Parallel Interface Card: Jumper Block Modification (11/96)



This article details how to modify the Parallel Printer Interface card to work with different parallel printers. Refer to the card manual for more information on these modification.



There are two features that can be modified on the Parallel Card, the wiring of the jumper block and the PROM at location "Prom P1"


Jumper Block
------------
The wiring of the jumper block controls the correct polarity of the strobe and acknowledge signals. Here is an example of the wiring for a "Centronics-type" printer.

   Block
4 -------16            negative strobe, negative acknowledge
6--------14 AND 15
7--------10
11--------12 AND 13

Notch on jumper block denotes pin 1, the count CCW


PROM 1
------
The location marked "Prom P1" on the card will work with two different PROMs which produce different results when installed. To change the results, just remove one PROM and install the other.

NAME        APPLE PART #     RESULTS

P1 PROM     341-0005         Automatically initializes printer
                            to 80 column.
                            No carriage return generated after
                            every linefeed.

P9 PROM     341-0019         No auto initialization to 80 column
                            mode.
                            Generates a carriage return after
                            every linefeed.


Article Change History:
19 Nov 1996 - Reviewed for technical accuracy, revised formatting.
Published Date: Feb 18, 2012