Lisp Machine Museum Documentation Examiner
Genera Museum Documentation
Knowledge Base›Color systems, the Genera Color Editor, and CADR color experiments

Color systems, the Genera Color Editor, and CADR color experiments

The Genera Color Editor is a component editor for live color objects, not a paint program and not a direct continuation of the MIT CADR's COLORHACK. It presents one or more three-slider color models, updates a large specimen pane, and either uses direct RGB drawing or temporarily manages an indexed color map. Its companion Color Palette selects, interpolates, organizes, and serializes libraries of color objects. The two tools are separate interfaces shipped by one experimental COLOR-EDITOR system.

The public CADR material represents an earlier and much smaller layer: a four-bit indexed framebuffer, sixteen mutable color-map entries, drawing primitives, and a set of laboratory or demonstration programs. Those programs are chronological and conceptual antecedents to later interactive color work, but no inspected source establishes that Genera's Color Editor descended from COLORHACK, COLXOR, or CAFE. This page keeps the lineages distinct.

The preserved Open Genera world did not yield a Color Editor window in the current isolated runtime. Its main X screen reported 24 useful bits per pixel, but no Color subsystem screen was registered, COLOR:EDIT-COLOR was not resident, and loading COLOR-EDITOR required the unavailable site file server. Thus a 24-bit host or X transport must not be mistaken for a configured Genera color workstation. The current visible presentation remained black and white, and this article does not substitute the monochrome fallback selector for the real Color Editor.

Evidence and release boundaries

Evidence set What it establishes Boundary
MIT CADR System 46 public source The distributed color-screen substrate, indexed map operations, raster drawing, and the transition away from the old COLOR-INKS cache. Git commit 8e978d7d1704096a63edd4386a3b8326a2e584af; the public tree contains no CAFE, COLXOR, or COLORHACK source.
LM-3 System 303 public Fossil source The maintained color library and the three color experiment files, plus their changing inclusion in HACKS. sys check-in 4df393c68d7f083ce42d5c377039d26043cc18a9031ace28258dc97f4137eb91; this is a restoration branch, not a 1980s release date.
Licensed Open Genera 2.0 / Genera 8.5 media COLOR 427.1, COLOR-EDITOR 421.0, Graphics Toolkit 23.0, implementation source, system directories, and the in-system Color documentation. Conclusions apply to the exact local media identified below. No licensed source, decoded Help, palette, or screenshot is tracked by this page.
Isolated Open Genera runtime The base world's screen depth, absent registered Color screen, absent resident editor entry point, and failed disconnected load. Session d33-color-systems-20260718, generation 1, 2026-07-18. It did not reach the application UI.

The Genera system declaration says that COLOR-EDITOR was created in the Symbolics Graphics Division in November 1983 and revised in December 1987 to include Graphics Toolkit. The main editor file records a February 1984 creation date. COLORHACK credits work from December 1982 and June 1983. Those dates establish overlap and sequence, not code ancestry.

Two ways pixels become colors

“Indexed” and “direct” describe how pixel data select displayed RGB values. They do not describe vector versus raster graphics; both systems discussed here ultimately draw pixels.

Model Pixel interpretation Consequence for an editor
Indexed or pseudocolor One pixel index selects a slot whose red, green, and blue values are stored in a color map. Genera's common eight-bit case has 256 possible indices. Changing a map slot can recolor every pixel carrying that index without rewriting the framebuffer. The editor must share, reserve, or temporarily replace scarce map slots.
Genera direct color A pixel supplies independent eight-bit red, green, and blue fields. Each field still passes through its corresponding map, normally initialized as an intensity ramp. Approximately 16.7 million RGB combinations are addressable. The editor can compute an RGB drawing ALU instead of allocating a private pseudocolor ramp.
CADR color TV A four-bit pixel indexes one of sixteen mutable RGB entries. Each entry has eight-bit red, green, and blue components. Geometry and apparent color are independent: animation can leave pixel indices fixed and alter only the sixteen-entry map.

Genera's protocol makes the distinction observable. A screen's :COLOR-MAP-DESCRIPTION returns :INDEPENDENT for a direct-color map and :DEPENDENT for pseudocolor. The Color Editor's :ASK mode uses exactly that third return value. The wider Color implementation also understands 8-, 12-, and 24-bit map modes, selectable map segments, and transparent or replacement overlays. Available combinations depend on the controller; these are software capabilities, not a claim that every Symbolics machine had every board.

