Filter
Top Products
Appendix A: Glossary
A-12
OS/2. IBM's PC operating system. Primarily significant because it is used as the file server op-
erating system on LAN Manager and LAN Server networks.
OS/400. The operating system used on IBM AS/400, iSeries and system 3X minicomputers.
OSF/1. DEC's version of UNIX that was originally called ULTRIX and is now called Digital
UNIX. OSF/1 uses the standard Berkeley lpr/lpd procedures for printing to remote host com-
puters and print servers.
OSI Reference Model. A seven-layer model developed by the International Standards Or-
ganization which is used as a reference for developing protocols. Since each layer performs a dif-
ferent function, development and debugging are simplified, and there is greater flexibility (for
example, this approach allows TCP/IP to run over both Ethernet and Token Ring).
P1284. An IEEE standard that defines a high-speed bi-directional parallel printer port. P1284
ports are also compatible with the Centronics standard. There are three types of physical con-
nectors associated with the 1284 standard: 1284A (25-pin DB25), 1284B (36-pin standard
Centronics), and 1284C (miniature Centronics).
Packet. A group of data and control information that is sent over a network. Often used inter-
changeably with frame, although frame is normally used with lower-layer protocols like Ethernet,
while packet is associated with higher layer protocols like IP and IPX.
Parallel Port. On a printer, a port that transfers data 8 bits at a time for maximum performance.
The parallel port usually has a 36-pin Centronics connector.
PATHWORKS. The Digital Equipment Corporation network operating system for PCs and
Macintosh computers.
PCL. Printer Control Language. A command language based on escape sequences that was
developed by Hewlett-Packard for its LaserJet printers.
PCONSOLE. A NetWare utility program for configuring and managing printers.
PDL. Page Description Language. A control language usually consisting of commands embed-
ded within a document that control the way the document will look when printed. Such com-
mands would set the type of fonts, page margins, colors, graphics, etc. within the document.
PDF. Printer Definition File. The Graphical Device Interface (GDI) default standard for
PC5250 printing, and it is the easiest of the three methods to use. Its disadvantages are that it
cannot print AS/400 office documents with embedded images and it cannot print AFP docu-
ments.