VGA to SCART

This pages describes a vga to scart adapter and a working setup with xFree/Xorg and old 80's style TV. The ususal disclaimer and policy applys.

VGA                                                SCART

 1 -O------------------------------------------O- 15 R
 2 -O------------------------------------------O- 11 G
 3 -O------------------------------------------O-  7 B
 
 6 -O------------------------------------------O- 13 R Gnd
 7 -O------------------------------------------O-  9 G Gnd
 8 -O------------------------------------------O-  5 B Gnd
 
 5 -O-+
      |
11 -O-+

Connector --------------------------------------O- 21 Connector
shell                                                 shell
 
 14 -O------------------------+ 
-VS                           |
                              |
                          |  /
        +-----+           |/
 13 -O--+ 3k3 +-----*-----|     BC 548 B
-HS     +-----+     |     |\
                    |     |  \|
                    |        -|     +-----+
                    |         *-----+ 68  +-----O- 20
                    |         |     +-----+       -CS
                   +++       +++
                   | |       | |
                   | |       | |
                   +++       +++
                    |         |
 10 -O--------------*---------*-----------------O- 17
Gnd                1k2       820                  Gnd


*optional*: combine grounds

5,6,7,8,Shell ------------------------------------ 5,9,13,17,21  (grounds)

*optional*: hardcode TV mode - some //modern// TVs allow those modes 
to be switched via OSD, or autodetection. I needed to hardwire those for my
old 80's arcade - TV.

+12V <------------------------*-----------------O- 8
                              |
                              |     +-----+
                              *-----+ 560 +-----O- 16
                                    +-----+       

GND  <------------------------------------------O- 17,18

You can use any general purpose low frequent low power Si NPN transistor instead of the BC 548 B The resistors are all standard 250 mW carbon film resistors;

 68 = 68 Ohm
560 = 560 Ohm
820 = 820 Ohm
1k2 = 1200 Ohm
3k3 = 3300 Ohm

Notes:

• The link between 5 (Gnd) and 11 (Mid0) tells your VGA card that your `monitor' is colour.
• The R-, G- and B grounds are in fact shields (The R-, G- and B wires are in fact little coaxes). The same goes for the `-CS' wire.
• The connector shells are connected to a common shield screening all wires and coaxes inside the cable.
• If you use a female SCART connector, use pin 19 for -CS.

• 12 Volt on scart pin 8 selects AV mode.
• 3 Volt on pin 16 select RGB (instead of composite)

X11 XF86Config-4 or xorg.conf

Section "Device"
      Identifier      "GFX"
#     Driver          "mga"
      Driver          "nv"
      BusID           "PCI:1:5:0"
EndSection

Section "Monitor"
      Identifier      "TV"
      HorizSync       10-20
      VertRefresh     40-60

      ModeLine "TV" 18.00 936 968 1056 1152 576 580 583 625 interlace -hsync -vsync

EndSection

minimum pixel clock of 18MHz.

Clock range:  17.75 to 250.00 MHz