J

JABBER

Network error caused by an interface card placing corrupted data on the network. OR, an error condition due to an Ethernet node transmitting longer packets than allowed, or continuously sending garbage.

JANET

See Joint Academic Network.

JERUSALEM B

The most common PC virus, with dozens of variants. Behavior common to many variants is display of a black box in the upper left part of the screen, system slowdown, and deletion of all programs executed on a trigger date (Friday the 13th, Tuesday the 13th, October 12th, January 25th, or any Friday after the 15th of the month).

JITTER

The slight movement of a transmission signal in time or phase that can introduce slight errors and loss of sync. in high speed sync. communications.

JOE

(Joe's Own Editor) Like emacs and ted, but can be customized through an initialization file. Variations include Jipico, Jstar, and Jmacs.

JOINT ACADEMIC NETWORK

(JANET) A university network in the U.K.

JOINT PHOTOGRAPHIC EXPERT GROUP

(JPEG) High-quality, single-picture spatial compression. Uses DCT algorithm (Discrete Cosine Transfer). Has been adapted to video but provides no frame compression. See also Delta Frame.

JOOTT

Just one of those things

JOSHI VIRUS

On January 5th, locks up the system and displays the message "type Happy Birthday Joshi." If the user types "Happy Birthday Joshi," the system again becomes usable.

JPEG

See Joint Photographic Expert Group.

JUGHEAD

A search engine for locating files stored on remote gopher systems.

JUMP INSTRUCTION

An instruction that causes the processor to deviate from executing instructions in order, by jumping to another place in the program.

JUNET

Japan UNIX Network.