Preface: Format is temporary and will eventually by replaced. Suggestions for final format are welcome. Suggestions for permanent jargon codes are also welcome.

Temporary Jargon codes
JJTN Telecommunications, North American
JJTU Telecommunication universal
JJIB IBM mainframe
JJAP APL jargon
JJCI Computer Industry
JJSC Semiconductor industry

JJTN Western Electric designed 300baud frequency shift keying modem used to connect 134.5bps and 300bps terminals to remote computers.
JJIB Imitation 2703 built by Memorex.
JJIB Communications controllers which connected many low speed terminals to an IBM mainframe via a byte multiplexor channel.
JJIB IBM built 134.5bps (15cps) terminal using Selectric typeball as print mechanism.
JJIB IBM built batch terminals with card reader/punch and line printer.
JJIB IBM built computer to connect many terminals at both low and high speeds to an IBM mainframe. Pre-release codename was 270RN. It replaced the IBM 2703.
JJSC Intel designed chip to replace UART and support bisync framing (aka USART).
JJSC AMD designed imitation of the 8251
acoustic coupler
JJTU Modem with an acoustic connection to the phone system. Relaxation of rules applying to devices connected to the telephone work has made them obsolete.
JJSC Advanced (sic) Micro Devices designer of the 9551 chip
JJIP Computer Automation Alpha LSI-2 used as node in IPSANET
JJCI A Programming Language
JJAP Popular APL interpreter for the IBM/360 370 etc
asynchronous modem
JJTU Modem which transmits data but not clock (see synchronous modem)
asynchronous port
JJTU Place to attach asynchronous device or modem to a computer
JJTU slang for asynchronous
JJTU device which make a dial telephone call under computer control
JJTU Scheme for sensing the operating speed of an attached dialup terminal
JJIP scheme such that an APL workspace started execution when loaded. QuadLX replaced it.
back pressure relief
JJIP Flow control mechanism in IPSANET
Bell Canada
JJTN Dominant telephone company in Canada
JJIP 80286 based computer used as node in IPSANET NET90 project
JJIB Synchronous communication protocol defined by IBM; used mainly for batch work.
JJIP see back pressure relief
byte multiplexor channel
JJIB part of an IBM mainframe which allowed multiple slow devices to connect to the computer.
JJTU (Consultative Committee on International Telegraphy and Telephony) International standards body for telecommunication now known as ITU-T
JJIB Channel Command Word, Basic unit in a program for a System/360 channel
JJTU European Conference of Postal and Telecommunications Administrations, a cartel
CNCP Telecommunications
JJTN Canadian common carrier spun off from railroad telegraph operations. Now part of MTS Allstream Inc
JJTU Synchronous modem manufacturer; responsible for CCITT V.29
JJAP Command which saved a workspace and forced a logoff. Also the name of the workspace saved by the command.
JJTU Data transmission unit in some protocol that contains the addresses of both sender and receiver
JJCI A major computer magazine published in USA. (now defunct)
JJTN TCTS Packet switching service which used X.25
JJTN TCTS Multiplexing service which offered fixed circuits across Canada
data link control
JJTU Protocol which connects two adjacent nodes in a packet switching system
JJTU Remote access to a computer established from a terminal to the computer
JJTU Remote access established from a central computer to some other device or computer.
Directran 611
JJTN Dataroute asynchronous limited distance modem. It passed data accurately but carrier loss signalling was inferior to that provided by a tin can on a string.
DLL (Down Line Load)
JJIP Protocol for reloading an Alpha from central computer.
JJTU Terminal to computer protocol such that every character received by the computer is returned to the terminal where it is displayed.
JJIB Emulator SubChannel, Part of a 3705's address space on the byte multiplexor channel.
event trapping
JJIP SHARP APL extension which allowed the APL programmer to retain control after certain errors and external events
foreign exchange
JJTN Telephone line which allows a user in one city to access an office or computer in another city without paying long distance charges.
framing protocol
JJTU Rule for delimiting transmission units in a data communications system.
JJTU A class of point to point communication protocols such that both ends may transmit simultaneously.
JJTU A class of point to point communication protocols such that only one end of allowed to transmit at any time.
HASP multileaving
JJIB Protocol which allowed a remote batch terminal (originally an IBM 360/20) connected to an IBM mainframe to simultaneously operate card reader and line printer.
high order line
JJIP Telecommunication link which connected two adjacent nodes in IPSANET.
JJCI International Business Machines (another expansion was used within IPSA)
JJIP the answering end of a virtual call
JJIP A customer who operated their own SHARP APL system using software licensed from IPSA.
initiated line
JJIP IPSANET High Order line that was ready to transmit data
JJSC Dominant semiconductor supplier
JJIP IPSANET protocol level which allowed the two ends of a network call to communicate (similar to Transport Layer in OSI model).
JJIP IPSANET protocol used to connect two adjacent nodes. Same as data link control
JJIP Alpha being reloaded in IPSANET Down Line Load protocol
low order line
JJIP Originally an Alpha physical port which connected one asynchronous terminal. Later extended to other device types including X25 virtual call terminations.
Macrodata BV
JJIP A company owned by Michael Harbinson which supplied some custom designed electronics to IPSA.
JJCI Supplier of peripherals to IBM customers. Their 660 disk drive was promoted with the slogan: Is it live or is it Memorex?
JJTU Manufacturer of high quality synchronous modems (later Racal Milgo)
JJTU device which converts digital data to and from an analogue form for transmission.
multi-drop line
JJTU A method of connecting several remote stations to a central controller via a single line. The order of transmission from the remotes to the controller is determined by interrogation polls from the controller. A fuller explanation can be found here.
JJTU Device which allows several logical channels to share the same physical channel.
JJIP An APL task with no attached terminal.
JJIP An extension of shared variables to remote SHARP APL systems.
JJIP The originating end of a virtual call.
JJIP An APL task used in IPSA dialin bisync
JJAP 8 residue X is remainder after division of X by 8
JJTU Algorithm used to move packets through a packet switching system.
Scientific Time Sharing Corporation
JJAP aka STSC An early US vendor of APL time-sharing.Some STSC material can be found here.
JJIB IBM designed communication protocol designed as Bisync replacement. Includes framing and data link control rules.
JJIP Variant of APL\360
JJAP see Scientific Time Sharing Corporation
synchronous modem
JJTU Modem which transmits both data and clock (normally runs at much high speed than asynchronous modem).
synchronous port
JJTU Computer port which connects a synchronous modem. (Traditionally much more expensive than an asynchronous port)
JJTN Trans Canada Telephone System, Consortium of Canadian telephone companies which used to offer joint services. Deregulation has put them in decline.
JJTN slang for telephone company
JJTN (formerly Canadian Overseas Telecommunications Corporation) An unregulated monopoly owned by the Government of Canada which was the sole provider of telecommunication services to countries other than the USA. Now bankrupt
JJTU 5-bit code teletype communications system for both dialup and fixed lines.
time division multiplexor
JJTU A device which allows the data streams from several slow data terminals of known data rate to be interleaved and transmitted via a high speed modem.
JJIP SHARP APL task with an attached terminal
JJSC Integrated circuit which eased the connection of asynchronous devices to a computer.
uninitiated line
JJIP A High order line which cannot currently transmit data (usually due to a modem or telephone line problem).
virtual call
JJTU Packet switching scheme which allows a pair of network ports to communicate (similar to spirit to an ordinary telephone call).
JJIP SHARP APL extension such that when an APL program entered immediate execution (from interruption or completion) a CONTINUE command was executed to save a workspace and disconnect.
JJSC Manufacturer of microcontrollers and accessories