muir-sys

The Lisp Machine system for QUUX, the machine that muir-sim and muir-fpga evolve from the MIT CADR, continuing where System 100 left off.

The starting point is the MIT CADR and its system as MIT last left it. System release 99.32 is the content of a backup of OZ recovered by the Tapes of Tech Square project, "possibly the last backup and version of the Lisp Machine for the CADR". This system is forked from System 100, LM-3's release of that content, brought up and fixed, under the AGPL.

The aim is to evolve the system, not to change it radically. It moves on in steps, each a release built from this repository. Backward compatibility is not an aim.

The CADR's line continues on the cadr branch, from System 1001, with numbers in the 1000s: its next system is 1002. main is QUUX's line, whose numbers are the 2000s: from System 2000 the system on main runs only on QUUX.

QUUX

QUUX is the CADR evolved, the machine muir-sim runs as quux and muir-fpga builds. It keeps the CADR's architecture and improves on it in two directions: performance and capacity, and modern computing, such as the display's resolution, block storage and the network. Each improvement is a hardware revision, and the machine says which it has: MACHINE-ID, a functional source, gives the revision, and its feature page, the read-only first 64 words of its register page, gives its sizes. The system reads both at boot rather than assuming them.

What the system on main uses so far:

	QUUX	the CADR
level-1 map entry (revision 1)	6 bits: 63 level-2 blocks, 504K words mapped at once	5 bits: 31 blocks, 248K words
PDL buffer (revision 2)	16K words	1K words
multiply and divide (revision 3)	one instruction each	32 steps
the 60-cycle clock (revision 4)	the processor's own tick	the display's vertical interrupt
display	the video controller, a 1-bit frame buffer, 1920 by 1080 by default, sized from the feature page	768 by 963, with a sync program

QUUX's microcode is MIT's 323 changed, released first as microcode 2000 with boot PROM 2000 and System 2000: QUUX's numbers are the 2000s, the CADR's the 1000s. main is now System 2002, on microcode 2002 and boot PROM 2002. Both are for QUUX alone and stop on anything else, as a band from main does. docs/release-2002.md records each change as it is made; docs/booting.md follows a machine from power-on to Lisp.

System 2000

System 2000 is the first release for QUUX, from main: the first system for QUUX, as above, with the herald naming the site and the machine, and fixes taken from lmz-sys, bishop's line.

System 1001

System 1001 removes unused machine and host support, dead interfaces and obsolete compatibility code. It fixes the error handler and TELNET input, and adds unattended cold loading through a generated SYS: SITE; COLDRUN LISP script. The system is built by a clean recompile, a new cold load, QLD and a saved band. docs/release-1001.md records the changes.

System 1000

System 1000 is System 100 fixed and cleaned up: the same sources and microcode 323, the faults that stopped it rebuilding itself repaired, the material that is not MIT's left out. It continues where System 100 left off, and the number steps from 100 to 1000.

In short, the fault that stopped a cold load in silence and MINI's two stream faults are fixed; the routing table covers every subnet, and MINI finds its file server by itself; about forty faults are fixed across the tree, and 36 of LM-3's later fixes are taken, one at a time; the tape, LMFILE and Xerox printing systems are gone; only System is patchable; and what is not MIT's, or not wanted, was never imported. The band is compiled by the system itself, and the microcode is assembled from its sources. docs/release-1000.md records every change.

Releases

There are no patches, only releases. Every change reaches a band through a full rebuild of the system from its sources, so a release is a whole number --- 1000, 1001, 1002 --- and never 1000.1. A running band is not updated in place; it is replaced by the next release's band. The Lisp Machine's patch system remains in the tree, because it keeps track of the release number, but no patch files are written or loaded.

Each release is published on this repository's Releases page: a disk ready to boot (for QUUX a VHD with a GPT, for the CADR a disk pack), and the system's sources with their assembled microcode and an example site; a QUUX release also carries its boot PROM. From 1002 and 2000 on, SHA256SUMS gives the files' checksums. The release's own text says how to run them.

The machine it runs on

This is the system. Three projects provide the machine:

muir-sim	the simulator, of the CADR (cadr) and of QUUX (quux)
muir-fpga	the CADR and QUUX on FPGA boards
ozd	the Chaosnet services daemon: files, time, host table, TELNET; the CADR's line uses it, and QUUX, which has no Chaosnet interface, does not

Layout

sys/	the Lisp Machine sources, as the machine sees them: SYS: SYS2; is sys/sys2/
site/	the site files a machine loads, for the example site MIT
docs/	how the system is built, and what has been found out about it
tools/	lispm-check, which checks a Lisp change on a band in seconds, its files served by quux's file device

Documents

• docs/building.md --- building the system from source: compiling, the cold load, QLD, saving a band, assembling the microcode, and writing a release pack.
• docs/release-2002.md --- every change System 2002, in progress on main, makes to System 2001.
• docs/release-2001.md --- every change System 2001 makes to System 2000.
• docs/release-2000.md --- every change System 2000 makes to System 1001.
• docs/booting.md --- how a machine boots, from power-on through the boot PROM and the microcode to the first macroinstruction.
• docs/release-1001.md --- every change System 1001 makes to System 1000.
• docs/release-1000.md --- every change System 1000 makes to System 100.
• docs/upstream-changes.md --- the fixes LM-3 made after System 100, and which of them were taken.
• docs/fonts.md --- the fonts are the last binaries with no source here: what became of their sources, and where copies of some survive.
• docs/lispm-check.md --- tools/lispm-check: checking a Lisp change on a band in seconds, from a checkpoint.

Faults found along the way are logged as issues in this repository.

How it was written

The system sources are MIT's, by way of LM-3. The changes here, the builds and the documents here are made by Claude Code, on Anthropic's Opus and Fable models.

Copying

muir-sys is licensed under the GNU Affero General Public License, version 3 or later; see LICENSE. LM-3 released System 100 under those terms, and it continues under them.

The files carry MIT's copyright notices, the code having been recovered from MIT's backup tapes, and a few carry other notices. NOTICE sets out where the sources come from, the terms they are distributed under, and every notice that is not MIT's.