Hayes Microcomputer Products — 2 prefixes (MA-L)

Hayes Microcomputer Products holds two MA-L (24-bit OUI) blocks in the IEEE registry, 00:00:DC and 00:00:CF, both registered under the organization name "HAYES MICROCOMPUTER PRODUCTS" — 00:00:DC to the U.S. parent (P.O. Box 105203, Atlanta, GA) and 00:00:CF to a Canadian subsidiary ("(Canada) Ltd.", CA). The company is a landmark of PC networking history: founded by Dennis Hayes and Dale Heatherington as D.C. Hayes Associates in 1978 and renamed Hayes Microcomputer Products in 1980, it defined the dial-up modem era with the Smartmodem and the Hayes AT command set — a control syntax so dominant it remains the de facto standard in modems and cellular modules to this day. The very low 00:00:xx OUI numbers place these assignments among the earliest IEEE allocations, consistent with a networking vendor active from the late 1970s. The two prefixes almost certainly identify networked Hayes gear from its later era — after the mid-1990s Access Beyond merger, Hayes shipped ISP-grade rack-mount modem banks and terminal servers, Ethernet-addressable products that would carry a MAC, unlike the early serial-only Smartmodems. The company merged into Hayes Communications, entered Chapter 11, and was liquidated in 1999; the Hayes brand was subsequently acquired by Zoom Telephonics. For MAC-classification purposes these are legacy prefixes: a match indicates vintage Hayes networking hardware, and no CVE, botnet, or abuse telemetry is associated with the vendor — expected for a maker whose active hardware era predates the IoT threat landscape.

IEEE assignment

2 prefixes → HAYES MICROCOMPUTER PRODUCTS [Confirmed] — IEEE MA-L (direct read: 00:00:DC + 00:00:CF)

Prefix 00

00:DC: HAYES MICROCOMPUTER PRODUCTS, P.O. BOX 105203, ATLANTA GA, US 30348 [Confirmed] — IEEE MA-L

Prefix 00

00:CF: HAYES MICROCOMPUTER PRODUCTS (Canada) Ltd., CA — registry address truncated to "(CANADA) LTD." + country code CA; no street/city/postal in source [Confirmed] — IEEE MA-L

Registry / block size

MA-L (24-bit OUI); 2 blocks. No MA-M (the IEEE MA-M registry) or MA-S (the IEEE MA-S registry) assignment found for this vendor [Confirmed] — IEEE registries (direct read of the IEEE MA-L registry, the IEEE MA-M registry, the IEEE MA-S registry). NOTE: IEEE's public OUI data publishes NO assignment/registration date (the IEEE MA-L registry columns are only Registry, Assignment, Organization Name, Organization Address); any "date registered" on third-party tools is a database artifact, not an IEEE fact.

HQ / country

Atlanta / Norcross, Georgia, US (US parent); Canadian subsidiary for 00:00:CF [Confirmed] — IEEE MA-L; en.wikipedia.org/wiki/Hayes_Microcomputer_Products

Company status

defunct — liquidated 1999; brand later acquired by Zoom Telephonics [Confirmed] — en.wikipedia.org/wiki/Hayes_Microcomputer_Products

Founded

as D.C. Hayes Associates 1978 by Dennis Hayes and Dale Heatherington; renamed Hayes Microcomputer Products 1980 [Confirmed] — en.wikipedia.org/wiki/Hayes_Microcomputer_Products; en.wikipedia.org/wiki/Dennis_Hayes_(businessman)

Device types

dial-up modems (S-100 modems, Smartmodem series, ESP/high-speed modems and modem cards); later ISP rack-mount modem banks and terminal servers after the Access Beyond merger [Likely — the networked later-era products are the plausible MAC-bearing category; early serial modems would not carry a MAC] — en.wikipedia.org/wiki/Hayes_Microcomputer_Products

Notable products

Smartmodem; Hayes AT command set (industry-defining, still used in modems/cellular modules) [Confirmed] — en.wikipedia.org/wiki/Hayes_Microcomputer_Products

Registration date

Unknown — IEEE publishes no OUI assignment/registration date; not fabricated [Confirmed absence] — IEEE the IEEE MA-L registry has no date column

Security / abuse

none found — no CVEs, botnets, or documented vulnerabilities tied to the vendor or its prefixes [Likely] — consistent with a pre-IoT-era legacy hardware maker (no telemetry hits)

Substance verdict

substantive company (not a bare single-OUI shell) — identifiable, well-documented vendor + product/device context + multiple OUI assignments [Confirmed]