The Color Computer (affectionately known as a Coco and formerly sold by Tandy) has got to be the most underrated computer ever made. It was based on the Motorola MC6809E. The circuit used for the original Coco 1 was, almost part for part, shown in the Motorola spec sheet for the SN74LS783 - MC6883, a synchronous address multiplexer (called by Cocoists a SAM.) The third major chip in the Coco was the MC6847 Color Video Display Generator.
The Coco 1 was an 8/16 bit computer running at 0.89/1.78 MHz. The text screen was 32 letters by 16 lines in uppercase. Graphics resolution was 256x192x2 although owners quickly found that color artifacting produced by the composite video output could increase the color count by one or two orders of magnitude. Memory was limited to 32K ROM plus 64K RAM. With the Coco 3, the final version made by Tandy, the support chips were enhanced to produce a base unit with 128K RAM, 80x25 character text, 640x192x4 or 320x192x16 graphics, and RGB video output. The Coco1 did have one graphics capability that the Coco3 lacks, Semigraphics.