---

General Precision LGP-21 Emulator – Useful Links

This page presents a number of links to documents, source code, object code, and utilities for the LGP-21.

General Information

Emulator Hosting Site

Home page for the emulator hosting site (this site). Contains links to run the emulator and access project resources and other related materials.

LGP-21 Software

A collection of paper-tape image file and related resources at bitsavers.org containing LGP-21 software.

LGP-21 Assembler, Tools, and Examples

A collection of LGP-21 utilities and examples from Rhys Weatherly, including an assembler and command-line emulator. There are also several newly-written example programs for the LGP-21 with both assembler source and loadable paper-tape image files.

LGP-21 Example Programs

A collection of LGP-21 example programs from Bill Kuker, including one that computes the Mandelbrot set. The source can be assembled using Rhys Weatherly's assembler above.

Tom Jennings' LGP-21 web site

A collection of information, documents, and images for the LGP-21. The system pictured here is the one restored by Usagi Electric.

Jürgen Müller's web site

Describes an FPGA replica project for the LGP-21 with links to some documents and software.

Technikum29 Museum

This institution in Germany has a German variant of the LGP-21, as well as a collection of manuals (mostly in German) and paper-tape image files in their GitHub site.

Miscellaneous

The Story of Mel

The story of Mel Kay, a legendary programmer for the Librascope LGP-30 and RPC-4000. Also see this annotated copy of the story and this web site about Mel himself (yes, he was a real person) and his famous hack.