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All source code for the CGA Compatibility Tester is now online at github. The most recent download should always be available there. If you find any issues, please submit them and I'll get to them when able.


The CGA Compatibility Tester, as its name implies, is a program that benchmarks and stresses nearly every capability of the IBM Color Graphics Adapter (CGA). This can be used to:

Full documentation is included in the .zip file (see below for download) as "cga_comp.txt". Please consult the documentation for more information.

The following tests are included:

Adapter memory speed benchmarks:

Color Select and Mode Control Register tests:

Textmode manipulation:

Monitor Calibration:

MC6845 CRTC programming:

Reference Video

To provide a reference to how the tester works with a real 100% IBM CGA card and monitor, a Full-D1 MPEG-2 video of some of the more demanding tests in an earlier version of the program is available courtesy of The Internet Archive. It is highly recommended to watch the video before attempting to use the tester, so that you can have an idea of what some of the more demanding tests are supposed to look like. (The video is somewhat outdated as it doesn't cover all of the tests present in the current version, but it covers the more important ones.)

Here is a streaming version of that video, for the curious:

Additional References:

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This page's content was last modified on Sep 10, 2018 10:49 pm.
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