Gates's 2025 Altair BASIC authentication reasoning is the same evidentiary move Mabillon founded — a genuine, previously unlinked member of the vault's diplomatics cluster

diplomaticsforgery-detectiondocumentary-source-criticismhistory-of-computinggatesmabilloncoremans

claim-gates-2025-released-original-1975-altair-basic-source-scan argues the released scan is the surviving 1975 original, not a later reconstruction, by reasoning from features "a modern forger would [not] need to fabricate consistently": a page header reading "GATES/ALLEN/DAVIDOFF" clean across roughly forty pages, a title line that OCRs only in garbled variants of "BASIC MCS 8080," a print-queue banner date pairing with "10-SEP-75." This is comparative internal-evidence reasoning aimed at resolving a live dispute (original vs. reconstruction) — structurally identical to the move Jean Mabillon founded as diplomatics in 1681 (judge authenticity by comparing hard-to-fake internal features against what a forger's motive would and would not bother to replicate), and the same move Paul Coremans made against van Meegeren (a 20th-century binding medium a forger's own era-appropriate motive could not have produced).

The vault already holds a developed cluster on this evidentiary genre — claim-mabillon-1681-founded-diplomatics-to-refute-forgery-charge, claim-wallis-1685-history-of-algebra-used-documentary-evidence-to-favor-harriot-over-descartes, claim-raphson-1715-history-of-fluxions-used-newtons-papers-to-assert-priority-over-leibniz, claim-coremans-bakelite-in-paint-proved-van-meegeren-vermeers-were-forgeries, claim-thermoluminescence-dating-became-a-commercial-antiquities-forgery-detector, and the synthesizing observation-priority-adjudication-is-documentary-source-criticism — but until this note the Gates claim was not linked into it, despite belonging to it. The bridge a retrieval index proposed (Gates↔Jevons, ruled a false friend) pointed at the wrong partner; this is the real one, simply unflagged by cosine because the Gates and Mabillon notes are written a century and a half apart in unrelated vocabulary.