VGA Monitor Tester PCB, 15kHz

Project Description:

This is a practical, portable monitor tester designed to check whether a given VGA monitor supports a horizontal frequency signal of 15 kHz – essential for classic retro computers such as the Amiga and Atari ST. Many modern or older CRT/LCD monitors cannot handle this mode (standard VGA is typically 31 kHz+), so the tester allows you to quickly test a monitor, for example, in a thrift store or at a flea market, without needing to bring the entire computer.

The project is an adaptation of the original idea by Planeturban (GitHub: https://github.com/planeturban/15khzvgatester), simplified for easier construction and programming. The device is battery-powered, compact, and generates appropriate test patterns on the VGA output.

Key Features:

• Generates VGA signal in 15 kHz mode.
• Multiple video patterns for testing (color bars, checkerboard, etc.).
• The "multi" version additionally supports 3 Atari modes.
• Mode switching via button (in the multi version: holding for ~10 seconds toggles between VGA and Atari modes).

Project:
https://blog.worldofjani.com/?p=8746