The Plantronics Colorplus
was a graphics card
for IBM PC
computers, first sold in 1982
. It was a superset of the then-current CGA
standard, using the same monitor standard and providing the same pixel resolutions.
The Colorplus had twice the memory of the CGA (32k, compared to 16k). The additional memory could be used in graphics modes to double the color depth, giving two additional graphics modes - 16 colors at 320x200 resolution, or 4 colors at 640x200 resolution. Few programs made use of these modes, for which there was no BIOS support.
Some third-party CGA and EGA clones, such as the ATI Graphics Solution and the Paradise EGA, could emulate the extra modes (usually describing them simply as 'Plantronics mode').