- Intel designs the 4004 microprocessor. The name is derived from the approximate number of transistors that it replaced, and indirectly was a measure of its complexity, as it handled 4 bits of data at a time.
- Micro Instrumentations Telemetry Systems (MITS), started by Ed Roberts, begins to manufacture and sell calculators.
The Department of Defense’s Advanced Research Project Agency funds the creation of ARPANet, to make it possible for their various research facilities to communicate with each other from around the country. It begins with only three host computers, and eventually evolves to become what is now known as the Internet.
ARPA’s Network Working Group designs “telnet”, a protocol that allowed users to logon remotely to any computer on the ARPANet network.
- Steve Wozniak and his high-school friend Bill Hernandez build a computer out of parts rejected by local companies, ending up with a box with lights and switches (similar to the Altair 8800 that would not appear until 1975). They called it the “Cream Soda Computer”, since that was their drink of choice while they were building it. The first demonstration of the computer burned up the power supply.
- Wozniak and Steve Jobs start their first joint business venture, selling “blue boxes” (capable of making “free” long distance phone calls) at the Berkeley dorms.
- Intel begins to advertise the 4004 processor, beginning with the fall 1971 issue of Electronic News. Regis McKenna, whose agency would later be hired to advertise the Apple II computer, designs the promotion.
- Intel begins work on an 8-bit processor, the 8008.
- Paul Allen convinces Bill Gates to join him in writing a BASIC interpreter for this new 8008 processor. They design a machine to use it, and form their first business venture, a company called Traf-O-Data, to process traffic information using their small computer.
- Intel contracts with Gary Kildall, a professor at the Naval Postgraduate School in Pacific Grove, California, to write a computer language that would run on the Intel 4004 processor. Kildall choses to create PL/M, a version of a mainframe computer language called PL/I. In the process of writing this language, Kildall develops a simple operating system as a background for the interpreter and to control a paper-tape reader and writer. This operating system was the basis for what he later called CP/M (“Control Program/Monitor”).
- The U.S. government’s official name for ARPA (“Advanced Research Projects Agency”) is changed to DARPA (“Defense Advanced Research Projects Agency”), to stress the defense role the organization had played from its very inception. The name “ARPANet” is not changed, however.
Intel introduces the 8008 microprocessor, which runs at a speed of 200 kHz (or 0.2 MHz), and sells for $360.
First public demonstration of ARPANet at the International Conference on Computer Communication, held in Washington, DC.
- Steve Wozniak takes a summer job and joins Bill Hernandez at Hewlett-Packard in their calculator division.
- Wozniak starts up “Dial-A-Joke” from his apartment, telling Polish jokes in a thick accent. This phone line becomes one of the most frequently called numbers in the San Francisco Bay area.
- Xerox’s Palo Alto Research Center (PARC) develops the “Alto”, a breakthrough computer which used a pointing device called a “mouse”, a bit-mapped graphic screen, and icons to represent documents. Also, it had a 2.5 megabyte removable disk cartridge and the first implementation of Ethernet. It cost $15,000 just to build it, and only 1,200 were ever produced. This computer and the Xerox Star were the inspirations within a decade for the Lisa and the Macintosh.
- Kildall’s CP/M is modified to work with the Intel 8008 microprocessor, and to interface with a disk drive. It now stands for “Control Program for Microcomputers”.
The Micral computer is released in France. It is the first computer built around a microprocessor, the Intel 8008. Designed by François Gernelle, and sold by the French company R2E for $1,750, fully assembled, it did not have any impact in the U.S.
Radio Electronics magazine prints a construction article called “TV Typewriter” by Don Lancaster. This project allowed users to create a video terminal that worked with a standard television, and would allow them to connect to a mainframe computer — if they had one available. It could display 16 lines of 32 uppercase characters.
Motorola introduces the 6800 microprocessor.
Scelbi-8H microcomputer introduced.
Intel introduces the 8080 microprocessor, the successor to the 8008.
Steve Jobs begins work at Atari.
Vint Cerf and Bob Kahn publish a paper proposing the use of a transmission-control protocol (TCP) to make it possible to share information between different computer networks.
The July issue of Radio Electronics introduced the Mark-8, the first computer kit to build at home. It uses the Intel 8008 chip, which by this time was selling for only $120.
A group of eight engineers and marketers, including Bill Mensch and Chuck Peddle, leave Motorola to work for MOS Technology, at that time the world’s largest manufacturer of calculator chips. They begin to design a microprocessor for the company to sell.
Creative Computing starts publication.
The Altair 8800 appears on the cover of the January issue of Popular Electronics.
Bill Gates and Paul Allen begin writing the first dialect of BASIC that would run on a personal computer, the new Altair. Their development was done using an 8080 emulator running on a PDP-10 computer, and was based on DEC’s BASIC-PLUS.
Zilog, founded by former Intel employees, announces the Z-80 microprocessor. This chip functions just like an Intel 8080, but with some additional features.
First meeting of Homebrew Computer Club.
IMSAI Manufacturing of San Leandro, California, begins work on a clone of the Altair 8800.
Scelbi-8B (business) computer introduced.
Gates and Allen change the name of their company from Traf-O-Data to Micro-Soft.
Micro-Soft’s Altair BASIC is announced. It is shipped on paper tape. MITS makes it available in two forms: for $500 when purchased by itself, or $75 when purchased with an Altair, a cassette interface, or 8K of MITS memory. The entire Altair 8800 cost only $400!
Altair BASIC is finally available for sale, in 4K and 8K versions. It is called “version 2.0″, even though it is the first official BASIC that shipped.
Micro-Soft contracts with MITS for software development.
