Updating bios on eee pc
A further modification, "Bi-Directional", used the status pins to indicate the direction of data flow on the 8-bit main data bus; by indicating there was data to send to the host on one of the pins, all eight data pins became available for use.
This proved adaptable, and led to the "Enhanced Parallel Port" standard, which worked like Bi-Directional mode but greatly increased the signalling speeds to 2 MByte/s, and later the "Extended Capability Port" version increased this to 2.5 MByte/s.
IEEE-1284 requires that bi-directional device communication is always initiated in Nibble Mode.
If the host receives no reply in this mode, it will assume that the device is a legacy printer, and enter Compatibility Mode.
This led to an early expansion of the system introduced by HP, the "Bitronics" implementation released in 1992.
This used the status pins of the original port to form a 4-bit parallel port for sending arbitrary data back to the host.
As printers grew in sophistication, and the cost of memory dropped, printers began adding increasing amounts of buffer memory, initially a line or two, but then whole pages and then documents.
Instructions on how you can do this using one such software named Acronis True Image can be found here.In the printer venue, this allows for faster printing and back-channel status and management.Since the new standard allowed the peripheral to send large amounts of data back to the host, devices that had previously used SCSI interfaces could be produced at a much lower cost.Separate pins in the port allow status information to be sent back to the computer.This was a serious limitation as printers became "smarter" and a richer set of status codes were desired.