Acorn Computers Limited — 00:00:A4 (MA-L)

Acorn Computers Limited holds a single IEEE MA-L block, 00:00:A4, registered under the legacy address "Fulbourn Road, Cherry Hinton, England." A one-prefix footprint would normally flag a vendor as a bare shell, but Acorn is a historically substantial company: founded in Cambridge in 1978 by Hermann Hauser, Chris Curry, and Andy Hopper, it built the BBC Micro that dominated British classroom computing through the 1980s and won a Queen's Award for Technology in 1984, then shipped the Acorn Archimedes in 1987 as the first RISC-based home computer. Acorn's in-house RISC processor design was spun out in 1990 as Advanced RISC Machines — the lineage that became Arm Holdings. On the networking side, Acorn's machines originally ran the proprietary, non-Ethernet Econet bus before moving to Acorn Universal Networking (AUN), a TCP/IP-over-Ethernet successor whose interface cards are the plausible device class behind this OUI, though no source ties 00:00:A4 to a specific card model by name. The company wound down as an active hardware vendor around 1998–2000.

IEEE assignment

00:00:A4 → "ACORN COMPUTERS LIMITED," registered address "Fulbourn Road, Cherry Hinton, GB England" (no postal code present in the cached record) [Confirmed] — the IEEE MA-L registry

Registry / block size

MA-L (24-bit OUI); exactly one prefix is registered to this company [Confirmed] — the IEEE MA-L registry, corroborated by the Wireshark manufacturer database alias "AcornCompute" / "Acorn Computers Limited" [Confirmed] — the Wireshark manufacturer database

Date registered

Unknown / not applicable — IEEE's public OUI registry (the IEEE MA-L registry) publishes no assignment or registration date for any MA-L record; this is not attributable to IEEE [Confirmed] — the IEEE MA-L registry (schema; no date column)

Company status

defunct as an active hardware vendor since ~1998–2000; the OS/software unit was renamed Element 14, and RISC OS survives today only via the unrelated open-source RISC OS Open community [Likely] — https://en.wikipedia.org/wiki/Acorn_Computers, https://en.wikipedia.org/wiki/RISC_OS

Company history

founded 1978 in Cambridge, England by Hermann Hauser, Chris Curry, and Andy Hopper; made the BBC Micro (Queen's Award for Technology, 1984) and the Acorn Archimedes (1987, first RISC-based home computer); its ARM processor design was spun off in 1990 as Advanced RISC Machines, the lineage that became Arm Holdings

[Confirmed] — https://en.wikipedia.org/wiki/Acorn_Computers

Device types

proprietary Econet LAN (pre-Ethernet, CSMA-CD over a 5-wire bus, not MAC-addressed) succeeded by Acorn Universal Networking (AUN), TCP/IP over standard Ethernet; AUN-era Ethernet interface cards are the plausible device class for this OUI [Likely — inferential, no source names 00:00:A4 explicitly] — https://en.wikipedia.org/wiki/Econet, https://hackaday.com/2020/04/16/econet-britains-early-educational-network/

Security context

no CVEs or modern advisories tied to this OUI found; any device still emitting it on a live network today would be vintage/retro-computing hardware, not currently-manufactured product [Likely] — https://en.wikipedia.org/wiki/RISC_OS, https://en.wikipedia.org/wiki/Acorn_Computers

Related but distinct registry hits (NOT this vendor, must not be conflated)

the IEEE MA-M registry "Beijing Acorn Networks Corporation" (different company, MA-M block 90-C6-82); the IEEE MA-L registry "Synectics Systems Limited" (Acorn appears only as part of the street address "3 Acorn Business Park") [Confirmed] — the IEEE MA-M registry, the IEEE MA-L registry

Company substance assessment

single-OUI registration, but backed by an independently documented, historically significant company (BBC Micro, Acorn Archimedes, origin of the ARM architecture) — satisfies the bar for verifiable substance beyond a bare IEEE registration [Confirmed] — https://en.wikipedia.org/wiki/Acorn_Computers

Third-party date caveat

no IEEE registration date exists to report; any "date registered" shown by third-party MAC-lookup aggregators (maclookup.app, mac.lc, hwaddress.com, etc.) is a database/scrape artifact, not an IEEE fact, and is not recorded here [Confirmed] — the IEEE MA-L registry (schema)