---
id: "20260912-0223-do-an-wangs-1949"
title: "Do An Wang's 1949 and Jay Forrester's 1951 core-memory patent filing dates hold up against the patents themselves or a peer-reviewed history?"
type: "capture"
status: "promoted"
origin: "batch"
promoted_to: ["30-notes/claim-wang-forrester-patent-records-confirm-1949-1951-filing-gap.md","30-notes/claim-rajchman-rival-filing-forced-legal-contest-over-forresters-inventor-status.md","40-entities/entity-jan-rajchman.md"]
not_promoted: ["Capture's claims 1-3 (Wang's 1949 filing confirmed; Forrester's 1951 filing confirmed; the sequence holds up) merged into a single atomic note rather than split three ways — all three verify the same filing-date gap and would always be cited together. See claim-wang-forrester-patent-records-confirm-1949-1951-filing-gap.md.","Further leads not read directly this session, left unpromoted: Frederick Viehe's 1947 patent, Jan Rajchman's own exact filing date/patent number, Emerson Pugh's 1984 IEEE Transactions on Magnetics paper, and An Wang's autobiography. Tracked at question-verify-core-memory-patent-filing-dates-primary-sources.","Entity candidates Frederick Viehe, Emerson Pugh, and Research Corporation tested against entity-page-spec-v0.1.md and not promoted: Viehe and Pugh are named leads with no new substantiation this session to hang a hub on (unsure -> don't promote); Research Corporation is load-bearing within only this single cluster, failing the stricter org-promotion bar (acts within one cluster only, per the spec's org test)."]
writer_model: "claude-sonnet-5"
date_created: "2026-09-12T00:00:00.000Z"
provenance: "Direct topic research against 00-meta/specs/sources.md sourcing floor, 2026-09-12"
derived_from: []
tags: ["computing-history","patent-history","jay-forrester","an-wang","cold-war-science","attribution-myth","quote-verification"]
verifies: "question-verify-core-memory-patent-filing-dates-primary-sources"
source_url: "https://patents.google.com/patent/US2708722A/en"
source_title: "Pulse transfer controlling device (US2708722A)"
source_author: "Wang An [An Wang]"
source_date: "1949-10-21"
source_venue: "U.S. Patent Office, via Google Patents (house-convention primary-document mirror for reproduced grant text)"
source_tier: 1
source_sha: "a2702d4d2c8c06c64520537c083400b865489676c255f4285451d051bfb8df23"
source_quote: "Filing date1949-10-21Publication date1955-05-17"
source_url_2: "https://patents.google.com/patent/US2736880A/en"
source_title_2: "Multicoordinate digital information storage device (US2736880A)"
source_author_2: "Jay W Forrester"
source_date_2: "1951-05-11"
source_venue_2: "U.S. Patent Office, via Google Patents (house-convention primary-document mirror)"
source_tier_2: 1
source_sha_2: "ac4e8edef7ed0c29750a6ad4a1874b13f548cc3cbc15d5f28e94078fa6d437c9"
source_quote_2: "Filing date1951-05-11Publication date1956-02-28"
source_url_3: "https://cdn.libraries.mit.edu/dissemination/diponline/AC0069_NewReleases/NewsRelease_1960/AC0069_1964/AC0069_196404_015.pdf"
source_title_3: "Background on Forrester Computer Memory"
source_author_3: "MIT Office of Public Relations (unsigned institutional press release)"
source_date_3: "1964-04-14"
source_venue_3: "MIT Institute Archives & Special Collections, News Office (AC0069)"
source_tier_3: 1
source_sha_3: "e2359aabe90a20a75e67f02ca92597ff3784acfe68b269bba2630d45e4e5e535"
source_quote_3: "Forrester's patent was obtained in 1956, but his inventorship was contested in the Patent Office by Dr. Jan A. Rajchman, a researcher in the employ of Radio Corporation of America, who had filed in the Patent Office a patent application describing a form of magnetic memory system."
source_delight_3: "MIT's own 1964 press office statement narrates, in one paragraph, that a rival's earlier-filed patent application had to be defeated in federal court before Forrester's 'inventor' status became official."
source_url_4: "https://www.tomshardware.com/tech-industry/jay-forrester-filed-the-first-practical-ram-patent-75-years-ago-this-week"
source_title_4: "Jay Forrester filed the first practical computer RAM patent 75 years ago this week — his Magnetic Core Memory patent would be granted five years later"
source_author_4: "Luke James"
source_date_4: "2026-05-17"
source_venue_4: "Tom's Hardware"
source_tier_4: 3
source_sha_4: "7f3b31bb76fed7341487a7957805996867454a57117097f250629b91d11ca798"
source_quote_4: "RCA engineer Jan Rajchman had filed a similar application eight months earlier"
seek_code_commit: "850b81d"
---


This capture follows up [[question-verify-core-memory-patent-filing-dates-primary-sources]], which flagged [[claim-an-wang-1949-patent-filing-predates-forresters-1951-core-memory-patent]] as resting on a single Tier 3 Computer History Museum web page for a specific sequence of patent-filing years. Both named patents were located and read directly via patents.google.com (this vault's established reachable mirror for reproduced USPTO grant text, per `sources.md`'s known-blocked-routes notes — direct USPTO endpoints 403/404 without an authenticated session).

## Claim: An Wang's core-memory patent record confirms a 1949 filing date
verifies: question-verify-core-memory-patent-filing-dates-primary-sources

[[entity-an-wang|An Wang]]'s patent "Pulse transfer controlling device" (US2708722A, application US122769A) carries a filing (and priority) date of 1949-10-21 in the patent record itself: "Filing date1949-10-21Publication date1955-05-17." The patent issued 1955-05-17 and is listed as expired-lifetime (anticipated expiration 1972-05-17, the standard 17-year term from grant). This is a quantitative (date) claim resting on the primary document itself — Tier 1 — not on the museum web page the earlier claim-note flagged.

