[sweetlilmre] is just beginning his adventures in retrocomputing, and after realizing there were places besides eBay to buy old computers, quickly snagged a few of the Amigas he lusted after in his youth. One of the machines that didn’t make it into his collection until recently was a Commodore 64 with Datasette and 1541 drive. With no tapes and a 1541 disk drive that required significant restoration, he looked at other devices to load programs onto his C64.
These devices, clever cartridge implementations of SD cards and Flash memory, cost more than anyone should spend on a C64. Realizing there’s still a cassette port on the C64, [sweetlilmre] created Tapuino, the $20 Commodore tape emulator
The hardware used to load games through the Datasette connector included an Arduino Nano, a microSD breakout board, a 16×2 LCD, some resistors, buttons, and a little bit of wire. The firmware part of the build – available here on the Git - reads the .TAP files off the SD card and loads them into the C64.
[sweetlilmre] posted a very complete build post of the entire device constructed on a piece of protoboard, Pop that thing in a 3D printed case, and he can have the entire C64 library in his pocket.

http://hackaday.com/2014/07/25/the-e...n-your-pocket/