Probably this programmer cable can be found on every AVR fan website. It very simple and easy to build. You just need few passive components that can be packed inside LPT connector. From my perspective I wouldn’t recommend using this one programmer if you are more serious in microcontroller projects, because it has poor computer port protection. It connects directly to LPT port without precautions. I definitely recommend using similar ISP circuit with buffer IC between LPT and target board.
But let’s don’t pretend like we are very smart. The whole beauty is in its simplicity. This thing does its job perfectly as long as target board power supply is OK.
Note for those who are thinking what is this thing for… I answer – this is an in Circuit programmer adapter for AVR microcontrollers that can be used to program MCU’s without removing them form the board. This is especially important feature if you are using SMD parts where you cannot use any sockets to place your IC. [build one]