You can have some of the features of ECP like FIFO buffers and hardware generation of handshaking butwith the existing SPPhandshake instead of the ECPHandshake.

The Extended Capabilities Mode was designed by Hewlett Packard and Microsoft.

This protocol uses additional hardware to generate.

Encoding (RLE) to achieve data compression ratios up to 64:1.

This comes.

The Extended Capabilities Port supports a method of channel addressing.

This is not intended to be used to daisy chain devices up but rather to.

EPP. This means that there is also a different handshake method when using.

SPP and thus are labeled Strobe, Auto Linefeed, Init, Busy etc.

The HostAck and PeriphAck lines indicate whether the signals on the data.

HostAck will be low or if the deviceperipheral is sending a command the.

A command cycle can be one of two things, either a RLE count or an address.

This is determined by the bit 7 (MSB) of the data lines, ie Pin 9.

If bit.

If we look back at the SPP Handshake you will realize it only has 5 steps.

As briefly discussed earlier, the ECP Protocol includes a Simple Compression.

For example, if a string of 25 As were to be sent, then a run count byte.

The Run Length Byte has to be distinguished from other bytes in the Data.

Path. It is sent as a Command to the ECPs Address FIFO Port.

Bytes sent.

The table below shows the registers of the Extended Capabilities Port.

The first 3 registers are exactly the same than with the Standard Parallel.

Port registers. Note should be taken, however, of the Enable Bi-Directional.

Port bit (bit 5 of the Control Port.) This bit reflects the direction that.

The most important register with a Extended Capabilities Parallel Port.

The three MSB of the Extended Control Register selects the mode of operation.

There are 7 possible modes of operation, but not all ports will support.

Spp Mode Epp Std Mde Bios