Guided tour of the Lisp machines
This is the place to begin if CADR and Genera are unfamiliar. The knowledge base elsewhere explains and specifies the systems; the Tour teaches you how to sit down at one, understand what the screen is saying, move between programs, and try the major facilities without assuming prior Lisp-machine experience.
Choose a story
- A working session on the MIT CADR follows one first-time user from the Listener through Zmacs, Help, Inspector, Peek, layout, tracing, debugging, terminals, compiler tools, demonstrations, and recovery.
- A working session in Symbolics Genera follows one first-time user through activities, the Command Processor, Zmacs, presentations, Document Examiner, Inspector, Frame-Up, Debugger, Accepting Values, development tools, communications, and administration.
The two systems are related but not interchangeable. CADR's System 303 software is a maintained descendant of the MIT Lisp Machine environment. Genera 8.5 is a later Symbolics system with activities, the Command Processor, and Dynamic Windows layered over evolved TV facilities. Each tour names its exact profile when behavior differs.
Stories first, references second
Read a guided session linearly. Concepts are introduced when the story first needs them, and each stable layout or interaction change is accompanied by a reviewed still or short teaching animation.
Afterward, use the compact orientations and application atlases as references:
The atlases remain complete because not every catalog area makes sense as a visible stop in a user story. A Try it instruction was verified against source, manuals, or the preserved runtime identified on the page. A Boundary note means the preserved environment cannot safely or honestly demonstrate that path. Many network, printer, tape, disk-repair, and hardware-diagnostic commands were designed for a configured machine room, not a disposable emulator.
Reading the pictures
The stills and animations are evidence, not decoration. Captions identify the system, state, and action they establish. Every animation now comes from one coherent interaction: either a continuous recording or ordered action-boundary captures. Staged clips do not claim real-time latency or omitted pointer motion.
The images have individual publication reviews. They do not distribute the software, fonts, documentation corpus, world image, or load band, and they are excluded from any repository-wide license. See the screenshot publication review.
Keep a lifeline
Three ideas will save you while exploring either machine:
- Help is contextual. Ask while you are in the program or mode you want to understand.
- Abort backs out of an interaction. It is not the same as deleting the current application.
- Selection is not launching. System and Select gestures often find and expose an existing window; explicit creation is a separate operation.
Those differences are part of the systems' UI language, not historical quirks to paper over with modern desktop terminology.