Editing Terminal node controller (section)

{{Refimprove|date=September 2016}}

[[Image:Terminal Node Controller.jpg|thumb|AEA (Advanced Electronic Applications Inc.) PK-232MBX, circa 1991]]

A '''terminal node controller''' ('''TNC''') is a device used by [[amateur radio]] operators to participate in [[AX.25]] [[packet radio]] [[Computer network|network]]s.  It is similar in function to the [[Packet Assembler/Disassembler]]s used on [[X.25]] networks, with the addition of a modem to convert baseband digital signals to audio tones.<ref>{{cite book
|editor = R. Dean Straw
|title = The ARRL Handbook for Radio Communications 2006
|pages = 9.14–9.15
|isbn = 0-87259-948-5
|year = 2005
|publisher = [[American Radio Relay League]]
}}</ref>

The first TNC, the VADCG board, was originally developed by Doug Lockhart, VE7APU, of [[Vancouver]], [[British Columbia]].<ref>Larry Kenney. [http://www.choisser.com/packet/part01.html "Introduction to packet radio"].</ref>

Amateur Radio TNCs were first developed in 1978 in Canada by the Montreal Amateur Radio Club and the Vancouver Area Digital Communications group.  These never gained much popularity because only a bare [[printed circuit board]] was made available and builders had to gather up a large number of components.
{{specify |reason=By "these", do you mean all TNCs? All TNCs developed in Canada? The first TNC?}}

In 1983, the [[Tucson Amateur Packet Radio]] (TAPR) association produced complete kits for their TNC-1 design.  This was later available as the [[Heathkit]] HD-4040.  A few years later, the improved TNC-2 became available, and it was licensed to commercial manufacturers such as [[MFJ Enterprises|MFJ]].

In 1986, the improved "TNC+" was designed to run programs and protocols developed for the original TNC board.
TNC+ also included an assembler and a version of Forth ([[STOIC]]), which runs on the TNC+ itself, to support developing new programs and protocols.<ref>Douglas Lockhart. (1986). [https://www.tapr.org/pdf/CNC1986-FeaturesOfVadcgTNCplus-VE7APU.pdf "Features of the VADCG TNC+"]. Vancouver Amateur Digital Communications Group.</ref>

In 2018 Nino Carillo (KK4HEJ) developed and produced a TNC (the ''NinoTNC'')<ref>{{Cite web |title=TARPN -- NinoTNC info for Builders |url=https://tarpn.net/t/nino-tnc/nino-tnc.html |access-date=2024-09-01 |website=tarpn.net}}</ref> with (currently) 16 different data modes, from 300 baud AFSK to 19,200 C4FSK.It has a KISS interface to the compute device, and implements IL2P (Improved Layer 2 Protocol)<ref>{{Cite web |title=TARPN: Improved Layer-2 Protocol |url=https://tarpn.net/t/il2p/il2p.html |access-date=2024-09-01 |website=tarpn.net}}</ref> for Forward Error Correction (FEC) in some modes.