Connect your Commodore to the 21st century
Features include:
- ROM emulator: The perfect way to play CRT files, such as the highly recommended OneLoad64 collection.
- Instant loader: Immediately load/run program (PRG) files
- MIDI USB Host & Device, custom ASID Player: Use a MIDI keyboard, DAW, or ASID source to play your SID chip.
- Internet interface: Connect to a Telnet BBS or use the integrated web browser to surf/search/download
- Remote Control your C64 using
- NFC Launch System: The feel of old school cartridges combined with instant loading
- The feature rich (and cross-platform) TeensyROM-Web and Command Line Interface
- SID File Player with voice muting and speed control
- Bitmap Picture viewer, Text/PETSCII viewer, Custom BASIC Commands, Autolaunch, and more
- Lots of games, utilities, pics, and music built-in: no external media required to get started!
- Multiple Hardware Interfaces: SD card, USB Drive, USB Device and host Ports, Ethernet Port
- C64 Ultimate user? See this list of enhancements the TR brings to your C64U
- TeensyROM+ (PCB v0.4) adds many additional features, see this document for more details.
- Kernal Replacement — load a custom KERNAL ROM image, with no hardware modification.
- 512KB REU (RAM Expansion Unit) — a real REU your C64 software can detect and use
- Freezer Cartridge Support — Action Replay and Super Snapshot V5 (PAL and NTSC) emulated natively
- Remote DMA Memory Access — give an external app Serial or Ethernet read/write access to C64 memory
- Supported by c64cast — streaming video, audio, visualizations and much more
- Battery-Backed Real-Time Clock — a built-in coin-cell holder: TR+ can remember the correct time through power cycles
- External Reset Detect — press an external reset (C64U button, User port, etc) returns you to the TR menu
- Programmable Alternate Button — the "Alt" button is assignable to whatever's most useful
Design by Travis S/Sensorium (e-mail)
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Fully assembled/tested TeensyROM+ units are available via my Lectronz Shop, or via Tindie or eBay.
Case/enclosures are available for sale with a new unit (see links above), or download and print at home.
Please consider joining us in the TeensyROM Discord Server to meet other TeensyROM users, ask questions, provide thoughts/input/feedback, etc.
- TeensyROM Feature Details
- Links to detailed documentation
- Demo Videos
- Hardware/PCB Design
- Compatibility
- Inspiration and Thank-Yous
- Pictures/screen captures
Compatible with C64 and C128 machines/variants, NTSC and PAL supported.
- USB thumb Drive
- SD card
- Teensy Internal Flash Memory
- Transfer directly from PC using TeensyROM-Web (cross-platform, recommended) or the TeensyROM UI (Windows desktop)
- See supported file details here
- NFC Loading system available to quickly select/load with NFC tags.
- Play your SID with a USB MIDI keyboard!
- Use with popular software such as Cynthcart, Station64 etc, or the included MIDI2SID app
- 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
- Stream .SID or .MIDI files from a modern computer directly to your Commodore machine SID chip!
- Play MIDI files out of your PC into C64 apps such as Cynthcart or the MIDI2SID app
- Stream .SID files out of your PC using the ASID MIDI protocol to hear any SID file on original hardware.
- Connect to your favorite 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
- Just drop the .hex file on an SD card or USB drive, no need for extra software to update.
Key parameters (startup, Ethernet, timezone, etc.) are stored in internal EEPROM and retained after power down.
- Usage Documents
- SW Release notes/development
- Hardware & PCB Related
- This YouTube Playlist contains all the latest TeensyROM demo videos, such as:
- Real-time video/audio capture of menu navigation and loading/running/emulating various programs/cartridges
- Demo using Cynthcart and Datel MIDI emulation to play with a USB keyboard
- MIDI ASID Demo: Stream .SID & .MIDI files directly to your C64/SID
- Web Browser and internet file download demo
- SID Player and Picture viewer demo
- TeensyROM compatability has been fully validated on many different NTSC and PAL machines: C64, C64C, SX-64, and C128 as well as modern reproductions such as the C64U, Ultimate 64, EVO64, Mega65 (r5 and higher), and Reloaded MKII
- The early "prototype" version of breadbin (PCA 326298 w/ 5 pin video) has a known issue with the reset circuit that must be corrected to be compatible with the TeensyROM and other fastload cartridges. See this post or this video for instructions on how to correct this issue.
PCB 0.2/0.3 Component selection was done using parts large enough (SOIC and 0805s at the smallest) that any soldering enthusiast should be able to assemble themselves. Since high volume production wasn't necessarily the vision for this device, 2 sided SMT was used to reduce the PCB size while still accommodating larger IC packages.
The original TR (v0.2/0.3) — publicly self-buildable today; see assembly instructions.
Beginning with PCB v0.4 (TeensyROM+) the package sizes are reduced (TSSOP and 0603 passives) to allow additional needed circuitry and single sided manufacturing.
A note about overclocking The Teensy 4.1 is slightly "overclocked" to 816MHz from FW in this design. Per the app, external cooling is not required for this speed. However, in abundance of caution, a heatsink is specified in the BOM for this project. In addition, the temperature can be read on the setup screen of the main TeensyROM app. The max spec is 95C, and there is a panic shutdown at 90C. In my experience, even on a warm day running for hours with no heatsink, the temp doesn't exceed 75C.
- Heather S: Loving wife, continuous encourager, saintly patience
- MetalHexx: Big picture ideas, TeensyROM Web, UI and CLI, testing, friendship
- Avrilcadabra: Musician, experimenter, provider of ideas and feedback
- Paul D aka Digitalman: Thought provoker, promoter, Maker, and tester extraordinaire
- Stefan Wessels: Cartridge case design
- StatMat: NFC Scanner idea, Fast boot code, OneLoad64 creation
- Giants with tall shoulders: SID/SIDEKick, KungFu Flash, VICE Team
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See the media folder for more pics and screen shots.











