Comet+ Prototype Boards Are + IN and I'm Hacking!
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Wi-fi + Storage + Disk Drive Hybrid for Commodore.

Comet+ Features.


The Comet+ combines mass-storage with the Internet in a single device, while providing flexibility to customize it to your specific needs.

  • Wi-fi (the first commercially available wi-fi 802.11b/g device for Commodore computers)
  • IEC to Internet (LOAD files directly from the Internet over the serial / IEC bus)
  • Access any Internet destination
  • Micro SD card with FAT-32 file system - access D64s like a disk drive
  • Emulated disk drive (device # selectable to access D64s or other content stored on the on-board SD card or cached in the flash RAM)
  • User port to Internet at 38.4K baud (faster speeds are expected, utilizing the C64s ability to do parallel data transfers)
  • Internet BBS capable (no external computer required), compatible with existing BBS systems and terminal programs
  • Open-source firmware, based on the Arduino development system
  • Customizable hardware and firmware (on-board breadboard for adding components and creating new peripherals)
  • Standard RS-232c DE9 interface to communicate with other RS-232 devices
  • RS-232 port can be used by other retro computers, offering all of same the Comet+ features and capabilities
  • Arduino controlled: Create your own sketches to access the different parts individually or combine to make your own peripheral (see the ideas list for possible configurations)
  • Comet+ can be used stand-alone as a disk drive, or an Internet Modem or can be plugged in to the User Port on the C64, C128, Vic-20, Plus/4 or Commodore 16 for additional use and functionality
  • 4MB on-board user-programmable flash RAM (permanently store D64s or other data)
  • 64K on-board user-programmable static RAM
  • 4K on-board EEPROM
  • RAM programmable via the IEC or User ports
  • On-board TCP/IP stack (no need to use a software solution)
  • Compatible with multiple Commodore or other retro computers (IEC Bus, User Port, RS-232 port, and headers to comm lines for custom wires/ports)
  • Compatible with other Serial-to-Ethernet software
  • Compatible with the original Comet64 specification
  • Affordable upgrade option from the Comet64 Internet Modem

On-board Hackery.

On-board Hackery

If you like experimenting with electronics or tinkering with microcontrollers, the Comet+ comes with a breadboard so that additional peripherals may be created or additional interfaces may be added. The following areas are available for breadboarding and interfacing to the components on the Comet (note: some items may change for the better, as the final specification is not yet complete):

  • +3.3v, +5v and GND poles
  • 2 User I/O lines tied directly to Arduino
  • 2 User LEDs on board
  • 2 User GPIO (General-purpose Input/Output) lines, controlled via SPI
  • 8 GPIO lines (also wired to user port)
  • 4 GPIO lines (also wired to logic-level side of RS-232 port)
  • User Port handshaking lines
  • RX, TX, CTS, RTS lines from Arduino (also wired to Internet module via jumpers)
  • SPI MOSI, MISO and CLK lines available at poles (so you can add other SPI devices to the breadboard)

In addition to the external lines, the user has complete control over all of the on-board peripherals via the ATMEGA microcontroller (MCU). New firmware or user-created Arduino "sketches" may be uploaded directly to the MCU via the Commodore 64 or other external device.

The MCU has full access to the following on-board modules and interfaces:

  • SPI Interface, which controls the FLASH RAM, SRAM, SD card and GPIO (along with any user-created SPI devices)
  • RS-232
  • User Port
  • IEC Bus
  • Internet module
  • User input switch
  • User I/O lines


The Comet64 Internet Modem was the first of my Internet devices, which provides simple Internet connectivity over the User Port, allowing users to connect to Telnet BBS servers, Q-Link Reloaded and CommodoreServer. It also has an RS-232c port for connecting to other RS-232 devices, such as a home computer. It has gone through four board revisions, getting better in each one.

Now, the Comet+ is the next generation and natural evolution of the Comet64 Internet Modem, providing a mixture of disk drive, mass-storage, blazingly fast Internet access (via IEC port and/or user port), and hardware/software hackery for a completely new type of device for Commodore computers (or other retro computer).

Unleash Creativity.

The Comet+ has a built-in microcontroller, based on the Arduino development system. The Arduino bootloader was re-built to allow the Commodore 64 (or other computer) to upload Arduino "sketches" without the need for a PC to update it. This opens the doors for creating new types of peripherals and/or firmware. Users can create sketches to perform additional tasks not present in the default firmware or create new uses for some or all of the on-board components. Some examples might be:

  • Print to printers over the Internet or local LAN
  • Create your own on-board BBS system, utilizing the different components for communication or file access (files on the Internet or locally on the SD card and/or IEC port)
  • Parallel data transfers on the user port
  • SPI on the user port
  • Game Server (for example, use it for multiplayer games on
  • Web server
  • Extra processing power for your Commodore (use as a co-processor)
  • Internet-enable your 1541 disk drive (hook up a Comet+ to a 1541 drive and allow others to access it directly from their own Commodore computer across the Internet)
  • Compiler - Use the Arduino to compile BASIC programs or other high-level language to ML
  • Send a BASIC or ML program to the Arduino, which will then convert it to an Arduino Sketch.
  • LAN/Wi-fi bridge (provide wi-fi to a wired device)
  • Make a MIDI device
  • Make firmware that adds a Web Server Interface (as a server or maybe so you could configure your Comet+ options from a Web browser)