History of the Personal Computer

Personal computers are a very popular item these days, with computer companies topping sales charts and computer company’s C.E.O’s becoming the world’s wealthiest people. 25 years ago that was not the case. Computers were around; most large companies had access to them and even a few of the smaller ones had timesharing access, yet most people had never used a computer. Those of the working class may have heard of computers but that was probably the closest they had ever come to a computer. This all changed over a period of 20 years. This is the history of the device that changed the world, the personal computer.

First we must define what a personal computer is:
-It must be digital
-It must be mostly automatic
-It must be accessible to the public as a kit, complete product or as plans
-It must be small enough for the average person to move
-It must be cheap enough for the average person to afford ($10,000 max.)
-It must be simple enough for the average person to use with out special training.

With these requirements in mind let’s begin the history of the personal computer.


PThe line up....
 1950: The Simon
 1955: GENIAC
 1959: Heathkit EC-1
 1961: Minivac 601
 1965: DEC PDP-8
 1966: Honeywell Kitchen Computer
 1967 & 1969: Paperclip Computer and Arkay CT-650
 1970: Imlac PDS-1
 1971: Kenbak-1
 1972: HP 9830
 1972: Intel SIM4
 1973: Micral
 1973: Xerox Alto
 1973: Scelbi-8H
 1974: Mark-8
 1975: Altair 8800
 1975: IBM 5100 Portable Computer
 1976-77: Apple I & II
1981: IBM PC
1983: Lisa
1984: Macintosh 128


Produced by: Berkeley Enterprises
Model: Simon
Introduced: 1950
Price: approx. $300
Technology: Relay switches

The Simon was the first personal computer, designed by Edmund Berkeley of Berkeley Enterprises. He published his plans for Simon in a series of Radio Electronics from 1950 to 1951.


Produced by: Berkeley Enterprises
Introduced: 1955
Price: $19.95
Technology: Electric rotary switches

The GENIAC, designed by Edmund Berkeley of Berkeley Enterprises. It was very cheap, digital, small, and it was user programmable. Its output was a series of small lights. It could be programmed to play Tic-Tac-Toe, Nim, Monopoly, and to do calculations. There were also similar machines that were sold under several different names.


*Heathkit EC-1*

Produced by: Heathkit
Model: EC-1
Introduced: 1959
Price: $199
Technology: Analog tubes

The EC-1 was a small, cheap desktop computer that was introduced in 1959, it could solve certain problems yet it is not a personal computer because it uses analog technology, not digital.

*Minivac 601*

Produced by: Scientific Development Corporation
Model: Minivac 601
Introduced: 1961
Price: $135
Technology: Relay switches

This small computer was based on the technology that powered the IBM Mark 1, but instead of the thousands of electromagnetic-relays used in the 8 foot high, 50 foot long Mark 1, this desktop machine had only 6 relays



Produced by: DEC (Digital Electronics Corporation)
Model: PDP-8
Introduced: 1965
Price: Unknown
Technology: SSI, core memory

The PDP-8 was one computer in a line of many PDP's, but this one was designed for the home market yet it's price kept it out of the market, plus the fact it needed racks of equipment to function correctly. Although the PDP-* may had not be a hit it's self it inspired Steven Gray, founder of the Amateur Computer Society to start his organization and to publish a newsletter about home computers. The publishing of the ACS Newsletter was the start of the hobbyist computer movement predicted by Edmund Berkeley of Berkeley Enterprises more than 20 years earlier.

*Honeywell Kitchen Computer*
Produced by: Honeywell
Model: Kitchen Computer (based on DDP-516)
Introduced: 1966
Price: $7000
Technology: SSI, core memory

Honeywell took a stab at the computer market using this....., well very interesting computer for the kitchen, you could even cut veggies on it (yes, it did have a cutting board!). This computer served as the IMP's the powered ARPANET, an early form of the Internet (and no, they didn't have cutting boards, yet the technology was cutting edge......HAHAHAHAhahaha(ahem.).)


*Paperclip Computer*

Produced by: (actually written by) Alcosser, Phillips, and Wolk (Commercial version produced by: COMSPACE)
Model: Paperclip Computer (Commercial model: Arkay CT-650)
Introduced: 1967 (Commercial version introduced: 1969)
Price: $3.75+parts ($3.75 was for the book)(Commercial version cost:$1000)
Technology: Paper clips, tin can, knife switches, and other household items (Commercial version: Relay switches)

The "Paperclip Computer" actually came in a book "How To Build A Working Digital Computer" written by Alcosser, Phillips, and Wolk. The book tells you how to make a computer using household items i.e. paperclips. The commercial version was produced by a company named COMSPACE and was called the Arkay CT-650.

(COMSPACE's Arkay Ct-650)

*Imlac PDS-1*

Produced by: Imlac
Model: PDS-1
Introduced: 1970
Price: Unknown
Technology: SSI, core memory

The Imlac PDS-1 was a personal computer/ workstation that was the first computer to use a GUI (Graphical User Interface). A GUI is a program that allows the user to manipulate digital data using abstract, non-exsistant representations of the programs or data, Windows is an example of a GUI. The Imlac PDS-1 was based on the PDP-8 and PDP-10. P.S. The PDP-10 also demonstrated that GUI that the PDS-1 used.



