4-pen colour plotter for TRS-80
The CGP-115 is one of the most iconic peripherals of the TRS-80 ecosystem: it is not a printer in the classic sense, but a 4-pen plotter that literally draws on paper with real ballpoint pens that are mechanically moved. The four pens (black, red, green, blue) rotate in a turret and are selected by software command. The machine can trace curves, pie charts, bar charts, and print text in 40 or 80 column mode. Made in Japan by Alps Electric for Tandy (a clone of the famous ALPS DPG-1300/MCP-40 plotter also found rebadged as Commodore VIC-1520, Atari 1020, Mattel Aquarius, Sharp CE-150…), it sold for $249 at launch. Configuration is done via 4 DIP switches: Parallel/Serial, Scale 0/1, CR only or CR/LF, JIS or ASCII encoding. This unit is complete-in-box in remarkable condition: original '4-Pen Color Graphic Printer' box, intact polystyrene foam packaging, complete 26-1192A operation manual, original Tandy power supply and colour pens in their compartment.
The black pen no longer works
