Internet, which was first deployed in 1969 and grew throughout the decade as additional hosts were added at various universities and government institutions.
By 1971, the network had 19 nodes, mostly consisting of a mix of PDP-8, PDP-11, IBM S/360, DEC-10, Honeywell, and other mainframe and minicomputer systems linked together.
The initial design of ARPANET called for a maximum of 265 nodes, which seemed like a distant target in the early 1970s. The initial protocol used on this network was NCP, but it was replaced in 1982 by the more powerful TCP/IP protocol suite. In 1975, the administration of ARPANET came under the authority of the Defense Communications Agency.
ARPANET protocols and technologies continued to evolve using the informal RFC process. In 1972, the Telnet protocol was defined in RFC 318, followed by FTP in 1973 (RFC 454). ARPANET became an international network in 1973 when nodes were added at the University College of London in the United Kingdom and at the Royal Radar Establishment in Norway. ARPANET even established an experimental wireless packet-switching radio service in 1977, which two years later became the Packet Radio Network (PRNET).
Meanwhile, in 1974 the first specification for the Transmission Control Protocol (TCP) was published. Progress on the TCP/IP protocols continued through several iterations until the basic TCP/IP architecture was formalized in 1978, but it wasn't until 1983 that ARPANET started using TCP/IP as its primary networking protocol instead of NCP.
1977 saw the development of UNIX to UNIX Copy (UUCP), a protocol and tool for sending messages and transferring files on UNIX-based networks. An early version of the USENET news system using UUCP was developed in 1979. (NNTP came much later, in 1987.)
In 1979, the first commercial cellular phone system began operation in Japan. This system was analog in nature, worked in the 800-MHz and 900-MHz frequency bands, and was based on a concept developed in 1947 at Bell Laboratories.
An important standard to emerge in the 1970s was the public-key cryptography scheme developed in 1976 by Whitfield Diffie and Martin Hellman. This scheme underlies the Secure Sockets Layer (SSL) protocol developed by Netscape Communications, which is now the predominant scheme for ensuring privacy and integrity of financial and other transactions over the World Wide Web (WWW). Without this scheme, popular e-business sites such as Amazon.com would have a hard time attracting customers.
In miscellaneous developments in the 1970s, IBM researchers invented the relational database in 1970, a set of conceptual technologies that has become the foundation of today's distributed application environments. In 1971, IBM demonstrated the first speech recognition technologies, which have since led to automated call handling systems in customer service centers. IBM developed the concept of the virtual machine in 1972 and created the first sealed disk drive (the Winchester) in 1973. IBM introduced SNA for networking in its mainframe computing environment in 1974. In 1971, Intel released its first microprocessor, a 4-bit processor called the 4004 that ran at a clock speed of 108 kHz. The online service CompuServe was launched in 1979.
The first personal computer, the Altair, went on the market as a kit in 1975. The Altair was based on the Intel 8080, an 8-bit processor, and came with 256 bytes of memory, toggle switches, and LED lights. While the Altair was basically for hobbyists, the Apple II from Apple Computer, which was introduced in 1977, was much more. A typical Apple II system, which was based on the Motorola 6502 8-bit processor, had 4 KB of RAM, a keyboard, a motherboard with expansion slots, built-in BASIC in ROM, and color graphics. The Apple II quickly became the standard desktop system in schools and other educational institutions. A physics classroom I taught in had one all the way into the early 1990s (limited budget!). However, it wasn't until the introduction of the IBM Personal Computer (PC) in 1981 that the full potential of personal computers began to be realized, especially in businesses.
In 1975, Bill Gates and Paul Allen licensed their BASIC programming language to MITS, the manufacturer of the Altair. BASIC was the first computer language program specifically written for a personal computer. Gates and Allen coined the name "Micro-soft" for their business partnership, and they officially registered it as a trademark the following year. Microsoft went on to license BASIC to other personal computing platforms such as the Commodore PET and the TRS-80.
Computer networks for everyone. Standardization of Ethernet. The coaxial cable reign.