Cornerstone

Cornerstone
Utility
Relational database
[[File:|class=ifwiki-infobox-image]]
Link
Developer	Infocom
Format
Interaction style
System	MS-DOS
System details
Latest version	1985
Status	Unavailable
Implements
Uses
License
Notes
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Cornerstone was a relational database for the IBM PC platform released by Infocom in 1985. It is generally considered one of the chief factors that led to the failure of the company.

VM reverse-engineering

Cornerstone's virtual machine (VM) was known as the Mu Machine or possibly μ-machine.

In 2002, John Elliott documented its bytecode format to some extent, and wrote a disassembler.

In 2026, Tara McGrew fully reverse-engineered the system to write a toolchain including:

• Linchpin, a re-implementation of the virtual machine (taking the role of MME.EXE, the "Mu Machine Emulator", from the original software distribution)
• Chisel, an assembler for the VM (input for which can be produced by a version of ZILF)

This effort was published on 1 April 2026, purportedly as the discovery of lost ports of Cornerstone for the Atari ST and Amiga. Initial demos included Zork I and the Bad Apple demo running within Cornerstone.

Links:

• Cornerstone's VM (was: Cornerstone for Atari) (IntFiction forum thread started 01-Apr-2026).
• Source code for Linchpin/Chisel/etc.
• Write-up by Andrew Plotkin (05-Apr-2026).

Links

• Wikipedia: Cornerstone (software).
• Download or view contents of csdemo.zip, at the IF Archive - a demo of Cornerstone.
• Cornerstone at The Obsessively Complete Infocom Catalog.