SD2IEC is a hardware mass storage device using an SD/MMC card and interfacing with the IEC bus. It is based on the ATmega644 microcontroller from the Atmel AVR microcontroller family. The most prominent use of SD2IEC is emulation/replacement of a Commodore-1541 disk drive for a C64.

Hardware and the microcontroller’s firmware is available as open source (GPL).

Changelog:

2009-03-08 – release 0.8.0

• Direct sector access of the real storage device
• Ignore DEL files in file_open
• Drive mapper
• EXOS V3 fastloader support
• Requires avr-libc 1.6.x

2009-03-07 – release 0.6.7

• Bugfix: Close previous file if secondary is reused without close
• Bugfix: Minor Jiffy timing fix on EOI

source: sd2iec.de gitweb forum thread

The annoying bug in the firmware that had rendered the Ethernet interface almost useless has finally been fixed.

In comparison to 1.5, the following has been fixed:

• Reads from the Ethernet chip have been fixed. The unit now correctly receives packets.

download: 1541U Homepage

SD2Iec – is a hardware mass storage device using an SD/MMC card and interfacing with the IEC bus.

Changelog:

2008-10-02 – release 0.8.0pre1

• Implement Dreamload emulation.
• RTC support.
• Dataflash support.
• Multi-file scratch.
• Copy command.
• Large buffer support.
• Final Cartridge 3 freezed file fastloader support.
• D71/D81 disk image support.
• Parse FSINFO sector for faster FAT32 free space calculation.
• Partial REL file support.

download: sd2iec.de

source: gitweb forum thread