It’s assumed that you have procured one USBasp Programmer from your trusted component vendor! Connecting the programmer to your computer comprises of two steps. First step is the physical connection ...

To program these chips, [Aaron] first had to wire up the microcontroller into a circuit. This was just a bit of perf board, a resistor, a few caps, and a USB A plug.

February 9, 2012 The V-USB library is a pretty handy piece of code that lets you add USB connectivity to ATtiny microcontrollers (it was previously named tinyUSB).