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COMPUTATIONAL MACHINES · 02

FORTH/77 STACK MACHINE

CORE READY
0 WORDS
SESSION 02 · BASE 10LEFT-TO-RIGHT WORD STREAM

FORTH/77 READY. OK

PLACE DATA FIRST; NAME THE ACTION AFTER IT.

PRESS STEP TO WATCH THE STACK CHANGE.

ok>
⌘/CTRL+ENTER runs · STEP executes one word · The right edge is the top of the stack
WORDS
STANDBY

STACK TRACE STANDBY

STEP will execute one word, showing exactly which values it consumes, rearranges, and produces.

WORD ENTRY UNIT

Every illuminated word is implemented. Select one to read its stack effect.

STACK MATH LOGIC FLOW
Forth

DATA FIRST.
ACTION AFTER.

λ

COMPUTATIONAL MACHINES · 03

LISP/58 SYMBOL MACHINE

CORE READY
0 NAMES
SESSION 03 · READ/EVAL/PRINTPREFIX SYMBOLIC EXPRESSIONS

LISP/58 READY. NIL

TYPE AN S-EXPRESSION; THE MACHINE WILL REDUCE ITS TREE.

PRESS STEP TO WATCH BINDINGS AND RETURNS.

λ>
⌘/CTRL+ENTER evaluates · STEP reduces one form · Definitions remain in this session
FORMS
STANDBY

SYMBOL TRACE STANDBY

STEP will reveal the active expression, its evaluated arguments, lexical bindings, and returned value.

SYMBOL ENTRY UNIT

Parentheses expose structure. Select a named form to open its reference card.

FORM LIST MATH LOGIC
Lisp

CODE IS DATA.
DATA IS CODE.

⊢

COMPUTATIONAL MACHINES · 04

PROLOG/72 LOGIC MACHINE

CORE READY
0 CLAUSES
SESSION 04 · DEPTH-FIRST SEARCHHORN CLAUSE INFERENCE

PROLOG/72 READY. ?-

STATE FACTS AND RULES; THEN ASK WHAT FOLLOWS.

PRESS STEP TO WATCH THE PROOF TREE OPEN.

?-
⌘/CTRL+ENTER proves · STEP performs one inference · Use ; conceptually for the next solution
PROOF
STANDBY

INFERENCE TRACE STANDBY

STEP will select the leftmost goal, try a matching clause, reveal its variable bindings, and expose every choice point.

LOGIC ENTRY UNIT

Build clauses with syntax keys; select a concept to open its logic card.

SYNTAX VARIABLE CONCEPT PREDICATE
Prolog

STATE RELATIONS.
SEARCH FOR PROOF.

◫

COMPUTATIONAL MACHINES · 05

SMALLTALK/80 OBJECT MACHINE

IMAGE READY
0 CLASSES · 0 OBJECTS
WORKSPACE 05 · LIVE IMAGERECEIVER → SELECTOR → METHOD

SMALLTALK/80 IMAGE READY.

EVERY VALUE IS AN OBJECT; EVERY ACTION IS A MESSAGE.

PRESS STEP TO WATCH METHOD LOOKUP AND OBJECT STATE.

st>
⌘/CTRL+ENTER evaluates · STEP sends one message · Classes and objects remain in this image
SENDS
STANDBY

MESSAGE TRACE STANDBY

STEP will identify the receiver, isolate its selector and arguments, walk the class hierarchy, and reveal any changed instance variables.

MESSAGE ENTRY UNIT

Numbers and syntax type directly; concept keys open their message cards.

SYNTAX OBJECT BLOCK COLLECTION
Smalltalk

EVERYTHING IS AN OBJECT.
EVERY ACTION A MESSAGE.

⟷

COMPUTATIONAL MACHINES · 06

ERLANG/86 PROCESS MACHINE

VM READY
0 PROCESSES · 0 MESSAGES
SHELL 06 · DETERMINISTIC SCHEDULERSPAWN → SEND → RECEIVE

ERLANG/86 PROCESS VM READY.

NO SHARED MEMORY. ONLY ISOLATED PROCESSES AND MESSAGES.

PRESS STEP TO WATCH THE SCHEDULER MOVE ONE EVENT.

1>
⌘/CTRL+ENTER evaluates · STEP advances one VM event · Process image persists until CLEAR VM
EVENTS
STANDBY

SCHEDULER TRACE STANDBY

STEP will reveal which process runs, which immutable term moves, how the mailbox changes, and which variables a pattern binds.

PROCESS ENTRY UNIT

Every key is implemented by this VM. Concept keys also open their reference card.

SYNTAX PROCESS PATTERN LIST
Erlang

LET IT CRASH.
SEND A MESSAGE.

⌶

VECTOR LOGIC SYSTEMS

APL/76 LEARNING TERMINAL

CORE READY
0 NAMES
SESSION 01 · ORIGIN 1RIGHT-TO-LEFT EVALUATION

APL/76 READY.

TYPE AN EXPRESSION OR LOAD AN EXAMPLE.

PRESS STEP TO WATCH EACH FUNCTION FIRE.

]
ENTER runs · STEP reveals one function · APL reads functions from right to left
TRACE
STANDBY

MICROTRACE STANDBY

STEP will isolate the rightmost function, display its arguments in their natural shape, and carry its result leftward.

GLYPH ENTRY UNIT

Every illuminated key is implemented. Select a key to read its function card.

MATH LOGIC ARRAY OPERATOR
APL

ONE SYMBOL.
ONE IDEA.