Texas Instruments SN76430N Video Generator

The CyberVision 2001 utilizes a TI SN76430N Sync and Video Generator chip at U80, tied to a 3.58MHz crystal, to handle all of its video processing. Original datasheets have not yet been uncovered for this chip, which was one in a series of TI “Universal Game Chip” initiatives in the 1970s. The only known summary of this chip’s operations appears in the book “How to Repair Video Games” by Robert Goodman, 1978. The content is transcribed below:



  • Provides color composite video signal.
  • Produces horizontal and vertical sync pulses.
  • Built-in video summing section.


The SN76430N utilizes low-power Schottky TTL technology to provide a color composite video output signal, video summing, and horizontal and vertical synchronization pulses in a complete video game system. Clock reference is a 3.58 MHz crystal. Of course, the chip is TTL and CMOS compatible.


The circuit generates horizontal and vertical sync pulses from a 3.58 MHz internal oscillator. The chip also contains a video summer accepting video information from five video inputs (pins 16, 17, 18, 19, and 20). A composite video waveform is generated containing horizontal and vertical blanking, horizontal and vertical sync, color burst background video information, spot video information (players, walls, balls, score, etc.), and serration pulses.

Color burst begins at the end of horizontal sync and continues for 14 cycles of the subcarrier (3.58 MHz), and is present on all lines except those where serration pulses are present. The color yellow is assigned to any information fed to video inputs 16 and 17. The color phase is the same as burst. Light-blue color is assigned to any information fed to video input pins 19 and 20. The information fed to pin 18 is yellow when pin 1 is a logic zero, matching the yellow assigned to pins 16 and 17. When pin 1 is switched to a logic one, the information at 18 is changed to the light-blue color, matching the light-blue color assigned to pins 19 and 20.

Background color is adjustable by raising or lowering the DC level into pin 3, with an adjustment of about 180° possible. A background color inversion of 195° from pin 3 setting may be obtained by applying a logic one to the background color invert pin (pin 15).

Horizontal and vertical sync outputs are totem-pole type, and compatible with standard TTL and CMOS circuits. Horizontal sync pulse width is approximately 4.85 μs. Vertical sync pulse width is three horizontal sync pulses. Vertical blanking begins 3 horizontal lines before vertical sync, and continues for 19 horizontal lines. Horizontal blanking (generated externally, and applied at pin 8) and vertical blanking will eliminate video signals, excluding burst. The fact that it purportedly generates simple composite out makes for an inviting prospect toward composite modding the set once it’s operational again.





From the late-1970s through early-1980s, Texas Instruments distributed a variety of ICs designed primarily for hobbyists to put together standalone electronic games. The SN7430N was part of this build-up. It is uncertain how many were sold to the public, or in what territories. Advertisement for them appeared in various catalogs outside of the United States. Below is a listing of these chips:

SN76423NAutomatic Random English
SN76424NWall Generator
SN76425NSystem Regulator and Sync Generator
SN76426NDual Character Generator
SN76427NWall Ball Generator
SN76428NVideo Game Logic
SN76429NHockey/Tennis/Hand Ball Game Logic
SN76430NSync Generator / Color Generator / Video Summer
SN76431NComplex Character Position Controller
SN76432NHockey/Tennis/Handball Character
SN76440NSpace War Game Logic Complex Character
SN76442NRace Car / Rocket Ship / Universal Man Character
SN76443NComplex Character Generator
SN76444NRocket Ship / Hockey / Tennis
SN76445NGun Fighter / Universal Man Character
SN76446NExploding Rocket Character
SN76449NExploding Helicopter Character
SN76460NZero to Win at 20 Digital
SN76477NComplex Sound Generator
SN76483NSpace War Obstacles Generator
SN76484NSpace War Switching Logic

Last Updated on March 9, 2023.

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