Brief specifications for comparing the ECP parallel port (on late model Toshiba computers) and EPP parallel port hardware.

EPP - Enhanced Parallel Port 

1-3 MB/sec 
Asynchronous, interlocked, bi-directional communication - Half Duplex Operation 
Targeted at register oriented type devices: 
Network Adapters 
Tape backup 
CD-ROM 
Master/slave architecture 
Peripheral is polled for data 
Supports peripheral interrupt 
Supports two cycle types: 
Address/command 
Data 
Symmetric Read/Write cycles 
Hardware assisted handshaking/data transfer 
Limited by I/O cycle capabilities of the implementation
 

ECP - Extended Capability Port

5 MB/Sec 
Asynchronous, interlocked, bi-directional communication - Half Duplex Operation 
Targeted at block oriented type devices: 
Printers 
Scanners 
May have hardware support for RLE compression or decompression (optional) 
Supports 2 cycle types: 
Channel Address 
Data 
Peer to 'Peerish' 
Peripheral may request the reverse channel, but the host controls the data transfer 
Hardware assisted handshaking/data transfer 
Implementations include DMA as well as programmed I/O PC interface 
Data transfer rate limited by the DMA or I/O cycle capabilities of the implementation