IEEE 1284
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IEEE1284PrinterCable_Nov-11-2004.jpg
IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices. It is most frequently used for connecting computers to printers but it has also been used to connect storage devices, for file transfer and remote access between computers, and to communicate with modems.
IEEE 1284 can use any of the following standard connectors:
- DB-25
- Centronics 36 pin
- Mini-Centronics 36 pin
The standard was created by the IEEE in 1998 after they were approached by the Network Printing Alliance (NPA), who were a group of printer manufacturers who required a higher speed, standardised parallel port specification. The standard is compatible with older parallel port modes, as well as newer modes like EPP and ECP mode.
The standard uses 8 wires to transmit data, allowing one byte (8 bits) to be transmitted at a time. Historically, parallel standards such as IEEE 1284 have been faster than their serial counterparts because they could transmit more data in one cycle. However, serial hardware and cables cost less to build and have smaller connectors. These advantages have driven new advances in serial technology such as USB, FireWire, and Serial ATA, which are quickly making parallel data transmission obsolete. All new PCs have USB ports, and some don't include an IEEE 1284 port any more due to their cost and bulkiness. Almost all new printers also have a USB connector. USB will clearly be used to connect PCs and printers in the future, however many older printers are still in service with IEEE 1284.
External links
- Warp Nine Engineering's introduction to the IEEE 1284-1994 standard (http://www.fapo.com/1284int.htm)
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