# Atari 7800 Expansion

     Gnd   +5v  CVideo MLum0 Mlum3 Blank OscDis ExtMen Gnd
    --1-- --2--  --3-- --4-- --5-- --6-- --7-- ---8-- --9--

    -18-- -17--  -16-- -15-- -14-- -13-- -12-- --11-- -10--
     Gnd  Audio   Rdy   MCol MLum2 MLum1 Msync  Clk2  ExtOsc

(at the Atari)

UNKNOWN CONNECTOR at the Atari.

Pin | Name | Description
--- | --- | ---
1 | GND | Ground
2 | +5V | +5 VDC
3 | CVIDEO | Input to RF modulator (Video+Audio)
4 | MLUM0 | Maria Luminance Bit 0
5 | MLUM3 | Maria Luminance Bit 3
6 | BLANK | Blanking output
7 | OSCDIS | Disable 14.31818 MHz Master Clock
8 | EXTMEN | External Maria Enable Input
9 | GND | Ground
10 | EXTOSC | External clock to replace Master Clock
11 | CLK2 | Phase 2 Clock from the 6502
12 | MSYNC | Maria Composite Sync
13 | MLUM1 | Maria Luminance Bit 1
14 | MLUM2 | Maria Luminance Bit 2
15 | MCOL | Maria Color Phase Angle
16 | RDY | Input to the 6502
17 | AUDIO | Audio
18 | GND | Ground

Contributor: Joakim Ögren

Source:
Classic Atari 2600/5200/7800 Game Systems FAQ - Pinout by Harry Dodgson

Copyright © The Hardware Book Team 1996-2001.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2001-06-08