Specifications

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PJL - Printer Job Language - developed by the Hewlett Packard Company. It is printer
programming language which uses @PJL line commands to send a print job to a PJL-
compatible printer.
Port - The electronic hardware or software components allowing the CPU to
communicate with peripherals. The serial, parallel, AppleTalk ports are all examples
of I/O ports on controllers, PCs and Macs.
PostScript - The trade name of the Adobe PDL. First used by Apple.
PPD - PostScript Printer Description – a text file containing the characteristics of a
particular printer. Used by a PostScript printer driver to correctly send a file for
printing on a particular printer. All PostScript-capable printers must have a PPD file
to operate properly.
Print Manger - The computer’s operating system program that spools and otherwise
manages print jobs sent from the computer to various printers.
Print Queue - A list of files that a print spooler prints in the background while the
computer performs other tasks in the foreground.
Print server - A device and/or program that manages documents sent to a shared printer.
PROM - Programmable ROM – a ROM which may be programmed.
Protocol - Governing rules for communicating between two devices. Computers wishing
to communicate over a LAN must do so using the same protocol.
Queuing - The process of saving documents to be printed in the spooler, on a first-in-
first-out basis.
QuickDraw - Apple printer driver/management software that ships with their operating
system. QuickDraw is NOT compatible with the Adobe PostScript printer driver.
RAM - Random Access Memory - the computers non-permanent primary working
memory, in which program instructions and data are stored.
Rasterize - See RIP.
Registration - the alignment of color and graphics.
Removable Media - The storage component of a disk drive that may be removed and
replaced. Typically these are of 100 Mbyte or larger capacities and, except for the
removable feature, would be considered to be a hard drive. See also ZIP Drive and
SyQuest.
Repeater - A device used to extend cabling distances by regenerating signals.
Resident Fonts - Type fonts stored permanently in the controller or printer.
Ring topology - A closed-loop topology in which data passes in one direction from
station to station on the LAN. Each workstation on the ring acts as a repeater, passing
data to the next workstation on the ring.
RIP - Raster Image Processor/Processing – the process of converting the print control
codes sent from the computer printer driver into an image constricted of lines or dots,
to be printed on a screen or paper.