The COLOR system is correspondingly much larger than the editor. Its serial build includes Graphics Support, common color-map and control protocols, allocation, machine-specific common code, general drawing, slave bitmaps, overlays, frame grabbers, controller drivers, commands, documentation, and synchronization programs. The declarations name CAD Buffer I and II, standard, high-resolution, chroma, low-resolution, VME, Univision, NuBus, NuVista, FrameThrower, and X modules. The small simple-color-map-mixin exposes only :8-BIT, a dependent map, and no overlay; the common layer supplies the broader abstraction.

Genera Color Editor architecture

COLOR-EDITOR is declared experimental, patchable, and source-distributed. It depends on the latest GRAPHICS-TOOLKIT and COLOR systems, then loads BASIC-SLIDER, COLOR-PALETTE, and COLOR-EDITOR in that order. The inspected system directory marks 421 as both released and latest. It was generated in Open Genera 2.0 on an 8-bit pseudocolor X screen, which is useful provenance but does not mean that the editor is resident in every distribution world.

The UI predates the Dynamic Windows application-frame style. Its COLOR-EDITOR flavor combines:

  • an editor state and constraint-layout mixin;
  • a virtual color map and color-map allocator;
  • TV:TEMPORARY-WINDOW-MIXIN, added because exposing an ordinary window could otherwise destroy the underlying color display;
  • a property list for interactive configuration;
  • a bordered constraint frame with a shared input/output buffer.

The frame contains one specimen pane, one command-menu pane, and nine reusable slider panes. A selected model consumes three sliders. The layout activates as many complete three-slider groups as fit; it does not expose a partial model. Resizing recomputes the slider capacity, and the constraint set is rebuilt from the active panes.

Entry points and return values

Entry Behavior in the inspected source
Load System Color-editor Loads Color Editor, Color Palette, Graphics Toolkit, and Color dependencies. This is a Command Processor form, not Lisp function syntax.
Edit Color Global Command Processor command; calls COLOR:EDIT-COLOR.
Select Color Global Command Processor command; calls COLOR-PALETTE:POP-UP-COLOR-PALETTE.
COLOR:EDIT-COLOR Reuses an existing editor window or creates one on a color screen. On success it returns the edited input object, a new color object, or NIL after Abort. If no color editor window can be made, it calls the black-and-white chooser.
COLOR:COLOR-EDITOR Function alias for COLOR:EDIT-COLOR.
COLOR-PALETTE:POP-UP-COLOR-PALETTE Finds or creates a color screen, preserves pointer and pan/zoom state, optionally forces zoom 2, and invokes the palette. It returns the selected color or NIL on cancellation.
COLOR:COLOR-DEMO then Edit Color Documented practice path that loads the editor, but does not give the caller the returned object.

When an input object is supplied, the editor duplicates it through RGB and commits RGB values back to that same object only on Done. Abort returns NIL without that commit. When no object is supplied, the inspected source constructs a new STANDARD-COLOR and initializes it to RGB (0.5, 0.5, 1.0), a light blue. This contradicts the chapter's claim that the initial specimen is the last color used. Runtime testing on a loaded 421 system is still required to determine whether a patch changed one side of that discrepancy.

The wrapper preserves the previous mouse sheet and location, color-screen pan and zoom, and—when using a private indexed map—the screen's prior map. Closing or deexposing the temporary editor injects an Abort event. No Save World or application file write occurs merely by editing a color.

How the sliders work

Each slider's left and right endpoints are recomputed by copying the current color, setting only that component to its minimum and maximum, and interpolating between the two. Other components therefore remain fixed while the background answers the question “what would this color look like across this component's range?”

Pressing any mouse button in a slider enters the same tracker. The implementation grabs the mouse, hides its blinker, maps horizontal position linearly into the component range, and clamps at the endpoints. While the button remains down it makes only low-cost updates; on release it performs the full redisplay and, for indexed mode, commits the managed map. The documented mouse line says L: move slider here, but the event method itself does not distinguish left, middle, and right.

There is no Color Editor application keymap. The top-level loop acts on structured mouse/menu events and ignores ordinary character input. Clicking the specimen pane with any button opens the System Menu; its mouse documentation is CLICK FOR SYSTEM MENU.

