{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp12_substrate_denial72_20260805","cell_id":"context_keyed_representation_switching__computer_science","arm":"CONSTRAINED_HIGH","candidate_id":"context_keyed_representation_switching__computer_science__CONSTRAINED_HIGH","decision":"PROPOSAL","abstention_reason":null,"proposal":{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp12_substrate_denial72_20260805","cell_id":"context_keyed_representation_switching__computer_science","arm":"CONSTRAINED_HIGH","candidate_id":"context_keyed_representation_switching__computer_science__CONSTRAINED_HIGH","proposal_index":1,"version":0,"title":"Mechanically Keyed Passive Remapping Cassettes for Multi-Revision Board Debugging","problem":"A shared bed-of-nails debugging fixture must test recurring revisions of a computing board whose pad locations remain mechanically similar while their logical net assignments differ. A single compromise wiring map can connect an instrument to the wrong net, while manually reconstructing the fixture for every revision sacrifices reliable return to earlier revisions.","actors":["hardware verification engineer","computing-board revisions under test","shared bed-of-nails fixture","passive remapping cassettes","oscilloscope, logic analyzer, and stimulus instruments"],"observable_state":"The board presents a revision-specific tooling-hole or edge-notch geometry, and the fixture visibly exposes the identity of the installed cassette. With a matching pair, the board seats fully and the clamp closes; a mismatched or unknown geometry leaves the clamp physically blocked.","consequence":"Using the wrong pad-to-instrument correspondence can produce invalid diagnostic observations, conceal a hardware or firmware defect, or apply stimulus or voltage to an unintended net and damage the board or instrument.","affected_objective":"Integrity and electrical safety of repeatable measurements across recurring computing-board revisions.","intervention":"Use one shared bed-of-nails frame and invariant instrument connector panel with a bank of removable passive interposer cassettes. Each cassette contains fixed copper traces encoding one board revision's complete pad-to-instrument-port correspondence. Complementary mechanical keyways admit and clamp only the board geometry assigned to that cassette; removal opens the measurement circuit before another cassette can engage. Electrically isolated cassettes preserve inactive mappings without writable shared state, and an unknown board geometry cannot close the fixture.","structural_mapping":[{"archetype_element":"Shared Substrate Scope","domain_realization":"The common bed-of-nails frame, clamp, instrument panel, and invariant instrument-port meanings are reused across board revisions."},{"archetype_element":"Representation Portfolio","domain_realization":"A bounded set of passive copper-trace cassettes stores distinct pad-to-port mappings for named board revisions."},{"archetype_element":"Context Key Space and Cue Model","domain_realization":"Revision-specific tooling-hole or edge-notch geometry is the physical context key."},{"archetype_element":"Representation Selection Rule","domain_realization":"Complementary keyways permit full seating and electrical engagement only for the cassette and board geometry belonging to the same revision."},{"archetype_element":"Active Representation Indicator","domain_realization":"The installed cassette remains exposed through the fixture window with a molded identifier and a mechanically linked position flag."},{"archetype_element":"Inactive Representation Store and Isolation Boundary","domain_realization":"Removed cassettes retain their fixed traces independently and have no electrical contact with the active fixture."},{"archetype_element":"Switch Transition Guard","domain_realization":"An interlock opens all contacts before cassette release and blocks clamp closure until one cassette is fully latched."},{"archetype_element":"Re-Entry Integrity Test","domain_realization":"A passive continuity-and-isolation coupon matching each revision verifies its cassette after storage and after intervening use of other cassettes."},{"archetype_element":"Unknown-Context Fallback","domain_realization":"Unrecognized key geometry cannot seat or close the measurement contacts, leaving the instrument disconnected."}],"mechanism_mapping":[{"mechanism_slug":"context-to-map-routing-table","role":"Each cassette's fixed copper traces physically route the revision's test pads to invariant instrument ports.","counterfactual_removal":"Without distinct trace layouts, every revision would share one correspondence and incompatible logical-net assignments would be collapsed."},{"mechanism_slug":"context-tagged-namespace-partition","role":"Separate, electrically isolated cassettes embody disjoint revision-specific mappings on interchangeable parts of the shared fixture.","counterfactual_removal":"Without physical separation, modifying or shorting one mapping could contaminate the mappings needed for other revisions."},{"mechanism_slug":"active-map-status-indicator","role":"Cassette position mechanically exposes the identity of the mapping currently connected.","counterfactual_removal":"The passive routing would still work, but operators could not directly inspect which mapping is active; this mechanism supports observability rather than the essential effect."},{"mechanism_slug":"context-reinstatement-protocol","role":"Reinserting a previously used cassette reinstates its unchanged conductive correspondence without rebuilding it.","counterfactual_removal":"Returning to an earlier revision would require manual rewiring and would no longer preserve a persistent representation."},{"mechanism_slug":"map-difference-and-integrity-check","role":"Revision-specific continuity coupons test intended connections and unintended cross-connections without requiring analytical inference.","counterfactual_removal":"The fixture could still route signals, but latent trace or contact damage could defeat reliable re-entry without being directly detected."},{"mechanism_slug":"safe-default-map-fallback","role":"No keyed fit means no clamp closure and therefore an open measurement circuit rather than selection of a nearest known mapping.","counterfactual_removal":"An unknown or mismatched board could be forced onto a known map, recreating wrong-net contact."