pin 1 /Strobe pin 2 Data 0 pin 3 Data 1 pin 4 Data 2 pin 5 Data 3 pin 6 Data 4 pin 7 Data 5 pin 8 Data 6 pin 9 Data 7 pin 10 /ACK pin 11 BUSY pin 12 PE (Paper End) pin 13 SEL pin 14 /Autofd (Auto Feed) pin 15 /Error pin 16 /INIT pin 17 /SELIN pin 18 /GND (for strobe) pin 19 /GND (for Data 0/1) pin 20 /GND (for Data 2/3) pin 21 /GND (for Data 4/5) pin 22 /GND (for Data 6/7) pin 23 /GND (for BUSY and Error) pin 24 /GND (for PE, SEL, ACK) pin 25 /GND (for AF, SELIN, INIT)
Here are some links with more information:
man 4 lp
The rub with usb to parallel gizmos, is that it may be problematic to get the chip inside to give raw access to individual pins. The usual protocol for sending data to a printer is to place 8 bits of data on the data pins, then do a handshake with BUSY, STROBE, and ACK which allows the printer to latch the data. Whether it is possible to just assert data on a pin (or to read data presented on a pin when in bidirectional mode) may be problematic.
Every USB printer device is expected to respond to this set of standard USB printer commands.
ID 067b:2305 Prolific Technology, Inc. PL2305 Parallel Port(So I could have saved myself the small bother of prying it apart). In fact, when I plug in my second unit (black with centronics connector), I get exactly the same information, so I do save myself the bother of prying it apart.
Adventures in Computing / tom@mmto.org