The government entity called the Defense Communications Agency (DCA), which in the 1960′s was uninterested in the concept of a packet-sending distributed network, agrees to take over control of ARPANET from DARPA.
First meeting of the Chicago Area Computer Hobbyist Exchange (CACHE) at at Northwestern University.
BYTE begins publication.
MOS Technology introduces the 6501 and 6502 microprocessors at Wescon, the annual West Coast electronics show. These were created by the group of engineers who had left Motorola and joined MOS Technology in 1974.
MITS announces the Altair 680b, a 6800-based cousin to the Altair 8800. It was not a big success for the company.
The IMSAI 8080 released, the first major competitor to the Altair 8800. It used larger, flat switches for front-panel data input than did the Altair 8800, which made it easier on fingers than the tiny switches on the Altair. With 4K RAM in the base unit, it was sold as a kit for $439, or assembled for $621 (the same price as the Altair).
Paul Terrell, a salesman who was a member of the Homebrew Computer Club, opens the BYTE Shop in Mountain View, California, and begins selling the Altair 8800.
- First meeting of the Boston Computer Society.
- Processor Technology introduces the Sol ($995 in kit form).
- Cromenco sells the TV Dazzler ($215), a color graphics card for the Altair.
- Shugart introduces its 5.25 inch floppy disk drive for $390.
- Dr. Dobb’s Journal Of Computer Calisthenics And Orthodontia begins publication. Its first three issues reprint the source and object code listing for “Tiny BASIC”, written by Dennis Albrecht as a free and simple alternative to Microsoft’s much more expensive BASIC.
- The first version of Adventure for microcomputers is translated by Crowther and Wood from mainframe versions.
The first World Altair Computer Conference is hosted by MITS in Albuquerque, New Mexico.
Wozniak and Jobs form the Apple Computer Company on April Fool’s Day.
Wozniak’s 6502 computer, later known as the Apple Computer or the Apple-1, is introduced to the Homebrew Computer Club in Palo Alto, California.
The Apple-1 is delivered for sale at at Paul Terrell’s BYTE Shop ($666.66). It required the addition of a power supply, monitor and keyboard.
Zilog’s Z-80 microprocessor, running at 2.5 MHz, is released.
Microsoft begins working on versions of its BASIC for microprocessors other than the Intel 8080. Marc McDonald, Microsoft’s first employee, writes a 6502 BASIC after modifying a Motorola 6800 simulator to work with the 6502 (which was similar). However, there were as yet no customers for a 6502 BASIC.
Processor Technology introduces the Sol, an Altair-compatable 8080 computer.
Interface Age begins publication.
PC’76, a microcomputer conference, is held in Atlantic City, New Jersey. Steve Jobs and Steve Wozniak attend and demonstrate the Apple-1 and its new cassette interface. Wozniak completes his Apple BASIC interpreter (the precursor of Integer BASIC) in the hotel room the night prior to the conference, using the hotel TV as a monitor.
Wozniak completes prototype of the Apple II. Chris Espinosa begins working on games and demonstration software for it.
Wozniak is persuaded to leave Hewlett-Packard and work at Apple full-time.
Commodore International buys MOS Technology, the company that created the 6502 processor.
ComputerLand opens its first retail store in Hayward, California, selling IMSAI, Processor Technology, Polymorphic, Southwest Tech, and Cromemco.
Using an Altair 8800, Michael Shrayer creates Electric Pencil, the first word processing software for microcomputers.
- The Horizon introduced by North Star Computers, with a Z-80, 16K RAM, one 5.25 drive, 12 S-100 slots, and built-in serial I/O ($1999).
- H-8 Computer introduced by Heathkit as a kit, with an 8080 processor.
- Bill Mensch leaves MOS Technology, later starting his own design company with a contract to develop chips for MOS.
Apple incorporates, with Intel veteran Mike Markkula as its first chairman. He helps them obtain venture capital to get the business going., 
Apple moves from the garage owned by Steve Jobs’ parents to a building on Stevens Creek Boulevard in Cupertino, California.
Commodore PET 2001 first demonstrated at the Consumer Electronics Show in Chicago.
Apple II introduced at the First West Coast Computer Faire, with BASIC in ROM, color video, low and high resolution graphics, built-in speaker, game paddle inputs, and seven slots for peripherals. It is expandable to 48K RAM., 
First Apple II boards ship on May 10, 1977.,
Apple II flyer
BYTE magazine publishes an article by Steve Wozniak called “The Apple II”. It gives a hardware and firmware description of the computer.
MITS, the company that started it all with the Altair 8800 in 1975, is sold to Pertec Computer Corp. Poor management causes the company to fail within two years.
First Apple II systems ship. Standard configuration included 4K of memory, two game paddles, and a demo cassette with programs, costing $1,298. Home televisions are usually used for monitors.
Apple pays the $10,500 to Microsoft for half of the license fee for a floating point BASIC for the 6502. Randy Wigginton begins to work on adapting it to the Apple II.
TRS-80 introduced by Radio Shack, with a Z-80 processor, 4K RAM, 4K ROM, and cassette tape storage.
Wozniak, Espinosa, and Wigginton have to discontinue their attendance at the Homebrew Computer Club; work at Apple is now taking up all of their time.
Applesoft I, a 6502 version of BASIC purchased from Microsoft, is released on cassette.
“SWEET 16: The 6502 Dream Machine”, by Steve Wozniak, is published in BYTE magazine. It describes the 16-bit computer emulator he included in the Apple II Integer BASIC ROM.
Micro begins publication.
Commodore PET available for purchase, featuring a 6502 processor, 4K RAM, 14K ROM, and 8K Microsoft BASIC, for $595.
Apple Parallel Printer Interface Card released.
Wozniak begins work on a floppy disk drive and controller.