1. Introduction.
2. Atari ST 13-Pin DIN 
Pinouts.
3. Scart Euro Connector Pinouts.
4. Level Adjusting 
Resistors.
5. Atari ST to Scart Connector Wiring Assignments.
6. 
References.
 
1. 
Introduction.
================
This document discusses building a colour 
RGB Scart cable for the Atari ST.  It is relatively straightforward and no 
more complicated than connecting the right pins together.  The ST's RGB and 
SYNC signals are a little high being 1v peak-to-peak such that limiting 
resistors are recommended, they are not wholly necessary though to display a 
picture just that it may be slightly bright.
 
2. Atari ST 13-Pin DIN 
Pinouts.
===============================
The following is viewed from the 
back of the connector, ie. solder connections;
 
            
*   *   *   
*          4   
3   2   1
 
            
*   *   *   
*          8   
7   6   5
 
            
*   *   *   
*         12  11  
10   9 
                          
                  
*                     
13
 
       1 = 
Audio Output           2 = 
Composite Video
       3 = General Purpose 
Output 4 = Monochrome Detect
       5 = Audio 
In               
6 = Green
       7 = 
Red                    
8 = Plus 12-Volt Pullup
       9 = Horizontal 
Sync       10 = 
Blue
      11 = 
Monochrome            12 
= Vertical Sync
      13 = GND
 
3. Scart Euro Connector 
Pinouts.
================================
The following is viewed from the 
back of the connector, ie. solder connections;
 
          20  
18  16  14  12  10   8   6   
4   
2                
 
     
+--------------------------------------------+
      
\                                           
| 
       \   *   
*   *   *   *   *   
*   *   *   *  
|
        
\             Male 
From Behind            
|
        |  *   
*   *   *   *   *   
*   *   *   *  
|
        
|                                         
|
        
+-----------------------------------------+
 
          19  
17  15  13  11   9   7   
5   3   1
 
       1 = 
Audio Output Right     2 = Audio Input 
Right
       3 = Audio Output 
Left      4 = Audio 
GND
       5 = Blue 
GND               
6 = Audio Input Left
       7 = 
Blue                   
8 = Function Switching
       9 = Green 
GND             10 = 
Comm Data 2
      11 = 
Green                 
12 = Comm Data 1
      13 = RED/Chroma 
GND        14 = Comm Data 
GND
      15 = 
RED/Chroma            16 
= Blanking
      17 = VIDEO/Sync 
GND        18 = Blanking 
GND
      19 = VIDEO/Sync 
Ouput      20 = VIDEO/Sync 
Input
      21 = GND
 
4. Level Adjusting 
Resistors.
=============================
Resistors of 150ohms to be placed 
on the Red, Green, and Blue lines.  75ohm resistor to be placed on the 
Vertical Sync to Fast Blanking line.
 
5. Atari ST to Scart Connector Wiring 
Assignments.
==================================================
ST Signal 
Name       13-Pin 
DIN        
Scart        Scart Signal 
Name
--------------       
----------        
-----        -----------------
Audio 
Output             
1              
2+6         Audio Input 
Right+Left
Composite 
Video          
2               
20         VIDEO/Sync 
Input
Green                    
6               
11         
Green
Red                      
7               
15         Red
Plus 12-Volt 
Pullup      
8                
8         Function 
Switching
Blue                    
10                
7         Blue
Vertical 
Sync           
12               
16         Fast 
Blanking
GND                     
13               
21         GND