SoftwareSerial with ATTiny84 using ATtiny library

this is the output, though for some reason I always have to send "!" twice for it to work:

I've had that happen a few times but typically the transition is smooth. I can't explain why you always have to send bang twice.

ÿ //this shows up without me typing "!"

I often get a bit of garbage as well. I haven't bothered to track down why.