I still have full scans of local exchanges done with ToneLoc. The US Courier HST Dual Standard would detect "voice" and hang up which would boost it to around 2

I still have full scans of local exchanges done with ToneLoc. The US Courier HST Dual Standard would detect "voice" and hang up which would boost it to around 240 numbers per hour. Ah the good old days. Oh, and for a while there was soundblaster support that said, "Yo we found a carrier" whenever it hit a modem. Good times.