O2 Parallel Port:
Why does the parallel port look different than the Indy?
The O2 parallel port supports the new IEEE standard 1284C for parallel ports, including bidirectional I/O.
What are the pinouts on the parallel port?
O2 uses the standard IEEE 1284-C cable. The current Centronics 25-pin connector on host side is called IEEE 1284-A and 36-pin connector on printer side is called IEEE 1284-B. The O2 uses a 36-pin mini-connector called IEEE 1284-C which has different pin assignments than type A and type B. The type-C cable has been available for a while and should be available from most of the computer supply stores.
The IEEE 1284-C specification is described in IEEE Std 1284-1994 document "IEEE Standard Signaling Method for a Bidirectional Parallel Peripheral Interface for Personal Computers" page62-63. Customers requiring more details will need to order a copy of IEEE std 1284-1994 document or they can access FarPoint for some information.
Here is an IEEE 1284-C pin assigment in Compatible (Centronics) mode:
|1284C Pin||Signal Name||Signal Description||Centronics Pin|
|18||Peripheral logic HIGH|
|19||GND||signal ground (BUSY)|
|20||GND||signal ground (SELECT)|
|21||GND||signal ground (nACK)|
|22||GND||signal ground (nFAULT)|
|23||GND||signal ground (pERROR)|
|24||GND||signal ground (DATA 1)|
|25||GND||signal ground (DATA 2)|
|26||GND||signal ground (DATA 3)|
|27||GND||signal ground (DATA 4)|
|28||GND||signal ground (DATA 5)|
|29||GND||signal ground (DATA 6)|
|30||GND||signal ground (DATA 7)|
|31||GND||signal ground (DATA 8)|
|32||GND||signal ground (nINIT)|
|33||GND||signal ground (nSTROBE)|
|34||GND||signal ground (nSELECTIN)|
|35||GND||signal ground (nAUTOFEED)|
|36||Peripheral logic HIGH|