Commodore Plus/4

Released: June 1984 Original Price: $299.95

Gallery

Commodore Plus/4 computer
Commodore Plus/4 computer The Commodore Plus/4 with its built-in software suite and full-travel keyboard.
Plus/4 built-in applications
Plus/4 built-in applications The Plus/4's built-in office suite included a word processor, spreadsheet, and database.
Plus/4 advertisement
Plus/4 advertisement 1980s advertisement highlighting the Plus/4's productivity features.

Commodore Plus/4

“The Plus/4 was a computer ahead of its time. It had built-in software, a great keyboard, and excellent graphics. If only Commodore had positioned it better and given it proper software support, it might have been a real contender.” - Michael Tomczyk, Former Commodore Marketing Executive

The Commodore Plus/4 was an 8-bit home computer released in 1984 as part of Commodore’s TED series. Marketed as a productivity machine, it featured 64KB of RAM, built-in office software, and the powerful TED (Text Editing Device) chip. Despite its technical merits, the Plus/4 struggled commercially due to limited software library and competition from the wildly successful C64.

The Productivity Computer

The Plus/4 was designed to be more than just a game machine. Its name came from the four built-in productivity applications:

  1. Word Processor
  2. Spreadsheet
  3. Database
  4. Business Graphics

Why the Plus/4 Was Special

  • Built-in Software: No need to load applications from tape or disk
  • 64KB RAM: Twice the memory of the C64 (though with different architecture)
  • 121 Colors: More vibrant graphics than the C64’s 16 colors
  • Full-Travel Keyboard: Professional feel for serious work

Technical Specifications

Technical Specifications

CPU
MOS 7501/8501 @ 1.77 MHz (PAL) / 1.76 MHz (NTSC)
Memory
64 KB RAM (58 KB available) + 64 KB ROM (including built-in software)
Graphics
TED (264 series) - 320×200, 121 colors, 8 sprites, smooth scrolling
Sound
TED - 3 channels (2 square wave + noise), 4 octaves
Storage
Commodore 1531 Datasette, 1551 Floppy Drive (faster than 1541)
Ports
Cartridge, tape, serial, TV/RF, 2× joystick, user port, power
Operating System
Commodore BASIC 3.5 with built-in applications

Features and Capabilities

Built-in Software Suite

  1. Word Processor
    • Full-screen editing
    • Text formatting
    • Save/Load functionality
  2. Spreadsheet
    • 63 columns × 254 rows
    • Mathematical functions
    • Cell formatting
  3. Database
    • 900 records per file
    • Sort and search functions
    • Custom forms
  4. Business Graphics
    • Pie charts
    • Bar graphs
    • Line graphs

Graphics

  • Resolution: 320×200 pixels (40×25 text)
  • Colors: 121 colors (16 base colors × 8 luminance levels + 8 grays + 1 transparent)
  • Sprites: 8 single-color sprites (16×16 pixels)
  • Character Modes: Standard, multicolor, and extended color modes

Sound

  • Channels: 2 square wave + noise
  • Range: 4 octaves
  • Volume Control: 8 levels

The Plus/4 Experience

For Business Users

  • Productivity Suite: Everything needed for office work
  • Professional Keyboard: Full-travel keys
  • 80-Column Output: With compatible monitor
  • Fast Disk Access: 1551 drive was faster than C64’s 1541

For Programmers

  • BASIC 3.5: More commands than C64 BASIC 2.0
  • Machine Language: Full hardware access
  • Development Tools: Built-in monitor

For Gamers

  • Colorful Graphics: 121 colors
  • Smooth Scrolling: For arcade games
  • Joystick Support: Two controller ports

The Plus/4 Family

Commodore 16

  • Little brother to the Plus/4
  • 16KB RAM
  • Same TED chip
  • Lower price point

Commodore 116

  • European variant of C16
  • Calculator-style keyboard
  • Same specifications as C16

The Plus/4 Legacy

Commercial Performance

  • North America: Poor sales due to C64 competition
  • Europe: Moderate success
  • Hungary: Became popular after the fall of communism

Why It Failed

  • Software Incompatibility: Couldn’t run C64 software
  • Limited Game Library: Fewer games than C64
  • Confusing Marketing: Positioned against C64

Cult Following

  • Demoscene: Active Plus/4 demo scene
  • Homebrew: New games and applications
  • Preservation: Emulation and documentation

Notable Software

Built-in Applications

  • Word Processor
  • Spreadsheet
  • Database
  • Business Graphics

Games

  • Zenji: Puzzle game
  • Mercenary: 3D adventure
  • Tetris: Ported to Plus/4
  • The Last V8: Racing game

Development Tools

  • Turbo Assembler
  • Machine Language Monitor
  • BASIC Compiler

Technical Notes

Hardware Revisions

  1. Original Plus/4 (1984): First release
  2. Plus/4B (1985): Minor revisions
  3. C364 (prototype): Unreleased 128KB version

Common Issues

  • TED Chip: Can overheat
  • Power Supply: Original PSUs can fail
  • Keyboard: Better than C16 but still membrane-based

Modern Upgrades

  • RAM Expansions: Up to 1MB
  • Storage: SD card solutions
  • Video: RGB and HDMI mods

The Plus/4 Today

Emulation

  • VICE: Full Plus/4 emulation
  • MAME: Arcade emulation
  • FPGA: Hardware-accurate recreations

Collecting

  • Rarity: Less common than C64
  • Price: $100-$300 depending on condition
  • Desirability: Growing among collectors

Community

  • Forums: Active discussions
  • Events: Retro computing meetups
  • Development: New software and hardware

Did You Know?

  • The Plus/4 was originally going to be called the Commodore 364
  • It was the first Commodore computer with built-in software
  • The Plus/4’s BASIC 3.5 included commands for sound and graphics that the C64 lacked
  • Some Plus/4s were sold in Brazil with the TED chip running at 2MHz
  • The Plus/4 was used in Hungarian schools well into the 1990s
  • Featured in the Hungarian film “A Hét Papsajt” (1986)
  • Appeared in several Eastern European TV shows
  • Referenced in the book “On the Edge: The Spectacular Rise and Fall of Commodore” by Brian Bagnall