The Plantronics Colorplus is a graphics card for IBM PC computers, first sold in 1982. It implements a superset of the then-current CGA standard, using the same monitor standard (4-bit digital TTL RGBI monitor) and providing the same pixel resolutions. It was produced by Frederick Electronics (of Frederick, Maryland), a subsidiary of Plantronics since 1968, and sold by Plantronics' Enhanced Graphics Products division.

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 resolution, or 4 colors at resolution.

It uses the same Motorola MC6845 display controller as the previous MDA and CGA adapters.

  • Graph Power
  • The Draftsman
  • Videogram
  • Stock View
  • GSX
  • CompuShow ( mode)

Some contemporary software has added support for Plantronics modes:

  • Planet X3, released by American YouTuber David "The 8-Bit Guy" Murray in 2019, was the first video game known to have Colorplus support ( with 16 colors). This support was added by Planet X3 enthusiast Benedikt Freisen.
  • Attack of the Petscii Robots by American YouTuber David "The 8-Bit Guy" in 2020, ported to MS-DOS computers with a graphics mode providing support for Plantronics Plus.
  • Benedikt Freisen produced updated drivers in 2021 that add Colorplus support to Sierra's adventure games that ran on Sierra's Creative Interpreter.
  • FastDoom, a port of Doom (1993 video game) developed by Victor Nieto, added support for ColorPlus with 16 colors mode in 2021.

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) and the Olivetti M19 supported Plantronics modes, along with CGA.

See also

  • Tandy Graphics Adapter, a graphics hardware system with similar capabilities. <!-- TGA, or CGA Plus, is a chip on (Tandy or IBM PCjr) motherboards; it was never sold on a plug-in adapter board.-->
  • Quadram Quadcolor
  • Orchid Graphics Adapter
  • Hercules Graphics Card
  • Olivetti M19
  • Thomson TO16

References

  • "+COLORPLUS Shatters The Mold.", an original advertisement.
  • A USENET posting describing the Plantronics Colorplus
  • The technical documentation for the Paradise EGA chipset in the Amstrad PC-1640 describes its Plantronics compatibility mode.