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qrush/unix

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Mirror of the Restoration of 1st Edition UNIX kernel sources from pdf document.

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Type
Open Source
Visit Website GitHub (38 stars)

About qrush/unix

The qrush/unix repository is a mirror of the restoration of the 1st Edition UNIX kernel sources from the original PDF document. It provides both the kernel source code and userland binaries required to run 1st Edition UNIX on a PDP-11 simulator (simh). The project includes build scripts to assemble the kernel, create filesystem images (RF0, RK0, and tape), and boot into a fully functional UNIX environment. Detailed build instructions guide users through downloading simh, building the PDP-11 simulator, and compiling necessary tools such as mkfs, ml, and apout. Users can log in as root, navigate the filesystem, use the ed editor, and even enable multiple remote logins via telnet. Documentation links to original manuals and the preliminary implementation document are provided, making this an invaluable resource for studying early UNIX internals and running the original operating system.

Key Features

Includes complete kernel source code and userland binaries from 1st Edition UNIX
Provides build scripts to compile tools and create bootable disk/tape images
Designed to run on the SIMH PDP-11 simulator (version 3.8-0 or later)
Offers a fully bootable UNIX environment with login, shell commands, and ed editor
Supports multi-user telnet access (up to 8 simultaneous logins)
Documents build and run processes with clear instructions and links to original manuals

Pros & Cons

Pros
  • Authentic restoration of the original 1st Edition UNIX with minimal modifications
  • Open source and freely available on GitHub
  • Well-documented build process including simulator setup
  • Includes both kernel source and binary images for immediate use
Cons
  • Requires familiarity with PDP-11 simulator (SIMH) and vintage UNIX commands
  • Limited text editor (ed) with steep learning curve for modern users
  • No modern features like networking or graphical interface
  • Build process may be complex for beginners

Best For

Educational resource for understanding early UNIX kernel architectureHistorical computing research and preservationRunning legacy software or experimenting with PDP-11 environmentTeaching operating system concepts with authentic 1970s UNIX

FAQ

What is included in this repository?
The repository contains the kernel source code, userland binaries, build tools (mkfs, ml, apout), and scripts to create bootable disk and tape images for 1st Edition UNIX.
How do I run 1st Edition UNIX?
Download the SIMH simulator (v3.8-0+), build the PDP-11 simulator, copy the executable to the tools/ directory, then run 'make' at the repository top level. Finally, execute ./simh.cfg to start the simulator and log in as root.
What simulator is required?
The SIMH PDP-11 simulator version 3.8-0 or later is required. Older versions may need patches.
Can I log in as multiple users?
Yes, the system supports up to 8 remote logins via telnet to localhost port 5555.
What documentation is available?
The repository links to the original 1st Edition UNIX manual, the Preliminary Unix Implementation Document, and PDP-11 hardware handbooks.