Plantronics Colorplus
Enhanced CGA card with double memory and extra color modes.
The Plantronics Colorplus, a graphics card for IBM PC computers, launched in 1982. It extended the existing CGA standard, working with the same 4-bit digital TTL RGBI monitors and offering the same base resolutions. Manufactured by Frederick Electronics (a Maryland-based Plantronics subsidiary since 1968), it was sold through Plantronics' Enhanced Graphics Products division. The card doubled the standard CGA memory to 32 KB, allowing two extra graphics modes: 16 colors at 320×200 resolution, or 4 colors at 640×200 resolution. It relied on the same Motorola MC6845 display controller used in earlier MDA and CGA adapters, and included a built-in parallel printer port.
The Colorplus could run all standard CGA modes: 160×100 in 16 colors (a text mode using block characters), 320×200 in 4 colors from a 16-color palette (with a 1:1.2 pixel aspect ratio), 640×200 in 2 colors (1:2.4 aspect ratio), plus 40×25 and 80×25 text modes with an 8×8 pixel font. Its enhanced modes offered 320×200 in 16 colors and 640×200 in 4 colors. A hardware jumper could select a "new high-resolution" text font, which was actually the unused thin font already present in IBM CGA ROMs—featuring 1-pixel-wide strokes for better clarity on RGB monitors, though still at the same 8×8 resolution as the default thick font.
Few programs supported the Colorplus's enhanced modes, as no BIOS routines existed for them. A 1984 advertisement listed compatible software including Color-It, UCSD P-system, Peachtree Graphics Language, Business Graphics System, Graph Power, The Draftsman, Videogram, Stock View, GSX, and CompuShow (in 320×200 mode). Modern additions include Planet X3 (2019, with 320×200 16-color support added by enthusiast Benedikt Freisen), Attack of the Petscii Robots (2020, ported to MS-DOS with Colorplus support), updated drivers by Freisen (2021) for Sierra's Creative Interpreter adventure games, and FastDoom (2021, a Doom port by Victor Nieto) supporting 320×200 16-color mode.
Some third-party CGA and EGA clones—such as the ATI Graphics Solution and Paradise AutoSwitch EGA 480—could emulate these extra modes, often labeling them simply as "Plantronics mode." The Thomson TO16 and Olivetti M19 also supported Plantronics modes alongside standard CGA.
Quick Facts
- Designfirm
- Frederick Electronics
- Manufacturer
- Plantronics Enhanced Graphics Products
- Entry
- Plantronics Colorplus
- Highend
- ATI Graphics Solution, Paradise AutoSwitch EGA 480
- Predecessor
- CGA
- Successor
- EGA
- Architecture
- Motorola MC6845
Facts from the source article.
Lore & Background
The Plantronics Colorplus was produced by Frederick Electronics of Frederick, Maryland, a subsidiary of Plantronics since 1968, and sold by Plantronics' Enhanced Graphics Products division. It uses the same Motorola MC6845 display controller as the previous MDA and CGA adapters. The original card also includes a parallel printer port. In addition to standard CGA-compatible modes, it offers 320×200 with 16 colors and 640×200 with 4 colors, enabled by its 32 KB of memory (double the 16 KB of standard CGA). It also provides a 'new high-resolution' text font selectable by hardware jumper, which was actually the unused 'thin' font already present in the IBM CGA ROMs, with 1-pixel wide vertical strokes. This font offered greater clarity on RGB monitors versus the default 'thick' font, but was drawn at the same 8×8 pixel resolution.
Reader's Guide
The Plantronics Colorplus is significant as an early graphics enhancement for IBM PC computers, offering higher color depth than standard CGA without requiring a different monitor. Its additional 16 KB of memory allowed 16 colors at 320×200 resolution or 4 colors at 640×200, modes that were rarely used due to lack of BIOS support. Few software titles were listed as compatible in a 1984 advertisement, including Color-It, UCSD P-system, Peachtree Graphics Language, Business Graphics System, Graph Power, The Draftsman, Videogram, Stock View, GSX, and CompuShow (320×200 mode). Contemporary software has added support: Planet X3 (2019) was the first video game known to have Colorplus support, followed by Attack of the Petscii Robots (2020). Updated drivers in 2021 added Colorplus support to Sierra's adventure games running on Sierra's Creative Interpreter, and FastDoom (a port of Doom) added support for the 320×200 16-color mode in 2021. Some third-party CGA and EGA clones, such as the ATI Graphics Solution and the Paradise AutoSwitch EGA 480, could emulate the extra modes, often described as 'Plantronics mode'. The Thomson TO16 and Olivetti M19 also supported Plantronics modes.
Did You Know?
- The Plantronics Colorplus was first sold in 1982 and produced by Frederick Electronics, a subsidiary of Plantronics since 1968.
- It has twice the memory of a standard CGA board (32 KB vs. 16 KB), enabling 16 colors at 320×200 or 4 colors at 640×200.
- The 'new high-resolution' text font was actually the unused 'thin' font already present in IBM CGA ROMs, drawn at the same 8×8 pixel resolution.
- The first video game known to have Colorplus support was Planet X3, released in 2019 by American YouTuber David 'The 8-Bit Guy' Murray.
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