Plantronics Colorplus

The Plantronics Colorplus is a graphics card for IBM PC computers, first sold in 1982. It is a superset of the then-current CGA standard, using the same monitor standard and providing the same pixel resolutions. It was produced by Frederick Electronics, of Frederick, Maryland.
The "Colorplus" has twice the memory of a standard CGA board (32k, compared to 16k). The additional memory can be used in graphics modes to double the color depth, giving two additional graphics modes—16 colors at 320×200 resolution, or 4 colors at 640×200 resolution.
It uses the same Motorola MC6845 display controller as the previous MDA and CGA adapters.
The original card also includes a parallel printer port.
Output capabilities.
CGA compatible modes:
In addition to the CGA modes, it offers:
Software support.
Few programs made use of these modes, for which there was no BIOS support.
A 1984 advertisement listed as compatible software Color-It, UCSD P-system, Peachtree Graphics Language, Business Graphics System, Graph Power, The Draftsman, Videogram, Stock View and GSX. In addition, Canyon State Systems CompuShow supports the 320×200 mode.
"Planet X3", released by American YouTuber David "The 8-Bit Guy" Murray in 2019, is the only video game known to have Colorplus support.
Hardware Clones.
Some third-party CGA and EGA clones, such as the ATI "Graphics Solution" and the Paradise "AutoSwitch EGA 480", could emulate the extra modes (usually describing them simply as 'Plantronics mode'). The Thomson TO16 (a PC-XT compatible) had the Plantronics modes integrated on the motherboard, along with CGA.