Color models exposed by this source

The Model dialog is built dynamically from the current value object's :LIST-COLOR-SPACES; each entry has independent Yes and No choices. With the default STANDARD-COLOR, the inspected flavor composition provides four models:

Model Sliders and source ranges Notes
RGB Red, Green, Blue; each 0.0–1.0 Normalized component values.
IHS Intensity 0.0–sqrt(3), Hue 0.0–1.0, Saturation 0.0–1.0 Hue is circular; the editor abbreviates Intensity and Saturation as Int and Sat when side labels are used.
Hexcone-IHS Hexcone Intensity, Hue, Saturation; each 0.0–1.0 Uses a different solid geometry from the trigonometric IHS conversion.
YIQ Y 0.0–1.0, I -0.60–0.60, Q -0.52–0.52 Represents luminance and two chrominance axes.

The common source also defines CMY conversion and a CMY mixin, but does not mix it into STANDARD-COLOR. It contains RGB/YUV conversion functions but no YUV object mixin in this file. The Color documentation says standard objects provide YUV as well. That is another release or patch disagreement to test rather than resolve by guesswork.

Complete Color Editor menu and configuration surface

Main item Effect
Done Commit RGB to the supplied object, or return the new value object; close the edit.
Model Open Choose Models, rebuild active three-slider groups, and redraw. Multiple models may be active simultaneously.
Config Open Select Configuration with every option listed below.
Abort Return NIL without committing to the supplied object.
Config field Exact choices Default and implementation effect
Display Size Small .2; Medium .3; Large .4 Medium; fraction of the frame assigned to the specimen pane.
Numeric Redisplay Mode Continuous; Incremental Incremental; continuous updates while tracking, incremental updates at the full release-time redisplay.
Numeric Display? Yes; No No. Turning it on forces side labels off; turning it off forces side labels on.
Number of Color Segments 20, 40, 60, 100 60; a direct-color ramp is drawn with this many sections, bounded also by pane width. In indexed mode, available map slots and active panes determine the effective count.
Color Mode Use Standard Palette; Use best; Use color map Source values are T, :ASK, and NIL. :ASK chooses direct drawing only for an independent map; NIL allocates a private indexed map.

The manual describes a separate Side Labels? choice. In COLOR-EDITOR.LISP.72 that row is commented out, while the numeric-display setting forcibly selects the opposite label layout. This page reports the source-visible 421 surface; the documented extra row remains a runtime TODO.

Direct versus indexed rendering inside the editor

In direct mode, the specimen pane converts the current RGB values into an RGB ALU, and every slider ramp computes its segment colors the same way. In indexed mode, the editor creates a virtual map with one object per hardware slot. Slot zero is left outside its default allocation, the final slot is initialized white and likewise excluded, and the specimen pane claims one required slot beginning at slot one. The remaining slots are divided among active slider bars, limited by the requested segment count and each pane's pixel width.

The indexed path explains two visible effects described in the manual: ramps may have fewer than the requested 60 colors, and taking over a pseudocolor map can make other simultaneously visible indexed images change appearance. The editor restores its saved map when the edit unwinds.

Genera Color Palette

The Color Palette is the persistent-selection side of the system. A page is 48 chips—four rows of twelve—with a selected-color specimen, function boxes, and page selectors. Its initial rows are:

  1. grays from black to white;
  2. bright saturated hues around the color wheel;
  3. darkened versions of those hues;
  4. desaturated versions of those hues.

The implementation represents a palette as a Graphics Toolkit ROW-DATABASE with row length 12, and the collection of named palettes as a LIST-DATABASE. An empty chip is NIL, displayed by the legacy layout as a small point rather than as a white color.

Complete chip and row gestures

Gesture over a chip Filled chip Empty chip
Left Copy that chip into the selected-color box. If the palette is short-lived, also exit with it. Copy the selected color into that slot.
Middle Recompute the entire row as an interpolation from its first to its last chip. Fill the gap bounded by the nearest nonempty chips to the left and right.
Right Delete the chip. Leave it empty.
Shift-left Replace the row with the next of the four initial row sets: grays, bright colors, dark colors, desaturated colors. Same row operation.
Shift-middle Repeat the last row-menu operation on this row. Same row operation.
Shift-right Open the row menu listed below. Same row operation.

