Standards ECP
You have found the way to ECP on Standards:
Computer Interface - Parallel interface information from Usbyte.com.
IEEE 1284/EPP/ECP Frequently Asked Questions - Answers and insight into some of the common questions and misunderstandings regarding the 1284 parallel port standard and its usage.
Interfacing the Extended Capabilities Parallel Port - Describes interfacing the ECP complete with register details and waveforms.
TN 0078 - Proposed ECP Interface to replace the memory board of the Mark IV.
Warp Nine Engineering - The Extended Capability Port, or ECP, protocol was proposed by Hewlett Packard and Microsoft as an advanced mode for communication with printer and scanner type peripherals. Help build the largest human-edited directory on the web.