Works great, price / performance is good

I have the ISP now in use for two months and it works just fine. On Windows with AVR Studio no problems under Mac OS X with avrdude takes the flash always: there lays a avrdude a commemorative break of three or four seconds. Since the flash with AVR Studio ruckzuck goes is probably to avrdude. Except for this little break programming goes but wonderful. Can the necessary Adjustment (3.3V vs. 5V power supply via USB or from the target board, ...) on the jumper. Have the programmer previously used with some ATtinys and am satisfied.