Interpolation is not a naive component-by-component RGB ramp. RINGLESS-INTERP first interpolates RGB, then independently interpolates intensity and writes that intensity back. The source says this avoids the dark band that ordinary RGB interpolation can produce in a round brush.

The full-row implementation has an unresolved arithmetic anomaly: for twelve slots it rewrites slots 1 through 11 using a divisor of 10, so the final interpolation factor is 1.1 rather than 1.0. The intended endpoint behavior described by the manual must be checked in the running release before treating this as a visible bug.

The Shift-right row menu is complete in the inspected source:

Row command Operation
Delete Row Replace all twelve cells with NIL.
Reverse Row Reverse chip order.
Shift Row Rotate the row one position to the right.
Desat Row Subtract 0.05 from each chip's hexcone saturation.
Saturate Row Add 0.05 to each chip's hexcone saturation.
Lighten Row Add 0.05 to each chip's hexcone intensity.
Darken Row Subtract 0.05 from each chip's hexcone intensity.

The page source uses the special characters MOUSE-L-2 and MOUSE-R-2 for the shifted left and shifted right gestures; Genera's mouse documentation maps those characters to sh-L and sh-R. They are not additional undocumented commands.

Complete function-box and page surface

Function box Effect
Exit Return the selected color. With an input object, write the selected RGB values into it.
Rows Choose Grays, Colors, Dark Colors, Desat Colors, or Delete, then choose Row 1, 2, 3, or 4.
Edit Invoke COLOR:EDIT-COLOR on the selected color and replace the selection with a successful result.
Libr Open the library menu below.
Abort Return NIL; the wrapper restores the original input object's RGB values if necessary.
Library item Effect
Select Make another in-memory named palette current.
New Library Create an empty palette, prompt for a name, register it, and select it.
Make Copy Copy the current palette, prompt for a name, register it, and select it.
Delete from Memory Select and confirm removal of an in-memory palette.
Erase Current Library Confirm, then remove every page and row from the current palette.
Save to File Select one or more libraries, choose a Graphics Toolkit project, and serialize each selected object.
Read from File Choose a project and one or more palette object files, then load them into the object registry.

An Append implementation remains in GENERAL-SAVING-MENUS, but its menu entry is commented out. It is not part of the current user-facing list.

The selector column contains the current page number plus 1, -, and +. 1 returns to the first page. Left on - or + moves one page, middle moves one row, and right moves five pages. Palette top-level character input is not a command surface: ordinary characters beep. Text entry is meaningful only in the name, project, and file-choice dialogs.

What a saved palette file is

A saved palette is neither a bitmap nor a plain RGB table. Each PAINT-COLOR has a FASD reconstruction form containing red, green, and blue initialization values. The Graphics Toolkit external-object machinery walks a selected palette, resolves its project, and calls SYS:DUMP-FORMS-TO-FILE on a form that adds the reconstructed object to its class library. Loading resolves an external tag to the project's palette subdirectory with canonical type IBIN and evaluates the dumped form.

This is therefore a Genera serialized object/form file with executable load semantics. It is meaningful inside the corresponding Graphics Toolkit and class environment, but it is not an interchange palette comparable to GPL, ACT, or a raw RGB file. A preservation converter should parse it inertly and emit explicit rows, slots, RGB triples, names, and source provenance rather than loading untrusted serialized forms.

The manual's older workflow says that Save to File prompts for a pathname. The inspected Graphics Toolkit source instead chooses a registered project and resolves its palette subdirectory. This source/manual difference also needs runtime 421 verification.

One source boundary matters for visual reconstruction: the current COLOR-PALETTE.LISP.56 marks its old layout object, window resource, and item construction methods as disabled until a newer Paint version is installed. The active behavior methods and manual establish the operations, but the exact pixel layout can depend on definitions supplied by Paint. It should be captured from a running 421 configuration rather than reconstructed from the disabled block alone.

MIT CADR color substrate

System 46's active LMWIN; COLOR 33 defines a 576-by-454 COLOR-SCREEN with four bits per pixel. Because the source uses octal notation, map sizes 20 and final index 17 mean decimal 16 and 15; component maximum 377 means decimal 255. The screen stores indices, while a 16-by-3 ART-8B array mirrors the hardware RGB map.

