PiDP-11: A Fully Operational PDP-11/70 Replica

PiDP-11 PDP-11/70-replica front panel

This is a PiDP-11, Oscar Vermeulen's 2/3-scale replica of the iconic PDP-11/70 minicomputer introduced by DEC in 1975. The PDP-11 is widely regarded as the most influential minicomputer in history and was used by researchers at Bell Labs from 1970 onwards to give the world AT&T UNIX. And with the 11/70 in 1975, DEC achieved peak blinkenlights.

A team at UC Berkeley began extending AT&T UNIX in the mid-1970s and developed the Berkeley Software Distribution (BSD) flavour of Unix. Many of the techniques and technologies underlying modern operating systems and the Internet were introduced in BSD. For example, the first widely distributed implementation of TCP/IP networking and the sockets API arrived with 4.2BSD in 1983, and OpenSSH was pioneered by the OpenBSD project and now ships on very nearly every server on earth. BSD persists directly in FreeBSD, OpenBSD and NetBSD and is the ancestor of Apple's operating systems - macOS, iOS, watchOS, etc. - and Sony's PlayStation operating systems have been FreeBSD-based since the PS3. Even systems with little or no BSD code speak Berkeley's language - Windows' Winsock, the Linux networking API and the IEEE POSIX sockets standard are all closely modelled on BSD sockets.

A licensing lawsuit between AT&T and the Berkeley Unix people in the early 1990s (USL v. BSDi, filed 1992, settled 1994) gave Linux the incentive and opportunity to spread and attain widespread adoption. Today, almost all smartphones and the array of networks, servers and data centres required to deliver Internet and cloud services run on derivatives of BSD Unix or the Unix-workalike Linux.

Some fun & and interesting videos: Beige-o-Vision introduces the PDP-11 and the PiDP-11 kit, CuriousMarc talks to Oscar about his DEC PDP kits, Brian Kernighan talks at VCF East 2025 on life & Unix at Bell Labs, and an AT&T Archive film from 1982 features interviews with Brian, Dennis Ritchie, Ken Thompson and other key players in the Unix story.

Beige-o-Vision: an introduction to the PDP-11 and the PiDP-11 kit CuriousMarc talks to Oscar Vermeulen about his DEC PDP replicas Brian Kernighan at VCF East 2025 on life and UNIX at Bell Labs AT&T Archive film from 1982 on the making of UNIX

Wikipedia - Digital Equipment Corporation PDP-11 Minicomputer

Ars Technica - PDP-11: The Most Influential Minicomputer of All Time

This page has been served by 2.11BSD httpd, a lightweight web server written in K&R C and running on 2.11BSD Unix on the emulated PDP-11/70 itself.


Dublin 15.6°C at 23:45 on 26 Sep 2026
gdansk reports 20.5°C at 23:45 on 26 Sep 2026
Sunrise at 07:17, solar altitude 35.29° at noon 13:16 and sunset at 19:14 on 26 Sep 2026

Weather data by Open-Meteo.com, licensed under CC BY 4.0. Solar data by sunrise-sunset.org. Times shown converted from Unix epoch to local time; no other changes made.