Until the mid-1970s, owning a computer was something for large companies, research centres and government bodies. Within a few years the situation changed radically: computers arrived on office desks and in homes. The shift was not the work of a single company, but of a series of products, enthusiasts and programs that fed one another. Going through them in order helps explain how the market we know was born.
The Altair 8800
The January 1975 issue of the American magazine Popular Electronics featured on its cover the Altair 8800, made by a small Albuquerque company, MITS, founded by Ed Roberts. It was sold mainly as an assembly kit, at a price an enthusiast could afford, and used the Intel 8080 microprocessor.
In its basic configuration the Altair was very spartan: it had no keyboard and no screen. It was programmed by flipping a row of switches on the front panel, and results were read from a row of small lights. Yet it was an immediate success: for the first time an individual could own a real computer.
Microsoft is born
Two young men, Bill Gates and Paul Allen, read the article and offered to write a BASIC interpreter for the Altair. They developed it in a few weeks, largely using a simulator on a bigger computer, and got it running on the real machine at the first serious attempt. In 1975 they founded Microsoft, whose first business was precisely selling programming languages for microcomputers.
The enthusiasts
In March 1975 the Homebrew Computer Club met for the first time, in the Menlo Park area of California, a group of enthusiasts who exchanged ideas, schematics and programs. Among the participants was Steve Wozniak, who single-handedly designed a computer much easier to use than the Altair. With Steve Jobs he founded Apple and in 1976 began selling it as the Apple I: a pre-assembled board to which the user added a keyboard, power supply and television set.
1977: three ready-to-use computers
1977 is often regarded as the year the personal computer became a product for a broader public. Three machines came out sold fully assembled, with a keyboard and the ability to connect a screen:
| Computer | Manufacturer | Distinctive feature |
|---|---|---|
| Apple II | Apple | Colour graphics, expansion slots |
| PET 2001 | Commodore | Built-in monitor and cassette recorder |
| TRS-80 | Tandy / Radio Shack | Sold through the Radio Shack chain of stores |
There was no longer any need to solder components: you bought the machine, switched it on and could start programming in BASIC.
The first "killer application"
For many buyers, though, programming was not the point. They needed a concrete reason to buy a computer. It arrived in 1979 with VisiCalc, the first spreadsheet for personal computers, developed by Dan Bricklin and Bob Frankston for the Apple II.
VisiCalc displayed a grid of rows and columns. You entered numbers and formulas; when you changed a value, all the linked results were recalculated instantly. For people preparing budgets and forecasts, until then redone by hand on paper at every change, it was an enormous transformation. Many people bought an Apple II in order to use VisiCalc. Ever since, the term killer application has been used for software that on its own justifies buying a platform.
The IBM PC
IBM, the largest computer manufacturer in the world, was watching the phenomenon. To enter the market quickly it chose an approach unusual for its corporate culture: a small team, components bought from outside suppliers and an open, documented architecture.
On 12 August 1981 IBM introduced the Personal Computer, model 5150. It used the Intel 8088 processor and an operating system supplied by Microsoft, which had bought and adapted a pre-existing system, 86-DOS from Seattle Computer Products. IBM distributed it as PC DOS, while Microsoft kept the right to sell its own version, MS-DOS, to other manufacturers.
The effect of IBM's choices
These two decisions, standard components and a non-exclusive operating system, had huge consequences. Other companies could build computers compatible with the IBM PC, able to run the same software. Compaq introduced one of the first successful compatibles, a portable model. Within a few years the market was dominated not by IBM but by the standard IBM had created, and value shifted towards whoever controlled the processor and the operating system.
Symbolic recognition came quickly: Time magazine chose the personal computer as "Machine of the Year" for 1982, in place of its usual person of the year.
What it teaches us
The story of the personal computer shows some mechanisms that have repeated themselves many times in the industry:
- Enthusiasts anticipate the market. Early users accept awkward products if they open up new possibilities.
- Software sells hardware. VisiCalc sold Apple IIs more than any technical specification.
- Open platforms grow faster, but those who create them do not always control the benefits.
In short
- The Altair 8800, on the cover of Popular Electronics in January 1975, was the first personal computer to find wide success among enthusiasts, and Microsoft's BASIC was born for it.
- In 1977 the Apple II, Commodore PET and TRS-80 brought pre-assembled computers to a wider public.
- VisiCalc, in 1979, was the first killer application and made the computer a work tool.
- The 1981 IBM PC, with its open architecture and MS-DOS, created the compatibles standard that still dominates today.