At warm initialization the code probes the color controller. Only a successful probe programs synchronization, installs the Color Window System Menu entry, and permits exposure of the screen. A failed probe removes that entry. The library provides:

  • synchronized and immediate map writes, whole-map transfer, map reads, fills, primary, spectrum, grayscale, and random maps;
  • bars, stripes, crosshatches, rectangles, points, lines, characters, and strings;
  • map-only animations such as random flashing and gradual exchanges;
  • a COLOR-SCREEN font conversion path for ordinary one-bit fonts.

The active System 46 implementation uses one refillable 8-by-1 four-bit array as a solid BITBLT source. The older LMIO; COLOR 69 instead cached sixteen 8-by-8 arrays under the misleadingly broad name COLOR-INKS. They are implementation tiles, not a palette or authored art. The dedicated color inks and raster patterns article documents that transition and the separate monochrome gray/stipple system.

System 303 WINDOW; COLOR 70 retains the indexed screen and map, uses TV:STANDARD-SCREEN, initializes the primary map when hardware is present, and documents Color Window in the System Menu. It adds RECTANGLE as the preferred width-and-height API while retaining endpoint-based COLOR-BITBLT as obsolete compatibility.

There is no high-level color object, selectable model set, named palette library, or file format in this CADR layer. Apparent colors are mutable hardware state; a saved four-bit framebuffer alone cannot reproduce its appearance without the matching map.

CADR experiments: three distinct programs

The three experiment files survive in the LM-3 restoration tree but not in the public System 46 snapshot. SYSDECL.LISP.198 included all three in HACKS; SYSDECL.LISP.200 comments them out with “leave out color stuff.” Their source still exists, and COLXOR still contains a DEFDEMO registration, but the pinned System 303 HACKS build does not load them by default.

COLORHACK: library and two small interactive mixers

COLORHACK.LISP.8 is primarily a library. Its function named COLORHACK contains only a documentation string; calling it does not launch an application. A user must load the file and call USE-COLOR-SCREEN, which caches screen geometry and creates an RGB counter window and a color-screen mixer window.

Its feature surface is:

  • named RGB triples for black, white, red, green, blue, lime, cyan, and violet;
  • single-slot get/set, whole-map read/write/print, black, random, linearly shaded, interactive-definition, melt, and wandering-map operations;
  • direct pixel, clipped pixel, line, clipped line, character, string, outline circle, filled circle, and overlapping-primary-circle drawing;
  • DEFINE-COLOR, which edits one map slot while an ordinary window displays its red, green, and blue values in octal;
  • MIX-COLOR, which displays overlapping red, green, and blue circles and edits the seven nonempty combinations.

For both interactive mixers, hold left to increase red, middle to increase green, and right to increase blue. Double-clicking and holding changes the sign and decreases that component. Any keyboard input terminates the mixer and returns an RGB list. There are no menus and no palette-file commands.

Source inspection exposes a preservation defect: READ-MAP terminates when the loop variable equals *LAST-COLOR*, so it copies indices 0 through 14 but not index 15. WITHOUT-CLOBBERING-MAP consequently cannot be assumed to preserve the final slot unless it was already valid in the save array.

COLXOR: geometry plus color-map motion

COLXOR.LISP.55 increments four-bit pixel indices while symmetric line and wedge routines build patterns. The visible motion then comes mainly from cycling or perturbing map entries. This cleanly demonstrates the separation between indexed geometry and its current colors.

If the file is loaded with the demo framework available, Color TV Hacks contains:

Demo Operation and termination
Smoking Clover Clear the color screen, install a random map, draw Gosper's symmetric wedge pattern, then animate the map through COLOR-GUARD; any pending terminal input stops the animation.
Cafe Slide Run the separate cafe-wall illusion below; the menu documentation asks for Space to begin.
Color Mash Perturb successive map entries; any pending terminal input stops it.
Color March Shift changing RGB values down the map; any pending terminal input stops it.
Random Ramp Fill the sixteen entries once with bounded random RGB values; finite operation.
Brighten Install a finite red/green/blue intensity arrangement intended to make the display more visible.

COLOR-RAMP is present in source but its demo entry is commented out as unable to work. The guarded top-level demonstrations notify the user when the color hardware probe fails instead of writing blindly to absent hardware.

