ECP

Microsoft and Hewlett-Packard developed the ECP specification to extend the speed of the humble parallel port and to provide two-way throughput. Like the supercharged EPP spec, ECP is fast and bidirectional, but it works a little better than EPP in a multitasking environment because of its use of direct memory access (DMA) and buffering. Windows 95 supports ECP, but as of the end of 1995 a lot of exotic parallel port hardware (scanners, CD-ROM drives, and the like) didn't like the way the spec used DMA. Since both ECP and EPP are supported by the IEEE 1284 specification, many new parallel ports can run in either fashion.