The arduino used in that solution is not running at 12V. Only the ATtiny RST is jolted at 12v. The resistors are there, I presume, to protect the arduino from high voltage signals.
Note that serial high-voltage programming is not appropriate for all ATtiny processors. For some, you use
parallel high-voltage programming instead.
http://support.atmel.no/knowledgebase/a ... mming.htmlThe Atmel STK500 supports high-voltage serial programming through avrdude. Special timing is required for this process (see page 159 of the
ATtiny45 datasheet for an example). If you hooked up the usbTiny correctly,I don't know whether or not it's avrdude profile would support the proper sequences.
I think your best bet would be to use an arduino, as in the solution you linked to, or simply get an Atmel STK500.