pulse/tone
I didn't have cellular phone on that days. So, I decided to buy the device to connect to TTY-network, to stop wasting the time at work waiting only 3-4people to visit per a day....
My rich friend bought "Inline coupler". But I didn't have sufficient money to buy it. "OK, I'll call the phone directly , if I can't call through modem"....
Then, I got to the answer to use "coupler", the ancient network technology.
I wonder when I heard that "the maximum speed of coupler is 9600bps"....TELECOUPLER can connect to the network at 14400bps in "1", at 28000bps in "2", and at last 33600bps in "3"....Evolution of technology, or POWER OF "OTAKU('Mania' in Japanese)" surprises me deeply.
Even if there came rare patients in the pharmacy, there were some noises. So I tried hard to connect at 28800bps once a couple of trial, being fixed the coupler to the hand set tight, shielded with a bath towel and put into the desk.
But when I tried to connect from Chichijima, the tropical island where is 1,000km far to the south from Tokyo, I was surprised to be able to connect more stably at 14400bps than to connect the modem directly to subscriber.