CAFE: map-animated cafe-wall illusion

CAFE.LISP.9 is not a color editor. Its unmarked integer constant 22 is octal in this Base-8 file, so it draws an 18-by-18 cafe-wall pattern, not 22 by 22, with a spacer one-sixteenth of a row high. CCH assigns black, white, and middle gray to three map entries for a static illusion; CCHC sinusoidally exchanges the first two gray levels.

CAFE-SLIDE draws a finer striped checker. Each row starts with one stripe in background index 0; subsequent stripes cycle dynamic indices 1 through 14 on even rows and use them in reverse order on odd rows; index 15 is the spacer. Source comments call the dynamic range 1 through 16, but the Base-8 code bounds are octal 1 through 16. It waits for one character before animation; the demo menu calls that character Space, but the function accepts any character. It then repeatedly sweeps map entries in opposite gray directions. A later :TYI-NO-HANG exit test is commented out, so there is no application-level stop key after motion begins; process or Abort control is required.

Revision 9 changed its fill call from endpoint-based COLOR-BITBLT to width-and-height COLOR:RECTANGLE without changing endpoint-shaped arguments. Static inspection therefore suggests oversized or clipped rectangles, but only a color-TV runtime can establish the visible result. It remains an explicit TODO, not a claimed historical behavior.

Runtime observation and screenshot boundary

The Genera probe used the isolated Genera Xvfb harness. The relevant ordered actions were:

  1. An overlong combined probe timed out during host typing and was never evaluated; the stuck key was released and the input was cleared.
  2. (list (send tv:main-screen :bits-per-pixel) (send tv:main-screen :useful-bits-per-pixel)) returned (24 24).
  3. A guarded call to COLOR:FIND-COLOR-SCREEN with :CREATE-P NIL, :ERROR-P NIL, and :WHICH :ALL returned NIL.
  4. A probe for the unsupported :COLOR-P message entered the error handler. In its evaluator, (fboundp (quote color:edit-color)) returned NIL; Control-Z then returned to the listener top level.
  5. Load System Color Editor was rejected because the parser treated Editor as an extra keyword. After clearing that input, the documented token Load System COLOR-EDITOR treated the name as an unknown system and tried to read DIS-SYS-HOST:>sys>site>color-editor.system.newest, producing a site-login prompt. Control-Z and Abort returned to the listener.
Runtime item Portable record
Session d33-color-systems-20260718, generation 1; action log 34 records, SHA-256 7a07192271f9597037dc7cbb134c1f4d2998e2a1910bcdc6a00c531daafdb86b
World Genera-8-5.vlod, 54,804,480 bytes, SHA-256 a8ee5e86cc7e322f7385af3e0cd579d7650d4dcfc3ce328acbf8b25515dd0672
VLM genera, 1,533,760 bytes, SHA-256 9f5e18d5770f973879716182b6856ef5a8ee9d3b2bb907476ea0cf35986aa4c7
Debugger VLM_debugger, 346,880 bytes, SHA-256 2db918cfe8f35f52c7ff4b7695b0ecd3bb85e41a3327ea5a94874edf05edb54a
Compatibility inputs X preload acd71dbcb948f05b7fd2730b2b4706c08f16f46d792bd9aa6aa64370e855e4b1; ifconfig preload f45f45461622975996ab41138f64bb84a4b17c51fba0dbb649208914898c26b7; RFC 868 responder cc3a2274149c5593b52e6608d732d4048518c766134df5e0f018746ad5cf98bb; config 5ce6509f5adf2cf2d054d34eb4ba777ce462285b8cd9b01bc071bf819139e086
Execution envelope Bubblewrap user, mount, network, PID, IPC, and hostname isolation; private tun0 without an external route or host file service; Xvfb 1440x1100x24 with MIT-SHM verified absent. Main Genera client 1200x900, title Genera on DIS-LOCAL-HOST.
Toolchain Guix manifest SHA-256 3adae999bbe420182f22adc2499fcc82449a46eaf580a362de9c0e718fa6b37d, channel commit 230aa373f315f247852ee07dff34146e9b480aec; CPython 3.11.14.
Shutdown Prompt observed, yes sent and accepted, cleanup progress observed, then bounded force after the known VLM cleanup stall. forced_stop and state_may_be_incomplete are true. Base and private world hashes remained unchanged. Save World and guest checkpoint status remain unknown; the harness created no host-process checkpoint.

