TeensyROM+ (PCB v0.4) — the next generation of the TeensyROM multi-function cartridge for Commodore 64/128. Every unit is a fully assembled and tested TeensyROM+, including a pre-programmed Teensy 4.1 — no soldering, no flashing, nothing to configure. Plug it in and you're ready to go.

Choose your options at checkout:

• Case — the "Exposed" low-profile design, designed and manufactured by 0ldSkull Retro, secures your TR+ into a sleek protective enclosure.
• 32GB SD Card — preloaded with a curated collection of games, SIDs, demos, and utilities, so you can take full advantage of everything TR+ can do the moment you power on.

Important: TR+ runs 100% of the standard TeensyROM feature set from the same firmware base — nothing is removed or downgraded from the original TR. TR+ simply adds a genuinely new tier of capability on top, unlocked by real bus-mastering DMA hardware that the original TR doesn't have.

TR+-Exclusive New Features:

• Kernal Replacement — load a custom KERNAL ROM image with zero hardware modification. Pick any KERNAL right from the file browser; your choice is remembered automatically.
• 512KB REU (RAM Expansion Unit) — a real REU your C64 software can detect and use. Pre-load an REU image from SD/USB, and save its live contents back out with one button press.
• Freezer Cartridge Support — Action Replay, Retro Replay and Super Snapshot V5 (PAL and NTSC) emulated natively. Freeze into it on demand with the dedicated "Alt" button.
• Remote DMA Memory Access — real-time read/write of C64 memory from an external app over Serial or Ethernet. This is the engine behind projects like c64cast (streaming video/audio straight through your C64).
• Battery-Backed Real-Time Clock — built-in coin-cell (CR1225) holder keeps the correct time through power cycles, no soldering required. No Ethernet re-sync needed once it's set.
• External Reset Detect — an external reset (C64U button, User port, etc.) drops you right back into the TR menu, same as pressing the TR button.
• Programmable Alternate Button — a second "Alt" button assignable to AutoLaunch (jump straight into your favorite title), Pause/Unpause, jump to menu, reboot, or disable.
• Full Expansion Port Test Suite — validates every cartridge port signal individually (address/data bus, DMA, BA, R/W, IRQ, NMI, and all cart control lines) — only possible with TR+'s true bus-mastering hardware.

Everything the Original TeensyROM Does (all included, none lost):

• Instant PRG/P00 loading and CRT ROM emulation from USB drive, SD card, or internal flash
• MIDI USB Host & Device — play your SID chip from a USB MIDI keyboard or DAW; Sequential, Datel/Siel, Passport/Sentech, and Namesoft MIDI cartridges emulated
• Custom ASID Player — stream .SID or .MIDI files straight from a modern PC to real SID hardware
• Ethernet internet interface — connect to Telnet BBSes, use the built-in web browser to surf/search/download, Swiftlink + 38.4k modem emulation
• NFC Launch System — tap an NFC tag for instant, old-school-cartridge-style loading
• Remote control via the cross-platform TeensyROM-Web app or Command Line Interface
• SID File Player with voice muting and speed control
• Bitmap picture viewer, PETSCII/text viewer, custom BASIC commands, Autolaunch, and more
• >100 files built-in: SIDs, games, utilities, tests, and pictures — ready to plug and play, no external media required to get started
• Firmware updates straight from SD/USB — just drop the .hex file, no special software needed

Compatibility: Compatible with C64 and C128 machines/variants — NTSC and PAL both supported. Fully validated on C64, C64C, SX-64, and C128, plus modern reproductions including the C64U/Ultimate 64, Mega65 (r5+), and Reloaded MKII.

What's included:

• Assembled & tested TeensyROM+ cartridge (PCB v0.4)
• Case, if selected — "Exposed" low-profile design by 0ldSkull Retro
• 32GB SD card, if selected — preloaded with a curated collection of games, SIDs, demos, and utilities

Firmware is actively developed and updated — free firmware updates for the life of the device, just drop the file on the SD card.

Docs, demos & community:

• Full documentation, feature guides, and firmware revision history: TeensyROM on GitHub
• Demo videos on YouTube, including an NFC reader demo
• Questions, feature discussions, and updates: come say hi on the TeensyROM Discord Server

By purchasing from me — the designer — you're directly supporting continued development of this project. Thank you!

-Travis / Sensorium

I strive to process and ship all orders the same or next day from order. Tracking info will be provided promptly.

Please feel free to contact me if you have any questions about shipping or your order in general.