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Re: Null modem pinout



Had those pinouts somewhere, hold on...

This is from Apple Oasis. (A plug for Teodor, the author)

This should work for you. Teodor also includes a program which works as an
Apple disk server for IIE machines. Couldn't get it to work on my //c though.
Different joystick ports.

The null modem connection is a short cable and two connectors. The standard
serial connectors are DB-25 and DB-9. Following are their pin descriptions:

DB-9 Connector

    Pin   Signal                   Pin  Signal
-------------------------------------------------------------------
     1    CD   Carrier Detect       6   DSR  Data Set Ready
     2    RXD  Receive Data         7   RTS  Request to Send
     3    TXD  Transmit Data        8   CTS  Clear to Send
     4    DTR  Data Term. Ready     9   RI   Ring Indicator
     5    GND  Signal GND


DB-25 Connector

    Pin   Signal                   Pin  Signal
-------------------------------------------------------------------
     1    GND  Ground / Shield     14        {2nd TXD}
     2    TXD  Transmit Data       15        Transmit Clock
     3    RXD  Received Data       16        {2nd Rec. Clock}

     4    RTS  Request to Send     17        {Receive Clock}
     5    CTS  Clear to Send       18        {Unassigned}
     6    DSR  Data Set Ready      19        {2nd RTS}
     7    GND  Ground              20   DTR  Data Term Ready
     8    DCD  Carrier Detect      21        {Sig. Quality}
     9         {Reserved}          22   RI   Ring Indicator
    10         {Reserved}          23        {Data Rate Sel.}
    11         {Unassigned}        24        {Transmit Clock}
    12         {2nd CD}            25        {Unassigned}
    13         {2nd CTS}


Here is the Null Modem connection:

PC  (DB-9)                   Apple*(DB-25)

 RxD (2) ---------------------- TxD (2)
 TxD (3) ---------------------- RxD (3)
 GND (5) ---------------------- GND (7)

 RTS (7) --\                /-- RTS (4)
 CTS (8) --/                \-- CTS (5)

 CD  (1) --\                /-- DSR (6)
 DSR (6) --+                +-- DTR (20)
 DTR (4) --/                \-- CD  (8)


* For Super Serial Card (SSC) put the TERMINAL/MODEM jumper pointing up at
'MODEM'.