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Knowledge Base›MIT CADR›Uses of the Hyper modifier on the MIT CADR and LM-3

Uses of the Hyper modifier on the MIT CADR and LM-3

Bottom line

Hyper has no single system-wide meaning. Its strongest recurring application-level idea is “operate on a domain-specific structural unit”:

  • ZMail treats an address as a unit larger and more structured than a word;
  • C mode uses Hyper-. to find a C definition;
  • Inspector uses held Hyper plus left click to modify a field; and
  • Spacewar uses the physical Hyper switch for left rotation.

In the System 303 standard editor, however, Hyper is most often numeric-argument syntax or an alias-generation device. Many other subsystems preserve, strip, or discard it without assigning an action.

Evidence boundary and notation

The profiles and source pins are the same as in the companion Super catalog:

Profile Evidence
C46 Public System 46 source at Git 8e978d7d1704096a63edd4386a3b8326a2e584af
C303-SRC Maintained LM-3 System 303 source at Fossil 4df393c68d7f083ce42d5c377039d26043cc18a9031ace28258dc97f4137eb91
C303-RUN Explicitly recorded museum harness observations

H- means Hyper; combinations such as C-H-5 appear here because Hyper remains one of their constituent bits. “Hyper” in hyperlinks, HyperCard, hyper-pages, or Spacewar hyperspace is excluded unless it denotes the keyboard modifier.

Application summary

Application or substrate Hyper role Confidence
ZWEI/Zmacs command loop Numeric digits/minus; generated Hyper-letter compatibility aliases Complete selected-source algorithm
ZWEI C mode Hyper-. edits a C definition Selected source
ZMail draft editor Address-scale forward/backward/kill/exchange operations Selected source
Inspector Hold Hyper and left-click a settable field to modify it Selected source; runtime TODO
Spacewar Left Hyper turns the left ship left; Hyper also participates in the start gate System 46 source and runtime dossier
System key and TV menus Preserved or normalized modifier state without a general action Selected source
Supdup and Telnet No independent wire representation Selected source
EINE and System 46 standard ZWEI No standard Hyper editing row established Negative source result

ZWEI and Zmacs

Numeric arguments

System 303 installs digit ranges for every listed Hyper-bearing modifier family:

Family Effect
H-0 through H-9 Decimal numeric argument
C-H-0 through C-H-9 Same
M-H-0 through M-H-9 Same
C-M-H-0 through C-M-H-9 Same
Every corresponding family also containing Super Same

Minus is installed for the same families except for one strict source defect: C-H-- is absent even though C-H-0 through C-H-9 exist. The constructor spells C-- twice where the missing entry would be expected. This hole is part of the selected source profile.

Generated Hyper aliases

When System 303 constructs a named comtab, it generates compatibility aliases for uppercase letters under the seven Hyper-containing states:

H-C, H-M, H-S, H-C-M, H-C-S, H-M-S, H-C-M-S

Each candidate aliases the corresponding lowercase letter after removing Hyper, provided the source cell is still NIL. Lookup restarts at the original top comtab, so a local explicit binding, an explicit :UNDEFINED, or later parent resolution still matters.

This is not a semantic “Hyper version” of the destination command. It is a case/keyboard compatibility rule that often causes an otherwise unbound Hyper-letter chord to behave like the non-Hyper lowercase chord.

Special error text

The System 303 ZWEI command executor recognizes unbound Hyper-Space in its illegal-command message table and appends the joke:

Perhaps you should engage warp drive first.

This is an error-reporting special case, not a bound command.

ZWEI C mode

The C major mode installs:

Chord Command Effect
Hyper-. Edit C Definition Prompt for a C function, consult the C tag machinery, and edit its definition.

This is a domain-local analogue of definition navigation. It does not change the meaning of Hyper in Lisp, text, or mail modes. The named Read C Tags File command has no direct Hyper binding.

ZMail address editing

The ZMail mode comtab adds five commands:

Chord Command Structured unit
Hyper-F Forward Address Next address boundary
Hyper-B Backward Address Previous address boundary
Hyper-K Kill Address Address forward from point
Hyper-Rubout Backward Kill Address Address behind point
Hyper-T Exchange Addresses Adjacent address units

The grammar is intentionally parallel to Meta word editing, but the unit is a parsed mail address rather than a word. The same overlay is used by the relevant ZMail message/reply editing contexts. See ZMail keybindings.

Inspector

System 303 Inspector checks held modifier state rather than binding a distinct character in a comtab:

Hyper held + left click on a settable slot
└─ enter the direct slot-modification path

The field must advertise a setter or otherwise be marked modifiable. Inspector asks for the replacement by evaluated form or by pointing at another displayed value, then recomputes the inspected object display. The menu's Modify mode reaches the same family of operations without requiring Hyper.

This is a particularly strong Hyper semantic: it converts selection into mutation. The source and help text establish it, but the museum has not yet completed a live Hyper-left mutation probe. See Inspector.

Spacewar

Spacewar consumes the left physical Hyper switch as one game control:

Player Physical key Effect
Left ship FOO Left Hyper Turn left

The right ship instead uses Right Meta to turn left. Super turns both ships right. Shift—not Hyper—enters hyperspace. The naming coincidence is explicitly not the control mapping. Any of Control, Meta, Super, or Hyper starts play while the instructions are visible, so an otherwise unused Right Hyper can still dismiss the instructions.

System selection, menus, and pointer representation

Context Hyper behavior
C46 System prefix Modifier bits are preserved and require an exact registered chord.
C303 System prefix Hyper is stripped with all non-Control modifier bits; the base suffix is selected.
C303 Terminal prefix Exact modifier bits are preserved for registered suffixes.
Generic TV row menus Hyper is represented in the 32-state pointer space but normally does not change row selection.

The distinction between representation and assignment matters. A pointer event with Hyper is not equivalent at the character level to an unmodified event, even when a specific chooser normalizes both to the same row.

Supdup and Telnet

The selected terminal encoders have no independent Hyper representation. Control affects low character bits and Meta affects the transmitted high-bit convention; Super and Hyper do not acquire additional protocol bits. A compatibility implementation must reproduce that collapse rather than map Hyper to an invented escape sequence.

Negative and archival findings

  • EINE's audited table has no Hyper row.
  • The public System 46 standard ZWEI table does not establish a general Hyper command family.
  • No Hyper proceed-choice bank parallels the Error Handler's Super-letter bank.
  • System 303's Hyper-Space joke is not a command.
  • Reader examples such as Hyper-Meta-System or Hyper-Super-A prove character syntax, not a binding.
  • Inspector's Hyper-left is source/help established but still a runtime TODO.
  • The maintained tree's later bug archives mention experimental or site software; those records are not silently promoted into the selected System 303 load profile.

Interpretation

Hyper is best read as an application-reserved structural modifier. When an application has a meaningful unit not covered by character, word, or Lisp expression, Hyper is available for it: mail addresses, C definitions, inspectable slots, or a game-control switch. When no application claims it, the editor can reuse it for arguments and compatibility aliases.

Sources and verification

Last verified: 2026-07-26.

Try “search window system”, “open genera”, or “help”.