SD2IEC is a C64 SD card adapter and floppy disk drive emulator based on the design by Lars Pontoppidan with cassette port plug. Copy C64 games and programs to SD card on your PC, put the SD card in your SD2IEC and load games and programs on your C64!

The SD2IEC is a mass storage device using an SD/MMC card and interfacing with the IEC bus. It is based on the ATmega644P microcontroller. The most prominent use of SD2IEC is replacement of a Commodore 1541 disk drive for a C64, C128, C16 or VIC-20. It supports reading and writing the following file types: D64, D71, D81, PRG and P00 and works with many fast loaders, including EPYX Fastload. However, SD2IEC is not a complete disk drive emulator. Not every game will work from SD2IEC!

An AVR programmer is required to flash the firmware for the first time. A cheap and reliable programmer is e.g. USBasp. The SD2IEC must not be connected to the C64 during flashing!

• Remove the SD card.
• Connect the programmer to the PC via USB and to the ICSP header on the board via an ICSP cable.
• Make sure you have installed avrdude.
• Open a terminal.
• Navigate to the software folder with the hex-file.
• Execute the following commands one after the other (if necessary replace "usbasp" with the programmer you use):

  avrdude -c usbasp -p m644p -U flash:w:sd2iec-1.0.0-larsp-m644p.bin:a
  avrdude -c usbasp -p m644p -U hfuse:w:0x91:m -U lfuse:w:0xef:m -U efuse:w:0xfd:m
  

Firmware updates can be downloaded from https://www.sd2iec.de/nightlies/ (use firmware ...larsp-m644p.bin). Copy the BIN file to the root of the SD card. It is automatically flashed the next time the device is started up.

• Format an SD card (max 32GB, 1GB or 2GB cards work best) to FAT32 file system on your PC.
• Copy files from /software/sdcard_root to the root of the SD card.
• Download and copy C64 programs/games to root or organize them in folders.
• Put the SD card to SD2IEC.
• Plug the SD2IEC floppy emulator to the cassette port of your C64.
• Connect the IEC cable to the serial port of your C64.
• Turn on your C64.
• Type: LOAD "FB64",8 RETURN
• After the program loaded type: RUN RETURN
• This should load and run filebrowser. To navigate the menu either use cursor keys or Joystick in port2. For single D64 images, just open the D64 by pressing RETURN or FIRE and then select the first PRG file to LOAD.

You can change the address of your SD2IEC with the DIP switches:

1. Original Project
2. Firmware Download
3. Inofficial Manual
4. Another Manual
5. And another one
6. C64 Games
7. C64 Demos