Outside a 76 station on West Charleston Boulevard on a recent Friday afternoon, John Syntax takes a drag off of a Parliament cigarette and waits … and waits ... for five $100 bills to emerge at the bitcoin ATM, or BTM, inside. He’s been here nearly an hour. A network that supposedly cranked up its processing speed in 2015, when it was seven transactions per second, still operates in the bike lane. Visa, by contrast, zips along at ...