Originally Posted by rich smith
The 4mhz spec is for use with very low voltage (1.8v). At 5v the chip runs at 8mhz and higher so there is no problem. In fact I've run them at 20mhz with xtl.
ATtiny12L datasheet says 2.7 - 5.5V , 0-4 MHz, but ok thanks , i'll try.