TeensyRom C-64 / C-128

The TeensyROM Multifunction Cartridge for C64 & C128 was developed by Travis Smith . Designed for use with the Commodore 64 and 128, this plug-and-play cartridge offers a variety of features in a single, sleek device. Whether you want to effortlessly load multiple programs or games, the TeensyROM cartridge is the right choice. Say goodbye to the hassle of replacing cartridges – this versatile module is the perfect solution for any C64 enthusiast. Enhance your computing experience with the TeensyROM cartridge and unlock the full potential of your Commodore 64 system.

TeensyROM is a ROM-Emulator, Super-Fast-Loader, MIDI Host+Device and Internet-Interface-Cartridge for the Commodore 64 & 128, based on Teensy 4.1.

This is a fully assembled and tested TeensyROM board, including a pre-installed Teensy 4.1, with a selection of built-in utilities and games ready to use(plug and play)!

TeensyROM is an open source project.

Scope of delivery:

• The TeensyRom cartridge circuit board(PCB) has an ENIG finish.
• Current firmware 0.6.8 from 25.7.2025
• 3D print housing in any color.
• Optional: MicroSD card with 8GB (supports up to 32GB)

TeensyROM Main features:

• Compatible with C64 and C128 machines, NTSC and PAL are supported
• TeensyROM compatibility has been fully validated on many different NTSC and PAL machines: C64, C64C, SX-64 and C128

Super fast loading of .CRT, .PRG and .P00 files directly from:

• USB stick
• Micro SD card
• Internal Teensy flash memory
• Direct transfer from PC (Windows app included)
• NFC charging system available to quickly select/charge 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-enabled device.
• Sequential, Datel/Siel, Passport/Sentech and Namesoft MIDI cartridges emulated
• Use a USB hub for multiple instruments + access to the flash drive

MIDI In via USB device connection:

• Stream .SID or .MIDI files/data from a modern computer directly to the SID chip of your Commodore!
• Play MIDI files from your PC in C64 apps like Cynthcart or the MIDI2SID app
• Play .SID files from your PC via the ASID MIDI protocol to hear any SID file on original hardware.

Internet communication via Ethernet connection

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

Firmware updates directly from the SD card or USB stick

• Simply place the .hex file on an SD card or USB drive; no additional software is required for updating.
• Important parameters are stored in the internal EEPROM
• Start, Ethernet, time zone etc. are retained after switching off.