Yokogawa Digital Computer Corporation — 3 prefixes (MA-L)

Yokogawa Digital Computer Corporation holds three MA-L blocks — 00:00:64, 00:60:41, and D0:0A:AB — all registered to the same entity at the Shinjuku MIDWEST Building, 4-30-3 Yoyogi, Shibuya-ku, Tokyo 151-0053, Japan. This is not a bare single-prefix shell: it is an identifiable, historically active company. It was the embedded-tools subsidiary of the Yokogawa Electric group, best known for embedded-development and debug hardware rather than general networking gear — in-circuit emulators (the "advice"/AZ series), the NETIMPRESS line of on-board flash microcontroller programmers, and the RAMScope high-speed RAM data-measurement tools. These are engineering-bench instruments for microcontroller development, the kind of equipment that carries Ethernet interfaces for host-PC connectivity and would draw MAC addresses from the company's own OUI allocations. The company's most important identity caveat is corporate: on 2017-04-01 Yokogawa Digital Computer Corporation merged into and became DTS INSIGHT CORPORATION, which still trades today as an embedded-tools vendor and partner listed by Toshiba, Infineon, STMicroelectronics, and Keil. Toshiba's partner directory explicitly labels DTS INSIGHT as "(formerly Yokogawa Digital Computer Corporation)," confirming the lineage. Two disambiguations matter for anyone researching this OUI. First, do not conflate this entity with "Yokogawa Digital Corporation," a separate subsidiary Yokogawa Electric established in 2022 for manufacturing-DX services — a different company. Second, the CISA/ICS-CERT advisories on file for "Yokogawa" (e.g., FAST/TOOLS, recorder products) belong to the parent Yokogawa Electric Corporation's industrial process-control lines, not to this OUI holder; no security advisory names this entity or these three prefixes specifically. No specific product-to-prefix mapping and no IEEE registration date are published — IEEE's OUI registry carries no assignment-date field, so none is asserted here.

IEEE assignment

3 prefixes → Yokogawa Digital Computer Corporation, Tokyo, JP [Confirmed] — IEEE MA-L (local registry snapshot the IEEE MA-L registry / the Wireshark manufacturer database; corroborated by two independent angles)

Registry / block size

MA-L (24-bit OUI); holds 3 IEEE prefixes [Confirmed] — IEEE MA-L. NOTE: IEEE's public OUI data publishes NO assignment/registration date (columns are only Registry, Assignment, Organization Name, Organization Address); any "date registered" on third-party tools is a database artifact, not an IEEE fact.

Verified prefixes (all MA-L, Yokogawa Digital Computer Corporation)

00:00:64, 00:60:41, D0:0A:AB [Confirmed] — IEEE MA-L registry snapshot

HQ / country

Shinjuku MIDWEST Bldg., 4-30-3 Yoyogi, Shibuya-ku, Tokyo 151-0053, JP (registry address, identical across all three blocks) [Confirmed] — IEEE MA-L

Company status

merged — became DTS INSIGHT CORPORATION on 2017-04-01; successor entity is active [Confirmed] — dts-insight.co.jp corporate history; Toshiba partner directory ("formerly Yokogawa Digital Computer Corporation")

Industry

embedded development / debug tools (in-circuit emulation, flash programming, RAM measurement) [Confirmed] — Toshiba partner directory; DTS INSIGHT product history

Device types

embedded-development / debug hardware — in-circuit emulators ("advice"/AZ series), NETIMPRESS on-board flash programmers, RAMScope RAM data-measurement tools; not general networking equipment [Likely] — Toshiba partner directory, product listings (per-prefix-to-model mapping not documented)

Per-prefix → product mapping

which of the three prefixes belongs to which product model is not published [Unknown] — no vendor documentation found itemizing this

Security context

no CVEs, ICS-CERT/CISA advisories, or bulletins name this entity or these three OUIs; CISA "Yokogawa" advisories (e.g., ICSA-26-041-01 FAST/TOOLS, ICSA-25-107-04 Recorder) belong to the separate parent Yokogawa Electric Corporation and are NOT attributed here

[Confirmed] — cisa.gov ICS advisories (checked; different legal entity)

Disambiguation

distinct from "Yokogawa Digital Corporation" (a 2022 Yokogawa Electric manufacturing-DX subsidiary) — do not conflate [Confirmed] — yokogawa.com press release (2022)

Registration date

not applicable — IEEE publishes no OUI assignment date; none recorded (not fabricated) [Confirmed] — IEEE MA-L data schema

Related vendors

Yokogawa Electric Corporation (parent group); DTS INSIGHT CORPORATION (successor after 2017 merger)