ITH
IT History Journal
March 22

March 22, 1965 — PDP-8, One of the First Minicomputers, Is Released

March 22, 1965

On March 22, 1965, Digital Equipment Corporation (DEC) released the PDP-8. Before that moment, computers were huge, expensive, and usually locked inside research centers or large corporations. They were called mainframes, and only a small group of specialists had access to them.

The PDP-8 was different. It was smaller, cheaper, and much more practical. For the first time, a computer could realistically be bought and used by laboratories, universities, and even industrial companies.

This is why the PDP-8 is often called one of the first minicomputers.

The people behind it

The PDP-8 was created at Digital Equipment Corporation (DEC), a company founded by Ken Olsen and Harlan Anderson. The engineering team made a series of important decisions:

  • use a 12-bit architecture instead of larger word sizes
  • simplify the instruction set
  • reduce cost wherever possible

These decisions made the PDP-8 not just smaller, but also easier to understand and use.

Why it mattered

The PDP-8 cost around $18,000 at launch — dramatically cheaper than most computers of that time. Because of that, it spread quickly:

  • universities used it for teaching and experiments
  • laboratories used it to control equipment
  • factories used it for process control

For many people, the PDP-8 was the first computer they could actually interact with directly. It also helped shape a new idea: computers should not be rare machines used only by experts — they should be tools.

A different way to work with computers

Unlike mainframes, the PDP-8 was often used in a more hands-on way. People could write programs, connect devices, and experiment.

This changed how engineers and programmers thought about computing. It moved the industry closer to interactive computing — something we now take for granted.

What came next: PDP-11

A few years later, DEC released the PDP-11 — a more elegant architecture with better instruction design and stronger support for operating systems. It became one of the most influential computers in history. Many concepts from the PDP-11 later appeared in Unix systems and modern computer architectures.

If the PDP-8 made computers accessible, the PDP-11 made them truly powerful and flexible.

PDP-8 emulator (browser) · Original DEC manuals