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The TeensyROM Multifunction Cartridge for the C64 & C128, designed by Travis Smith. This plug and play cartridge is designed for use with the Commodore 64 and 128, and offers a multitude of functions in one sleek device. Whether you're looking to load multiple programs or games with ease, the TeensyROM cartridge has got you covered. Say goodbye to the hassle of swapping cartridges - this multipurpose cart is the perfect solution for any C64 enthusiast. Upgrade your computing experience with the TeensyROM Cart and unlock the full potential of your Commodore 64 system.


 - Superfast Loader

 - MIDI Connectivity

 - Connect to the Internet

 - Use MicroSD or USB


TeensyROM is a ROM emulator, super fast loader, MIDI Host+Device and Internet interface cartridge for the Commodore 64 & 128, based on the Teensy 4.1


This is a fully assembled and tested TeensyROM board, including a pre-loaded Teensy 4.1.   It has a selection of built-in utilities and games, ready to plug and play! 


TeensyROM is an open source project, and offered here with the kind permission of the developer.


- PCB has ENIG (Electroless Nickel Immersion Gold) finish

- USB flashdrive included. 

- 8GB MicroSD included (Supports up to 32GB)


TeensyROM Main Features:

Compatable with C64 and C128 machines, NTSC and PAL supported

TeensyROM compatability has been fully validated on many different NTSC and PAL machines: C64, C64C, SX-64, and C128


Super Fast Loading of .CRT .PRG & .P00 Files directly from:

  • USB Thumb Drive
  • Micro SD card
  • Teensy Internal Flash Memory
  • Transfer directly from PC (Windows app included)
  • NFC Loading system available to quickly select/load with NFC tags (Tapto)


MIDI in/out via USB Host Connection:

  • Play your SID with a USB MIDI keyboard!
  • Use with popular software such as Cynthcart, Station64 etc
  • Supports all regular MIDI messages in and out
    • Can use your C64 to play a MIDI sound capable device.
  • Sequential, Datel/Siel, Passport/Sentech, and Namesoft MIDI cartridges emulated
  • Use a USB Hub for multiple instruments+thumb drive access


MIDI in via USB Device Connection:

  • Stream .SID or .MIDI files/data from a modern computer directly to your Commodore's SID chip!
  • Play MIDI files out of your PC into C64 apps such as Cynthcart or the MIDI2SID app
  • Play .SID files out of your PC using the ASID MIDI protocol to hear any SID file on original hardware.


Internet Communication via Ethernet Connection

  • Surf the web with built-in web browser, including URL bookmarks and high speed file downloads
  • Connect to your favourite C64/128 Telnet BBS
  • Use with released software such as CCGMS, StrikeTerm2014, DesTerm128, etc
  • Swiftlink cartridge + 38.4k modem emulation
  • Send AT commands from terminal software to configure the Ethernet connection
  • Sets C64 system time from internet


Firmware Updates Directly from SD card or USB Thumb-drive

  • Just drop the .hex file on an SD card or USB drive, no need for extra software to update.

Key parameters stored in internal EEPROM

  • Startup, Ethernet, timezone, etc retained after power down.


Also Available:

TeensyROM 3D Printed Case

NFC Reader/Writer


TeensyROM Multipurpose Cart for C64 & C128



  • TeensyROM designed by Travis S/Sensorium is a ROM emulator, super fast loader, MIDI Host/Device, Internet interface cartridge and more for the Commodore 64 & 128, based on the Teensy 4.1


    More Info at:

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