Editing KA9Q (section)

'''KA9Q''', also called '''KA9Q NOS''' or simply '''NOS''', was a popular early implementation of [[Internet protocol suite|TCP/IP]] and associated protocols for amateur [[packet radio]] systems and smaller [[personal computer]]s connected via serial lines. It was named after the [[amateur radio]] [[call sign|callsign]] of [[Phil Karn]],<ref>{{foldoc|KA9Q}}</ref> who first wrote the software for a [[CP/M]] system and then ported it to [[DOS]] on the [[IBM PC]]. As the KA9Q package included source code, many radio amateurs modified it, so many different versions were available at the same time.

KA9Q was later maintained by Anthony Frost (callsign G8UDV) and Adam Goodfellow. It was ported to the [[Acorn Archimedes]] by Jonathan Naylor (G4KLX).  Until 1995 it was the standard access software provided by British dial-up [[internet service provider]] [[Demon Internet]].

Most modern operating systems provide a built-in implementation of [[Internet protocol suite|TCP/IP]] protocol; Linux especially includes all the necessary kernel functions and support utilities for TCP/IP over amateur radio systems, as well as basic [[AX.25]] and NET/ROM functionality. Therefore, NOS is regarded as obsolete by its original developer. It still may have its uses for embedded systems that are too small for Linux.<ref>{{Cite web |url=http://embedded.soe.ucsc.edu/pubs/tr96-29/html/tr96-29.html |title=JN: An Operating System for an Embedded Java Network Computer |access-date=2014-04-25 |archive-url=https://web.archive.org/web/20120824010637/http://embedded.soe.ucsc.edu/pubs/tr96-29/html/tr96-29.html |archive-date=2012-08-24 |url-status=dead }}</ref>

'''KA9Q''' is also a name for the IP-over-IP [[Tunneling protocol]].