How does the speed work in VirtualWire Library I'm analyzing the VirtualWire library and in it, the send messages are being sent with digitalWrite in the "send" method. However, there is a setup speed function. I'm reading that function and I see a lot of prescalers and TCCR variables. However, I'm not quite sure what these things do. Because, if it uses digitalWrite anyway to send the bits, then really is no intrabit delay, etc. Can someone please clarify this?

Sorry if question is convoluted. Happy to do any clarification. Thank you for all guidance!

EDIT: Also, how do I transmit a block of message. Something greater than a byte? I'm trying to calculate BLER of messages and software serial only transmits 1 byte at a time. While virtualWire uses low-level error detection (and i want to avoid the use of any error detection/correction).
I think that is used for receiving. By setting the speed, it knows how often it needs to read the input pin. It does this using timer interrupts, so it will run "in the background" without interfering with the main (loop) code. 

The TCCR stuff is the set the interval for the timer interrupt.