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.[1] It was produced by Frederick Electronics (of Frederick, Maryland), a subsidiary of Plantronics since 1968, and sold by Plantronics' Enhanced Graphics Products division.[2][3]

Plantronics Colorplus
Plantronics Colorplus video card.
Release date1982; 42 years ago (1982)
Manufactured byPlantronics Enhanced Graphics Products
Designed byFrederick Electronics
ArchitectureMotorola MC6845
Cards
Entry-levelPlantronics Colorplus
High-endATI Graphics Solution, Paradise AutoSwitch EGA 480
History
PredecessorCGA
SuccessorEGA

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.[4]

It uses the same Motorola MC6845 display controller as the previous MDA and CGA adapters.[1]

The original card also includes a parallel printer port.

Output capabilities

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Plantronics 320 × 200 with 16 colors graphics resolution, corrected for aspect ratio
 
Plantronics 640 × 200 with 4 colors graphics resolution, corrected for aspect ratio

CGA compatible modes:

  • 160 × 100 16 color mode (actual a text mode using , , and )
  • 320 × 200 in 4 colors from a 16 color hardware palette. Pixel aspect ratio of 1:1.2.
  • 640 × 200 in 2 colors. Pixel aspect ratio of 1:2.4
  • 40 × 25 with 8 × 8 pixel font text mode (effective resolution of 320 × 200)
  • 80 × 25 with 8 × 8 pixel font text mode (effective resolution of 640 × 200)

In addition to the CGA modes, it offers:[4]

  • 320 × 200 with 16 colors
  • 640 × 200 with 4 colors
  • "New high-resolution" text font, selectable by hardware jumper

The "new" font was actually the unused "thin" font already present in the IBM CGA ROMs, with 1-pixel wide vertical strokes. This offered greater clarity on RGB monitors, versus the default "thick" / 2-pixel font more suitable for output to composite monitors and over RF to televisions but, contrary to Plantronics' advertising claims, was drawn at the same 8 × 8 pixel resolution.


Software support

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Few software made use of the enhanced Plantronics modes, for which there was no BIOS support.

A 1984 advertisement[2] listed the following software as compatible:

  • Color-It
  • UCSD P-system
  • Peachtree Graphics Language
  • Business Graphics System[5]
  • Graph Power
  • The Draftsman
  • Videogram
  • Stock View
  • GSX
  • CompuShow (320 × 200 mode)[6]

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 (320 × 200 with 16 colors). This support was added by Planet X3 enthusiast Benedikt Freisen.[7]
  • 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.[8]
  • FastDoom, a port of Doom (1993 video game) developed by Victor Nieto, added support for ColorPlus 320 × 200 with 16 colors mode in 2021.[9]

Hardware clones

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Some third-party CGA and EGA clones, such as the ATI Graphics Solution and the Paradise AutoSwitch EGA 480,[10] could emulate the extra modes (usually describing them simply as 'Plantronics mode').

The Thomson TO16 (a PC-XT compatible)[11] and the Olivetti M19 supported Plantronics modes,[12] along with CGA.

See also

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References

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  1. ^ a b Machrone, Bill (July 1983). "Three Alternative Graphics Boards". PC Magazine. pp. 435–438.
  2. ^ a b Colorplus High Resolution Color Graphics Adapter from Plantronics. Frederick Electronics. 1984.
  3. ^ Staff writer (July 1, 1975). "Modern industries heart of area economy". The News. Frederick, Maryland: 4, 8 – via Newspapers.com.
  4. ^ a b Elliott, John (March 28, 2015). "Plantronics ColorPlus Notes". John Elliott's homepage. Retrieved 2023-04-17.
  5. ^ "Business Graphics System". PC Magazine. Vol. 4, no. 12. June 11, 1985. p. 203.
  6. ^ Berry, Bob (1993). "CompuShow v8.60 Documentation". cd.textfiles.com. Canyon State Systems.
  7. ^ Murray, David (19 February 2019). "Planet X3 is Here! And with new video modes!". The 8-Bit Guy. Retrieved 6 September 2019.
  8. ^ Freisen, Benedikt (2022-12-13), FOSS SCI Drivers, retrieved 2023-01-24
  9. ^ Nieto, Victor (Aug 16, 2021). "FastDoom 0.8.7 release notes". FastDoom at GitHub.com. Retrieved 18 November 2022.
  10. ^ Hart, Glenn (December 22, 1987). "EGA Plus Cards: VGA res for EGA monitors". PC Magazine. p. 218.
  11. ^ "Ordinateur : Le Thomson TO16 XP HD". Association MO5.COM (in French). 2007.
  12. ^ Caratteristiche techniche Personal Computer M19 (PDF) (in Italian). Olivetti. March 1986.
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