Raw 1200-by-900 evidence captures remain ignored in the session tree. The depth result capture has PNG SHA-256 7a9d178d183dca460ec52a75142f456bf2529c259ba4b50c16a8bebb393a16a0 and pixel SHA-256 87b8d0de2b0b798895562cffac020214bbfed41191200c9fc80c7b0b9488ff15; the no-color-screen result has PNG SHA-256 84d1f6a1b9862699a184c241c219c99690fc84557fafa3924a037b0617cd8b5a and pixel SHA-256 ab72fc1b2370812735fd975335941a97fd4fb30319944b0860453dcd856de44a; the disconnected load result has PNG SHA-256 4572a540d1367a8344b7bae11c89efdbca874ebd1d71420eb356c18ee404480d and pixel SHA-256 9288d7770d27f91a64d3f9522be30a7bc735935d268ff6984c685792189e9449.

No screenshot is published here. None of those captures shows the Color Editor or Color Palette, so a listener/error screenshot would be misleading evidence for the visible application and would not justify an additional copyrighted image. A representative application capture remains blocked until the licensed subsystem can be loaded locally and a real Color screen reached; any selected image must then pass the repository's image-specific publication review.

No new CADR runtime was claimed. The standard CADR harness does not expose the maintained emulator's optional -a color-TV launch path, and the pinned System 303 HACKS declaration excludes the three source files. A defensible runtime test must add a provenance-recorded color display path, load the exact files without changing the public originals, and capture both the ordinary and color clients. Until then, the CADR sections above are source analysis, not observed output.

Preservation record

The licensed source and documentation were inspected in place and remain untracked. Logical or media-relative names are used here instead of host paths.

Licensed Genera artifact Bytes SHA-256
opengenera2.tar.bz2 206,213,430 89fb3e76b91d612834f565834dea950b603acf8f9dbacacdd0b1c3c284a2d36e
Genera-8-5.vlod 54,804,480 a8ee5e86cc7e322f7385af3e0cd579d7650d4dcfc3ce328acbf8b25515dd0672
color/color-editor/sysdcl.lisp.~6~ 3,675 aaee69416e5d31227d266f9ce84b0e83b9fcbceded4f5a8ca344434b38d7148c
color/color-editor/basic-slider.lisp.~25~ 12,277 6d2483159997886f3f2e114bcfe308b96665f82d2cee7661fd48594d92f89eab
color/color-editor/color-palette.lisp.~56~ 35,160 f38a06dcbcf33c2db658cc0ca2682d3793c7002d788cd991791a8295f07b5811
color/color-editor/color-editor.lisp.~72~ 33,236 9717a8628f9ed5af6de7b7aac1b4fa021d4df350cc82ac7ba353d045e2070450
color/color-editor/color-editor.system-dir.~99~ 2,082 2c68fb32430a5c2f1eae3477df93c4714a300e2f68159caea9b1f66ff94b5ed4
window/colors.lisp.~23~ 41,944 5978600d367b50c87134e4f86ddda6bba2f25471251ee02802b0ac474d9aa5e2
color/sysdcl.lisp.~115~ 8,315 3d83babdace0a33566a0a3ca26d1b2730b9f5993975198dfc718d071bd9d1d89
color/common-color.lisp.~621~ 93,090 703e11ecdad7087fe2812c4d352ff7fbb3a0c55533728bb4f5e8c1a507aa93c1
color/simple-color-hardware.lisp.~174~ 26,903 1b9ff835d8bf6d0d01af465fb7d0da24f845b6c950404572e02fd9f1b7c57031
color/color.system-dir.~176~ 3,823 63a7a19887fd5bbc68c48697db62c09cf13c12cefadc4fe9a2143f49c675f52e
color/graphics-toolkit/menu-items.lisp.~225~ 143,924 077dca8895731f6ea2e04a27df97d9efc69e7c014b17b19b5e7c02cdc7327265
color/graphics-toolkit/database.lisp.~59~ 25,155 d0df4feccdb961a2af717e39815a215ade82544cd160e0a27ab1edee5cf01d85
color/doc/color-ch7-editing-colors-interactively.sab.~21~ 32,636 b4d3dd1fade92f60035ab28631a3356bbfa18a3d10333dd6b84e7ac3730e4340

The chapter is Sage Binary format 7 with 12 records. It was decoded only under the ignored Help tree using the tracked inert extractor described in recovering Genera on-line documentation. No decoded vendor prose is linked or committed here.

