From: nevs@cs.tu-berlin.de (Sven Goldt)
Subject: rs232
Organization: Techn. University of Berlin, Germany
Date: Tue, 8 Sep 1992 08:49:54 GMT


This is a plan for building your own rs232-interface.
No guarantee.

                        O   O       O O  O           RS232 - PINS
                        |   | /""\  | |  |
                     O  | O | O O | O O  O  O
                     |  | | |  /  |     /   | 
                     |  | | | /   |    /     \O
                     |  O | O | O | O | O O O
                     |   /   /  | | | | | \ \
                     |   |  /   O | O | \  O |
                     |   |  |     |   |  \   |
                     |   |  | |""""    \  O  O
                     |   |  | |         |
                     |   |  | | O"""""""O"""""\
                     |   |  | |                \
                    /    |  \ """""""""""""""\  \
                   /     |   """""""""""\     \  \
                || ||"|| || || || || || || || || ||
                || || || || || || || || || || || ||  USERPORT - PLUG


Hardware:
=========
1 Chip MAX 232
4 El.Condensators 22 uF / 16 Volt
1 Userport - Plug with Userport - box
1 Platine


Look with Hardware on Platine:
==============================

                RS232-PINS    

                GND TXD CTS  RTS RXD
                7    2   5    4   3
                O    O   O    O   O

                ===================
 Bridge to        |o o o  o  o o o o|
 Pin 2 (+5V)    |    MAX 232      |
=========o        |o o o  o  o o o o|
of the U-Port   ===================
(Pin 2 to Pin 16 of MAX232)
                 +       +
                 //       //      //     Condensators
            \\                        +
            +                    


MAX232 - Connections:
=====================

                       + /\  + /\  + /\  + /\
                         = |   = |   = |   = |  CONDENSATORS
                         | |   | |   | |   | |
                    16 =======================
+5V      2   ----------|                     |
                       |     MAX 232         |
                    11 |                     | 14
PA2      M   ----------|                     |--------  TXD
                    10 |                     |  7
PB1      D   ----------|                     |--------  RTS
                    12 |                     | 13
PB6      K   ----------|                     |--------  CTS
                     9 |                     |  8
FLAG2    B   -----O----|                     |--------  RXD
                  |    |                     |
PB0      C   -----|    |                     |
                    15 |                     |
GND      N   ------O---|                     |
                |      =======================
                |=====================================  GND  

--
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*  nevs = Sven Goldt                           / / /" |/  "/                  * 
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