Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)


bidirectional parallel port

See IEEE 1284.

IEEE 1284

An IEEE standard for an enhanced parallel interface (parallel port) for personal computers, superseding the Centronics interface. Introduced in 1994, IEEE 1284 can send addresses, allowing individual components in a multifunction device (printer, scanner, fax, etc.) to be addressed independently. Unlike the Centronics interface, the specifications of the cable are also defined in IEEE 1284, providing a cable length up to 32 feet. A legacy interface today, IEEE 1284 has been superseded by USB and network connections. See Centronics interface, DOT4 and USB.

Five Modes of Operation
The mode chosen by the software driver is based on the connected device. 1-Compatibility mode supports the Centronics interface at 150 KB/sec. 2-Nibble mode supports Bi-tronics; HP's parallel port variation. 3-Byte mode supports IBM PS/2 personal computers. 4-Enhanced Parallel Port (EPP) provides bidirectional speeds up to 1.5 MB/sec. 5-Enhanced Capability Port (ECP) is similar to EPP but can transfer 2.5 MB/sec using direct memory access (see DMA).

IEEE 1284 Printer Cable
Using the same Micro-Ribbon connectors as the Centronics interface, IEEE 1284 specifies higher-quality cables up to 32 feet long.

Personal Use Only

Before/After Your Search Term
bi-wiringbidirectional printer
bias voltagebifurcate
biasedBig Blue
BiCMOSBig Data
BICSIBig Data analytics
bid shieldingBig Data framework
bid sniperBig Drive
bidirectionalbig endian
bidirectional frameBig Five

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
ProgrammingHealthcare IT
System design