I am playing with an ATtiny13 and I thought it would be good to use it with an external 8Mhz ceramic oscillator instead of the 1.2 Mhz built-in one. (I want to do a soft-uart at 9600 bps, so I figured 1.2 Mhz was too slow)
To change to an external oscillator, I ran 'avrdude -c usbtiny -p attiny13 -U lfuse:w:0x70:m -U hfuse:w:0xff:m'
Unfortunately I can't access the device anymore now. The 'Blink the LED on PB0' program that was in there does not run anymore and the programmer can't connect to it.
Not sure what to do here. Can I throw away this chip or is there a way to rescue it?
Have you tried to set the chip up with an external oscillator? Once the chip is programmed to use an external oscillator it will not work unless one is present. If you do not do this you will need hi voltage programming to reset the fuses.