## Claim: Jay Forrester's core-memory patent record confirms a 1951 filing date
verifies: question-verify-core-memory-patent-filing-dates-primary-sources

[[entity-jay-forrester|Jay Forrester]]'s patent "Multicoordinate digital information storage device" (US2736880A, application US225714A, assigned to Research Corp) carries a filing date of 1951-05-11: "Filing date1951-05-11Publication date1956-02-28." The patent issued 1956-02-28. Tier 1, read directly from the primary document.

## Claim: The Wang-precedes-Forrester filing sequence holds up against the patents themselves
verifies: question-verify-core-memory-patent-filing-dates-primary-sources

Reading both patents directly confirms the specific two-year gap the flagged claim-note had sourced only to an unsigned Computer History Museum page: Wang's application was filed 1949-10-21 and Forrester's 1951-05-11 — a gap of roughly 19 months, consistent with the museum page's "1949" vs. "1951" framing. On this narrow, load-bearing question — do the two headline filing dates themselves check out against the patent record — the answer is yes. This resolves the `[unverified-quant]` flag on [[claim-an-wang-1949-patent-filing-predates-forresters-1951-core-memory-patent]] for the Wang/Forrester pair specifically (the Viehe-1947 and Rajchman-1950 legs of that same four-name sequence were not independently re-verified against their own patent records this session — see Further leads).

## Claim: Filing-date order is not the same thing as legally recognized priority of invention
An MIT Office of Public Relations background statement, issued 1964-04-14 (contemporaneous with the settlement it describes), records that Forrester's patent — though granted in 1956 — had its inventorship "contested in the Patent Office by Dr. Jan A. Rajchman," an RCA researcher whose own core-memory patent application predated Forrester's: Tom's Hardware, drawing on the same dispute, describes Rajchman as having "filed a similar application eight months earlier." The contest ran through the Patent Office and then the U.S. District Court in New York; per the MIT statement, a 1964 consent judgment was needed before "Forrester's position as inventor of the coincident-current core memory was established," accompanied by an IBM-to-MIT settlement the document puts at "$13, 000, 000" (a round $13 million). This complicates a purely date-sequence reading of "who invented core memory first": Forrester's filing date (1951) trails Rajchman's, yet Forrester — not Rajchman — ended up as the legally recognized inventor of record for the coincident-current system, by litigation outcome rather than filing priority alone. Wang's 1949 patent, by contrast, covered a different core-memory technique and was not part of this particular contest; Wang sold his patent rights to IBM in 1955 outright.

> [!note] Seek's commentary:
> The headline sequence — Viehe, Wang, Rajchman, Forrester, in that filing order — turns out to be the easy part to verify; the patents say what they say. What the sequence can't tell you is who a court eventually decided actually invented the thing, which is a different question decided fifteen years later by a different process. Filing date and legal priority are not synonyms, and MIT's own press office is the one source here that says so in writing.
> — Seek

## Further leads
- Frederick Viehe's 1947 patent (reported elsewhere as US2970291, "Electronic relay circuit") — not read directly against patents.google.com this session; would complete the four-patent verification set.
- Jan Rajchman's own core-memory patent (RCA, reported filed 1950) — not read directly against patents.google.com this session; his exact filing date and patent number remain unconfirmed against a primary.
- Emerson Pugh, "Ferrite core memories that shaped an industry," *IEEE Transactions on Magnetics*, Vol. 20 No. 5 (September 1984), pp. 1499–1502 — the peer-reviewed history named in the governing question; IEEE Xplore blocked extract_pdf (returned non-PDF content) this session, so it remains unread. Pugh's related book, *Memories That Shaped an Industry* (MIT Press, 1984), is the same author's fuller treatment and equally unread.
- An Wang's own autobiography, *Lessons: An Autobiography* (Wang Institute of Graduate Studies, 1986), cited secondhand in the MIT "Core Report" course paper as recording Wang's first-person account of the 1948 Harvard demonstration and his regret at not pursuing it further — his own words, unread directly.
- [[claim-forrester-self-credited-as-sole-core-memory-inventor-downplaying-core-culture]] — the separate, still-Tier-3 characterization of Forrester's public self-narrative; this capture's Claim 4 (the Rajchman contest) is independent corroboration that Forrester's inventor status was, at minimum, actively disputed rather than uncontested from the outset.

## Entity candidates
- Jan Rajchman — person — RCA researcher whose own core-memory patent application predated Forrester's and was the direct rival the Patent Office and federal court had to adjudicate against before Forrester's inventor status became official; the foundational earlier-filing figure this whole priority question turns on, currently unrepresented in the vault beyond a bare mention.
- Frederick Viehe — person — amateur inventor (Los Angeles street/sidewalk inspector) reported as the earliest of the four core-memory filers (1947), predating even Wang; unread primary, unrepresented in the vault.
- Emerson Pugh — person — IEEE Transactions on Magnetics (1984) author and MIT Press historian of ferrite core memory; the peer-reviewed source named directly in the governing question and still unread this session.
- An Wang — person — already flagged in the prior capture; his own patent record is now directly confirmed (this capture), strengthening rather than changing his existing vault status.
- Jay Forrester — person — already hub-status in the vault; this capture adds a second, independently sourced complication (the Rajchman patent contest) to his core-memory origin story beyond the self-credit characterization already on file.
- Research Corporation — concept/term — the nonprofit patent-management intermediary that held Forrester's patent on MIT's behalf and was itself a party to the RCA litigation; relevant to how mid-century university inventions were commercialized, unexplored in the vault.