}],"causal_chain":["A board's tooling geometry supplies a physical context key.","Only the cassette with complementary geometry permits the board and cassette to seat and latch in the shared fixture.","Latching closes contacts through that cassette's fixed, revision-specific copper traces.","Those traces translate physical pad locations into stable instrument-port meanings without computation or inferred routing.","Removed cassettes remain electrically disconnected and retain their mappings while another cassette is active.","Reinsertion restores an earlier mapping; a continuity coupon can reveal loss of correspondence or isolation before a live board is connected."],"baseline":"A universal fixture is rewired from revision drawings or operated with manual pad-to-channel lookup tables. This makes the effective mapping dependent on reconstruction and interpretation at each switch and provides no intrinsic barrier against applying the map for one revision to another.","nearest_rivals":["A completely separate bed-of-nails fixture and instrument harness for every board revision, which provides strong isolation but duplicates the shared frame and connectors.","A programmable relay matrix that selects pad-to-port mappings from revision data, which is more easily updated but makes computation or software control essential to routing.","A manual patch panel with printed revision diagrams, which is physically flexible but relies on procedural accuracy and does not mechanically reject the wrong context.","Redesigning all board revisions to retain one permanent test-pad assignment, which removes the remapping problem but may be unavailable for existing or intentionally incompatible designs."],"remaining_contrastive_claim":"Relative to manual lookup or rewiring, the proposed fixture makes revision selection and pad-to-port remapping properties of complementary geometry and passive conductors themselves. Relative to separate fixtures, it preserves distinct, re-enterable mappings while sharing the frame and instrument interface. No claim is made about novelty or effect magnitude.","authority_safety":{"decision_authority":"The laboratory fixture owner may authorize a bounded prototype; electrical-safety and board-design owners retain authority over allowable test voltages and sacrificial hardware.","authorized_first_step":"Fabricate two unpowered low-voltage continuity coupons with different key geometries and two passive cassette prototypes for bench testing only.","excluded_actions":["connecting production or irreplaceable boards","applying power or active stimulus during the first test","defeating, filing, or forcing a mismatched mechanical key","treating molded labels alone as the context selector","adding software-controlled routing to compensate for failed physical discrimination"],"halt_rollback":"Stop if a mismatched coupon can close the clamp, if more than one cassette can contact simultaneously, or if any unintended conductive path is observed. Open the clamp, disconnect instruments, remove the prototype cassette, and return to the existing fixture without altering boards."},"negative_tests":{"strongest_counterevidence":"A mismatched or previously unseen board geometry can fully seat and reach any instrument contact, or activity and wear in one cassette measurably alter another cassette's stored correspondence.","problem_falsifier":"The board revisions do not actually require incompatible recurring pad-to-logical-net mappings, or maintaining one stable assignment across revisions is feasible without material loss.","intervention_falsifier":"Across repeated A-B-A cassette switches, the A coupon fails to recover its original complete continuity matrix, a wrong-key coupon closes any circuit, or contact resistance and crosstalk make the measurements unusable at the intended signal conditions.","risks":["Mechanical wear, debris, or manufacturing tolerance could weaken key discrimination.","A correctly keyed cassette could contain a fabrication error that faithfully routes the wrong net.","Contact resistance, added capacitance, or crosstalk could distort high-speed measurements.","Cassette identifiers could be swapped even though geometry still selects the electrical map.","Designers might reuse a key geometry after changing the logical mapping, creating an undetectable semantic collision.","Force applied to an unknown board could damage its pads or bypass the interlock."]},"next_evidence_step":"Build two small passive cassettes and four unpowered coupons: matching A and B coupons, an A-shaped coupon with deliberately permuted pads, and an unknown-key coupon. Using only a continuity meter and isolation measurement, test all cassette-coupon pairings, 100 A-B-A switch cycles, unintended cross-connections, contact resistance, and recovery of each original continuity matrix. The bounded test passes only if mismatched and unknown keys cannot close any measurement circuit and both mappings return unchanged after switching.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"Not assessed because runtime isolation forbids inspection of other proposals or experiment candidates.","revision_record":{"parent_version":null,"progress_targets_addressed":["Construct one causally defensible candidate under the binding substrate constraint.","Preserve persistent context-specific mappings, physical context selection, inactive-map isolation, guarded switching, and re-entry.","Specify rivals, safeguards, falsifiers, risks, and a bounded evidence step without novelty or effect-size claims."],"conceptual_changes":["Instantiated representation switching as passive electrical correspondence switching rather than software representation selection.","Made revision context physically legible through complementary board and cassette geometry."],"operational_changes":["Restricted the first step to unpowered continuity coupons and two cassette prototypes.","Defined mechanical and electrical stop conditions and reversible removal."],"evidence_changes":["Set an A-B-A switching test and exhaustive matching, mismatching, and unknown-key continuity matrix as the first evidence requirement."],"claim_changes":["Limited the contrastive claim to the causal difference between passive keyed routing, manual reconstruction, programmable routing, and duplicated fixtures."]},"substrate_contract":{"primary_allowed_process":"MEASUREMENT_INSTRUMENTATION","counterfactual_independence":"The essential effect is produced by mechanical fit discrimination, contact interlocking, and fixed conductive paths. If all software, algorithms, databases, dashboards, reports, incentives, authorizations, training, and procedural enforcement are removed, a matching board still connects through its cassette to the intended instrument ports, a mismatched or unknown key still cannot close the contacts, and inactive cassettes still retain their mappings.","forbidden_channel_audit":"No sensor output feeds analytics or a human decision to choose the map; the board geometry directly constrains engagement. No software or relay control determines routing. Labels, ownership rules, test records, and authorization are support wrappers only: removing them can reduce inspectability or safe deployment, but it does not remove the passive remapping, isolation, rejection, or re-entry effect."}}}