# [TECH] Personal Computer

**The Personal Computer (PC)** brought computing from corporate data centres to individuals, enabling word processing, spreadsheets, desktop publishing, and eventually the Internet.

## Overview

The Altair 8800 (1975, MITS) was the first commercially successful kit PC. The Apple II (1977) and IBM PC (1981, with Microsoft DOS) established the PC as a mass-market product. The graphical user interface (Xerox PARC, 1970s; Apple Macintosh 1984; Windows 3.1, 1992) made computing accessible. The PC created markets for microprocessors (Intel x86), operating systems (Microsoft), and packaged software. By 1995, 150 million PCs were installed globally; by 2023, ~2 billion.

## Key Actors

- **Companies**: IBM (1981 PC), Apple (1976), Microsoft (1975), Intel (1968), Compaq (1982), Dell (1984)
- **Inventors**: Ed Roberts (1941–2010, Altair), Steve Jobs (1955–2011), Steve Wozniak (1950–)

## Key Patents

- Apple patent portfolio covering GUI elements; IBM PC architecture was open, enabling the clone industry.

## Economic Value

PC market: **USD 270 billion/year** hardware (2023, IDC). Software and services enabled: USD 500B+/year. The PC created the conditions for the internet, e-commerce, and digital economy worth USD 10T+/year.

## Notes

IDC *PC Market Tracker* Q4 2023. Microsoft alone has a market cap of USD 3T, mostly attributable to PC-era software.

## What This Enables

- **[TECH] Internet & World Wide Web** — Web browsers running on PCs were the primary interface that drove mass adoption of the internet.
- **[TECH] Cloud Computing & Big Data** — The PC era created software ecosystems and enterprise IT that migrated to cloud when networking became fast enough.

## Discovery Character
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**Surprise level**: High — IBM's internal study in 1975 estimated the total world market for personal computers at 275,000 units over the lifetime of the product. By 1985, 30 million PCs per year were being sold. DEC's founder Ken Olsen said in 1977 "there is no reason anyone would want a computer in their home."
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**Mode**: Edisonian/hobbyist. The PC was not invented by a corporation with a systematic R&D programme. It emerged from the Homebrew Computer Club, the Altair kit (MITS, 1975), Jobs and Wozniak in a garage (Apple II, 1977), and hackers copying and extending each other's work. IBM's entry (1981) was systematic but relied on an open architecture that created the clone industry by accident. The consumer market was discovered by iteration and user feedback, not market research.
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# Parents

* [TECH] Integrated Circuit
* [TECH] Integrated Circuit