+++ATH0 That one normally only worked reliably if you could figure out some way of introducing a short delay between the +++ and the ATH. There may have been s

+++ATH0 That one normally only worked reliably if you could figure out some way of introducing a short delay between the +++ and the ATH. There may have been some crap modems that didn't require the delay, but that wasn't the spec. (the 0 was not necessary, btw, as 0 is the default for the ATH command)