What Is CGA Composite Mode in the Ultima 2 Upgrade?

CGA Composite Mode is a graphics option in The Exodus Project's Ultima 2 Upgrade that reinterprets the game's original CGA pixel patterns so they display as smoother, more natural colors instead of harsh magenta-and-black. It targets players running the upgraded Ultima 2 who want the early graphics to look closer to how they appeared on composite monitors, rather than the blocky RGB output most modern displays produce. The feature was the main graphics goal behind the next release of the upgrade, and the project author reports it was completed by reusing an algorithm written for the Ultima 3 Upgrade.

Why the original CGA modes looked poor

The project author describes the CGA modes of Ultima 2 and 3 as "pretty horrible to look at" and names that as the primary motivation for starting the project roughly 20 years earlier. The key point is that these modes were never really intended to be viewed the way most people see them now. On the original hardware and displays, the same pixel patterns could resolve into different colors than a modern RGB rendering shows.

How composite mode changes the output

CGA Composite Mode works by blending alternating pixel patterns into a single perceived hue. The project's own example uses the water tiles:

• Water: alternating magenta-and-black pixels appear as a smooth, deep blue.
• Brick tiles in towns and castles: alternating the pixels in the opposite order (black then magenta) produces the red used on those tiles.

So the mode does not add new artwork. It changes how existing alternating pixel sequences are interpreted, which is why the same tile data can yield blue water and red brick depending on pixel order.

A concrete way to think about it

Take a water tile made of alternating magenta and black pixels. Under a straight RGB reading, you see the alternation as noise or a harsh pattern. Under composite interpretation, the alternation averages into a deep blue. Reverse the order to black-then-magenta and the same averaging logic yields red. That is the mechanism the upgrade relies on.

Where it fits in the upgrade

CGA Composite Mode is a visual upgrade, distinct from gameplay changes in the same release. For comparison, the same Ultima 2 Upgrade version also adds:

The Stat Choice feature is explicitly described as toggle-able through configuration, which tells you the upgrade separates gameplay toggles from visual ones. The CGA Composite Mode is presented as the headline visual feature of that release.

What to expect if you try it

• You need the Ultima 2 Upgrade itself. The mode ships as part of the upgrade release, available from the project's download section, not as a standalone patch.
• Expect color changes, not new graphics. Water becomes deep blue and town/castle brick becomes red; the underlying tiles are the same.
• It is aimed at the CGA-era look. If you are comparing against the raw CGA output, composite mode is the intended "correct" presentation the author had in mind.

The project page does not state pricing or login requirements for downloads, so check the download section directly for access details.