Produced by: Kenbak
Model: Kenbak-1
Introduced: 1971
Technology: MSI

The Kenbak-1 was designed and sold by John Blankenbaker. The Kenbak-1 was sold through small ads in Scientific American in 1971.

*HP 9830*

Produced by: Hewlett Packard
Model: 9830A
Introduced: 1972
Price: $5975
Technology: MSI

This small, little known computer was a very neat computer indeed. It had it's own display, keyboard, and even BASIC (a programming language) built in, but these computers were hardly known because they were marketed to engineers and scientists.


*Intel SIM4*

Produced by: Intel
Model: SIM4-01
Introduced: 1972
Price: Unknown
Technology: 4004/LSI

The Intel MCS-4 based SIM4 is billed as the first microcomputer, but not the first personal computer.


Produced by: Micral
Model: Micral
Introduced: 1973
Price: $1750
Technology: 8008/LSI

A French microcomputer that used the Intel 8008 chipset.



Produced by: Xerox
Model: Alto
Introduced: 1973
Price: N/A
Technology: MSI

This computer could be said to be the most innovative computer ever. It had a GUI, a mouse, an object-oriented operating system, and fast networking. It had features that took 10, even 20 years to become common place. Oddly enough this gem of computer was never commercially produced but a later version the STAR was released with little success.


Produced by: Scelbi
Model: 8H
Introduced: 1973
Price: $565
Technology: 8008/LSI

This personal computer was designed by Nat Wadsworth and available from the manufacturer as a kit or as a completed computer.



Produced by: (Plans published by:) Radio Electronics
Model: Mark-8
Introduced: 1974
Price: $5 for plans
Technology: 8008/LSI

This computer, designed by Jon Titus, was the computer that made the computer hobbyist movement into a mainstream hobby.


Produced by: MITS
Model: Altair 8800
Introduced: 1975
Price: $439 for kit, $621 assembled
Technology: 8080/LSI

This computer is one of the most over hyped computers around. Many bill it as the first personal computers ever, yet as you can see it was obviously not the first. It did sell in high quantities and was the first computer to use Microsoft software but that doesn’t make it very special.


*IBM 5100*

Produced by: IBM
Model: 5100
Price: $9000- $20,000
Technology: LSI

Unknown to many this computer was IBM’s true first entry into the personal computer market. But its high price kept out of the reach of most people. This was one of many of IBM’s failed attempts to enter into the personal computer markets.

*Apple I & II*

Produced by: Apple Computer
Model: Apple I and Apple II
Introduced: Apple I- 1976
            Apple II- 1977
Price:    Apple I- $666
          Apple II- $1295

Technology: Mostek 6052/LSI (A pin by pin replacement of the Motorola 6800)

The Apple I and Apple II are very important computers in the history of personal computers. The Apple I was the original computer produced by Apple's Steve Woziank and Steve Jobs. These two computer hobbyists created a very succesful empire with the second version of the Apple I, the Apple II this computer was very important to the personal computer industry and to the history of personal computers because it brought personal computers from the garages and basements of computer "geeks" to the offices and desks of businesses and homes everywhere. 


Produced by: IBM
Model: 5150 PC
Introduced: 1981
Price: ?
Technology: 8088/VLSI

This was the big bang for the personal computer industry, transforming it from a small, hobbyist movement into the everyday item that has changed our lives forever. The PC might not have been IBM’s first personal computer but it was its greatest. The PC was very important because people who had never thought of buying a personal computer did.



Produced by: Apple Computer
Model: Lisa
Introduced: 1983
Price: around $10,000
Technology: Motorola 68000 16-bit processer/ up to 512 kilobytes RAM

The Apple Lisa was a risky next generation project that was Steve Jobs' pet project. The Lisa used the GUI system which was tested in systems like the Alto, and the Imlac but it never had a commerical chance. Even though the Lisa was very advanced it was plagued with problems. Apple had decied to not publish a development kit for developers to create programs for the Lisa until a year after release. The high price of the Lisa and development issues doomed the Lisa from the start but Apple was ready.....

*Macintosh 128*

Produced by: Apple Computer
Model: Macintosh 128
Introduced: 1984
Price: $2,495
Technology: Motorola 68000 16-bit processer/ up to 128 kilobytes RAM

The Macintosh 128 looks like a Lisa that has been stood up on its side and shrunk. The Macintosh learned from all of the mistakes that the Lisa: It was cheaper ($2,495) and it had a large software library even before it was released ( developers made programs on Lisa II's for the Macintosh). This computer finally brought the GUI into the reach of the average joe and was probably the first personal computer in which you could pull it out of the box, plug it in, hook-up the keyboard, and began working. The Apple iMac is heading back towards the all-in-one appliance computer.


Obsolete Computer Museum

Blinkenlights Archaeological Institute


The History of Computers, Les Freed, 1995, Ziff-Davis Press, Emeryville, California.

Apple History