Commodore Plus/4: The productivity-focused machine

My name is Gabor – a real fan of Commodore Plus/4 – who created this website for others like me. This is about showcasing the work of talented people who have developed something interesting for keeping long live Commodore Plus/4 and its awesome worldwide community.

The Commodore Plus/4 is an 8-bit home computer released by Commodore International in 1984, primarily designed for business and office users but also popular among home users due to its affordable price. As part of the Commodore 264 series, alongside the Commodore 16 and 116, the Plus/4 was positioned as a successor to the iconic Commodore 64, though it differed significantly in many aspects.

Technical Specifications

The Commodore Plus/4 featured a compact, sleek design with an integrated keyboard, giving it a professional appearance. Its key technical specifications include:

• Processor: MOS Technology 7501 (or 8501), running at 1.76 MHz (NTSC) or 1.77 MHz (PAL), an enhanced version of the 6510 processor.
• Memory:
  • 64 KB RAM (with 60 KB available for BASIC).
  • 32 KB ROM, containing BASIC 3.5 and built-in software.
• Graphics: TED (Text Editing Device) chip, supporting a 320×200 pixel resolution with 121 color shades (16 colors, 8 brightness levels).
• Sound: 2-channel mono sound generated by the TED chip, less advanced than the C64’s SID chip.
• Storage: Support for external 1541 floppy drives or C2N cassette units (Datassette).
• Connectors:
  • Two joystick ports.
  • RF modulator for TV output.
  • Serial port, cartridge port, and a proprietary “Mini-DIN” connector for peripherals.
• Keyboard: 67-key full-size keyboard with four dedicated function keys.

Built-in Software

The Plus/4’s most innovative feature was its built-in office software suite, 3-Plus-1, which included:

• Word processor.
• Spreadsheet.
• Database manager.
• Graphics program. Stored in ROM, these applications were instantly accessible upon powering on the machine, a significant advantage over competitors at the time.

Software and Game Library

The Plus/4 had limited compatibility with the Commodore 64 due to different processors and chips, but it had its own software ecosystem. However, it lagged behind the C64 in gaming due to the TED chip’s weaker sprite handling and inferior sound quality. Popular games included Fire Ant, Mercenary, and Jack Attack. The BASIC 3.5, however, was more advanced than the C64’s BASIC 2.0, making it appealing for programmers.