Assembled CocoSOUND v0.8 board
Assembled CocoSOUND v0.8 board

CocoSOUND is a stereo sound cartridge for the TANDY Color Computer systems.  In the tradition of the TANDY Orchestra-90 sound cartridge, CocoSOUND offers additional sound creation capabilities for the TANDY Coco computer line, prividing easy access to hardware sound generators commonly used to create “chiptunes”.

CocoSOUND v0.9 PCB
CocoSOUND v0.9 PCB


  • Multi-channel (6 channels L and 6 channels R)
  • Dual General Instruments AY-3-8910/ Yamaha YM2149 Programmable Sound Generators (PSGs)
  • Dual SN76489 Digital Complex Sound Generator (DCSG) support
  • 512kB of FLASH storage (CocoFLASH-Mini compatible, 16kB bank size, Coco-3 32kB window capable)
  • Movable base addresses for both flash and CocoFLASH-Mini
  • Option to “hide” IO registers for maximum compatibility
  • 3.5″ headphone jack for line output
  • Mono (6 channels for L+R) or Stereo (6 channels per side) capability
  • 4 joystick ports (2 on DB9s, 2 on headers inside unit)
  • SEGA joystick compatible
  • 1MHz/2MHz speed selectable for PSGs (even on AY 3 8910)
  • 16 bits of digital IO (on internal joystick port headers)
  • Ability to map sound ICs in mono mode (both ICs are addressed at once, stereo mode (L is addressed at lower registers, R higher) or stereo reverse (R is lower and L is higher)
  • Coco 1-2-3 compatible

As with the TANDY Orchestra 90 system, applications must be written to take advantage of this device.


CocoSOUND is not yet available for sale.  Please let RETRO Innovations know if you have interest in developing for or obtaining this device.


Technical Details


Project Files

Frequently Asked Questions

Usage Examples