Description: Parallel Interface Card: Product Description (11/96)
Header: Parallel Interface Card: Product Description (11/96)

 Article Created: 24 October 85
 Article Reviewed/Updated: 19 November 1996

 TOPIC -----------------------------------------------------------

 This article describes the Apple II Parallel Interface card and includes
 other related information.

 DISCUSSION ------------------------------------------------------

 DB-25 Connector Pinout
 ----------------------
 DB-25
 Connector       Signal Name

 1..............Data In, Bit 0
 2..............Signal Ground
 3..............Data In, Bit 2
 4..............Signal Ground
 5..............Data Out, Bit 0
 6..............Data Out, Bit 1
 7..............Blocked
 8..............Data Out, Bit 2
 11..............Data Out, Bit 5
 12..............Data Out, Bit 6
 13..............Data Out, Bit 7
 14..............Data In, Bit 4
 15..............Strobe Out
 16..............Acknowledge In
 17..............Data In, Bit 1
 18..............Data In, Bit 7
 19..............Data In, Bit 5
 20..............Signal Ground
 21..............Data In, Bit 6
 22..............Data Out, Bit 3
 23..............Data Out, Bit 4
 24..............Signal Ground
 25..............Data In, Bit 3


 Switch Settings
 ===============


 Strobe Length
 -------------
 1 microsecond     -> SW1-1:Off, SW1-2:Off, SW1-3:Off
 3 microseconds    -> SW1-1:On,  SW1-2:Off, SW1-3:Off
 5 microseconds    -> SW1-1:Off, SW1-2:On,  SW1-3:Off
 7 microseconds    -> SW1-1:On,  SW1-2:On,  SW1-3:Off
 9 microseconds    -> SW1-1:Off, SW1-2:Off, SW1-3:On
 11 microseconds   -> SW1-1:On,  SW1-2:Off, SW1-3:On
 13 microseconds   -> SW1-1:Off, SW1-2:On,  SW1-3:On
 15 microseconds   -> SW1-1:On,  SW1-2:On,  SW1-3:On


 Strobe Polarity
 ---------------
 Positive   -> SW1-4:Off
 Negative   -> SW1-4:On
 Ack Polarity
 ------------
 Positive   -> SW1-5:Off
 Negative   -> SW1-5:On


 Firmware Select
 ---------------
 Parallel (LF)        -> SW1-6:Off
 Centronics (No LF)   -> SW1-6:On


 Interrupts
 ----------
 Disable   -> SW1-7:Off
 Enable    -> SW1-7:On

 Interrupts should be enabled for the Apple III and disabled for the Apple II.


 Switch Setting Explanations
 ---------------------------
 Different peripherals (non-Apple printers, etc.) may use I/O signals that
 have different duration and polarity. The STROBE LENGTH, STROBE POLARITY, and
 ACK POLARITY switch settings on the Parallel Interface Card (2PIC) give you
 the flexibility to communicate with these other devices. For the I/O signal
 characteristics of the device you are connecting with, read its manual.


 Controlling Bit 8
 -----------------
 The following program enables you to control bit 8, used by some printers to
 select expanded or normal print mode or to enable alternate or graphics
 character sets. DOS 3.2 or DOS 3.3 is required to use this routine, which
 also works in the Apple III in Emulation mode.

 Determine which slot your interface card is in and the corresponding slot
 code from the table.  Replace "<slot>" with the slot number and "<code>" with
 the code when typing in the program.

 slot      1    2    3    4    5    6    7
 code     C1   C2   C3   C4   C5   C6   C7

 Enter the monitor with Call -155 and type:

 3B0:A9 <slot>
 :20 95 FE
 :A9 80
 :20 ED FD
 :A9 C5
 :85 36
 :A9 03
 :85 37
 :4C EA 03
 :29 7F
 :0D CD 03
 :4C 02 <code>
 :80

 To check your typing, type: 3B0L
 Compare your listing to the one below configured for slot 1.

 03B0-   A9 01       LDA   #$01
 03B2-   20 95 FE    JSR   $FE95
 03B5-   A9 80       LDA   #$80
 03B7-   20 ED FD    JSR   $FDED
 03BA-   A9 C5       LDA   #$C5
 03BC-   85 36       STA   $36
 03BE-   A9 03       LDA   #$03
 03C0-   85 37       STA   $37
 03C2-   4C EA 03    JMP   $03EA
 03C5-   29 7F       AND   #$7F
 03C7-   0D CD 03    ORA   $03CD
 03CA-   4C 02 C1    JMP   $C102
 03CD-   80          ???

 Enter 3D0G to return to Basic.

 Save the driver to disk by typing: BSAVE CEN 730, A$3B0, L$1E

 Load the driver and initialize the interface before using the printer. From
 command mode, type:

 BLOAD CEN 730
 Call 944

 Or from a program: 100 Print D$;"BLOAD CEN 730" : Call 944, assuming that D$
 is a CTRL-D.

 To switch back to the video monitor for output type: PR#0
 or in a program enter: 200 Print D$;"PR#0"

 To reconnect the printer, all that is required is: Call 954, or from a
 program: 300 Call 954

 To set normal print mode, type POKE 973,0; type POKE 973,128 to set the
 expanded print mode POKE.

 Cable Pinouts
 -------------
 Here is a sample pinout for an Apple II parallel card to a parallel printer.

 20-Pin         Amphenol
 DIL Connector  Connector
 (Female)       (Male)
 1  ----------  14
 2  ----------  10
 8  ----------  1
 10  ----------  2
 11  ----------  3
 12  ----------  4
 13  ----------  5
 14  ----------  6
 15  ----------  7
 16  ----------  8
 17  ----------  9
 20  ----------  16


 Article Change History:
 19 Nov 1996 - Reviewed for technical accuracy, revised formatting.
 Copyright 1988-96, Apple Computer, Inc.
 Keywords:  HTS,CNFG