Atari 5200 S-video and Audio Mod

This page is made up from the schematic on the 5200 FAQ with new pictures and explenations.

Luma Decoder Circuit

The first stage of the Luma circuit decodes the digital luminance signal and mixes in the sync.

Luma Impedance Matching

The decoded luma is then passed though a emitter follower amplifier to lower the impedance to the desired level.

The chroma and audio outputs are strong enough not to need any amplification.

Parts
Where to get signals

The Below is quoted directly from the 5200 FAQ

FIXME Perhaps someone with a 5200 can take some board pics?

Most of the components do not have visible labels on the board's silkscreen, so giving component numbers is not useful. In the upper right corner of the area of the board that's covered by the shielding, there is a horizontal row of components.

             o  o  o  o  o  o  o  o  o  o  o  o  
             |  |  |  |  |  |  |  |  |  |  |  |  
             C  R3 R2 R1 D  R  R  R  R  R  R  R  
             |  |  |  |  |  |  |  |  |  |  |  |  
             o  o  o  o  o  o  o  o  o  o  o  o
                            ^  ^  ^  ^  ^  ^
                            |  |  |  |  |  `-Chroma
                            |  |  |  |  `----Luma 1
                            |  |  |  `-------Sync
                            |  |  `----------Luma 0
                            |  `-------------Luma 2
                            `----------------Luma 3

There is a row of components to the right of the GTIA (C014805) and below a cluster of inductors and transistors.

              o  o o o o o o o o o o
              |  | | | | | | | | | |
             R40 R R R R R C R R C C
              |  | | | | | | | | | |
              o  o o o o o o o o o o
                             ^
                             `--Audio