System 46 source observations use the public repository at commit 8e978d7d1704096a63edd4386a3b8326a2e584af:

Public System 46 artifact Bytes SHA-256
src/lmio/color.69 20,844 7cb1cab3b96a031dc9ba83765b8b5cc285cc9e1e8a528ca828f8680cdb813cc2
src/lmwin/color.33 27,200 d9d12f0cb03a1d24b2d35fe80aa9ac20846cfb701b07ab04360606ab80fa782e
src/lmwin/color.qfasl 24,416 5ca940ec55dfa2ac03c04b6a9458c054e63363beced30fcb16ff574292238294

LM-3 observations use sys check-in 4df393c68d7f083ce42d5c377039d26043cc18a9031ace28258dc97f4137eb91. The audited private source copy recorded public revision 4df393c68d7f083ce42d5c377039d26043cc18a9031ace28258dc97f4137eb91 and tree SHA-256 21f5215de973aa6ccbddb817f2d64edd95ee1014c3028a9b0711ea7c741b807e at copy and execution start.

Public LM-3 artifact Bytes SHA-256
window/color.lisp.70 32,431 38e577c94d4ff73e92a48d8368aecb5298f33112bb57421e579168a97b674d62
demo/colorhack.lisp.8 26,219 3bac643b508464c3e31e5524982efe0410b3fcea09c2975e3750e0a98166d33c
demo/colxor.lisp.55 13,394 839135407e86b10091694ec0cd52d46dcace47aa75fdd974f7514b2e74e05707
demo/cafe.lisp.9 6,064 3794600d089d148640c48c95a3bb806bc09188eb3fbbde4f3770d8dc13c1f0a2
sys/sysdcl.lisp.198 20,014 dae699d297c2be588adeb1a5ce1f14a197623ca64e963f335a436327280a1255
sys/sysdcl.lisp.200 25,396 2999f1824666171d729dae611a09204ac0bd42373f30d7d22c733f904c27a6dd

Preservation implications

  • Preserve an indexed framebuffer together with its active map and map mode. Pixel values alone do not preserve displayed colors or map-animation timing.
  • Record whether a Genera capture used a dependent or independent map, the segment number, overlays, and any map allocation made by the application.
  • Treat Genera IBIN palette libraries as serialized executable objects. An extractor should decode forms inertly, retain names and empty slots, and never require loading licensed or untrusted content into a live world.
  • Do not reconstruct the Color Palette layout from the disabled source block as if it were proven runtime geometry. Capture the definitions actually supplied by the paired Paint and Graphics Toolkit versions.
  • Keep the CADR experiments separate from the Color Editor in catalogs. A shared color map and similar mouse-controlled RGB idea do not establish one program or one source lineage.
  • Preserve octal notation when transcribing CADR values or translate it explicitly; otherwise 16-entry arrays and 255-level components are easily misreported as 20 and 377 decimal.

Open questions and runtime TODOs

  • Provide the isolated Genera guest with a read-only, provenance-pinned local source service sufficient to load COLOR-EDITOR 421 and its exact dependencies, without exposing the purchased tree or creating a general host file service.
  • Determine whether FIND-COLOR-SCREEN :CREATE-P T can construct a usable Color screen on the Open Genera X client once the system is loaded. The current result with :CREATE-P NIL proves only that none was registered.
  • Capture and review one Color Editor state and one Color Palette state, including Model, Config, row, and library menus, then resolve the “last color,” Side Labels, YUV, and disabled-layout source/manual discrepancies against runtime 421.
  • Extend the CADR harness with the pinned usim optional color-TV path and provenance for both X clients; manually load the excluded demo files in a fresh private disk.
  • Test CAFE-SLIDE geometry and termination, COLORHACK's final-slot restore, and the exact visible map behavior. Publish only the minimum reviewed screenshots needed to support those findings.
  • Search earlier Symbolics source history, if lawfully available, for direct reuse or attribution between the MIT experiments and the 1983–1984 Color Editor. Until such evidence appears, their relationship remains contextual rather than genetic.
  • Document the physical monitor, phosphor, transfer, and calibration assumptions behind the CADR's nominal eight-bit RGB map values.

Sources

Last verified: 2026-07-18.

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