Personal Computers

In the mid-1970s, the increased availability of inexpensive microprocessors led to the development of “personal computers”– affordable computers intended for a single user. Typically, the first systems were available only as kits and required technical knowledge to build and operate. Clubs, newsletters, and magazines arose to facilitate an exchange of information between enthusiasts. By 1977, Commodore, Tandy Radio Shack and Apple were producing personal computers in large numbers.

Most corporate managers hesitated to embrace the concept until IBM validated the market with its entry in 1981. The IBM Personal Computer (PC) caused an explosion of IBM-compatible hardware and software and sparked a new industry based on Intel microprocessors and Microsoft operating systems.

Kenbak-1
1971
Kenbak Corporation, United States

In 1971, Scientific American magazine advertised the Kenbak-1 computer. Designed by John V. Blankenbaker, the machine featured standard small- to medium-scale integrated circuits, relied on switches and lights for input/output, and included a 256-byte memory. Kenbak Corporation closed its doors in 1973 after selling only forty computers to schools and hobbyists. The Kenbak won The Computer Museum’s “Earliest PC Contest” in 1986.

Memory Type: Semi Speed: 2,500 Add/s Memory Size: 256 bytes Cost: $750.00 Memory Width: (8-bit)

Micral Microcomputer
1973
R2E, France

Not only was the Micral probably the first commercially available, fully assembled computer to include a microprocessor, but it was also the first machine referred to as a "microcomputer" in print. Incorporating the new Intel 8008 processor, the Micral was available in 1973, 18 months before the Altair 8800 kit appeared on the cover of Popular Electronics magazine. R2E (Réalisations Etudes Electroniques) originally designed the Micral for use by the French National Institute for Agronomic Research(INRA).

Memory Type: Semi Speed: 0.2 MHz Memory Size: 256 bytes Cost: $1,950 Memory Width: (8-bit)

Altair 8800 Microcomputer System
1975
MITS, United States

The cover story of the January 1975 edition of Popular Electronics magazine featured the Altair 8800 microcomputer kit. Using a new 8-bit Intel 8080 CPU and a price tag just under $500, the Altair became the most popular "homebrew" computer to date. It inspired Harvard University student William Gates to write a BASIC interpreter so that users would not be forced to use assembly language to program the machine. He called his new company "Micro-Soft."

Memory Type: Semi Speed: 1 MHz Memory Size: 256 bytes Cost: $397 (Kit) Memory Width: (8-bit)

Xerox Notetaker
c. 1976
PARC, United States

Xerox Palo Alto Research (PARC) researcher Alan Kay intended the Notetaker to be a portable universal learning appliance. Built by Doug Fairbairn, the computer, weighing 48 pounds, featured an internal monitor and floppy disk drive as well as a mouse. Like the Xerox Alto, the Notetaker used a version of the Smalltalk-78 operating environment.

The Notetaker’s design set the trend for many later “luggable” computers such as the Osborne 1 and the Compaq Portable. Xerox built about ten Notetaker prototypes and never offered the machine for sale as a product.

Memory Type: Semi Speed: 1 MHz Memory Size: 128K Cost: $50,000 Memory Width: (8-bit)

Apple I
1976
Apple Computer, United States

Steve Wozniak first showed the prototype Apple-1 to his friends at the Homebrew Computer Club in April 1976. For $666.66 buyers received a blank printed circuit board, a kit of parts, and a 16-page assembly manual. In order to make a useful computer, one had to add a power supply, keyboard, and display. Wozniak and his high-school friend Steve Jobs went into small-scale production when The Byte Shop in Mountain View ordered fifty assembled boards.

Apple II
1977
Apple Computer Inc., United States

Inspired by the success of the Apple-1 and guided by friend co-founder Steve Jobs' vision of an expandable user-friendly personal computer, Steve Wozniak designed the Apple II in 1977. The self-contained unit housed all electronics, a keyboard, a power supply, and the BASIC language stored in the machine's permanent memory. A standard television could serve as the display.

With the introduction of the floppy disk drive in 1978 and the spreadsheet program VisiCalc in 1979, the Apple II became a blockbuster product with a devoted following. Production of the Apple II family finally ended in 1993.

Memory Type: Semi Speed: 1 MHz Memory Size: 48K Cost: $1,298 Memory Width: (8-bit)

TRS-80 Model 1
1977
Tandy Radio Shack, United States

Until 1977, most home computers were available only as kits or required signficant technical ability to use. The TRS-80 belonged to a new generation of inexpensive personal computers designed for the mass market. It arrived completely assembled and included a monitor, keyboard and pre-installed BASIC software. Also, the machine could store data and programs using a standard audiocassette recorder.

Memory Type: Semi Speed: 1.77 MHz Memory Size: 4K Cost: $599.95 Memory Width: (8-bit)

IBM Personal Computer
1981
IBM Corporation, United States

Although IBM’s first personal computer arrived nearly ten years after others were available, the IBM Personal Computer (PC) instantly legitimized and expanded the market. Unlike most other contemporary IBM products, the PC incorporated both hardware (the Intel 8088 microprocessor) and software made by other companies. IBM published design details in their manuals that encouraged others to make copies or “clones” of the original machine, often with improved functionality. The IBM PC architecture quickly became an industry standard.

Memory Type: Semi Speed: 4.77 MHz Memory Size: 16K Cost: $1,565 Memory Width: (8-bit)

Osborne 1 Portable Computer
1981
Osborne Computer, United States

In 1981, Osborne advertised the first commercial portable computer. The Osborne 1 weighed 24 pounds and became its own carrying case by attaching the keyboard to the front of the unit. It was a success not only because of its size and low price, but because it also included an extensive software library worth more than the price of the computer itself. Designed by Lee Felsentein, the machine used a Zilog Z80 processor, and ran the CP/M operating system.

Memory Type: Semi Speed: 4 MHz Memory Size: 64K Cost: $1,795 Memory Width: (8-bit)

Commodore 64 Home Computer
1982
CBM, United States

With powerful audio visual capabilities, Commodore Business Machines originally developed the 64 as a programmable engine to support arcade games. Following the project’s abrupt cancellation, Commodore attempted to recoup its investment by remarketing the machine as a home computer. The 64 was less expensive than comparable computers and Commodore eventually sold more than 30 million units.

Memory Type: Semi Speed: 1 MHz Memory Size: 64K Cost: $595 Memory Width: (8-bit)