Don't know about state of the art, but in the early 80s, 300 bps was the economical choice, relatively speaking, for home users. 1200 bps were around but were a

Don't know about state of the art, but in the early 80s, 300 bps was the economical choice, relatively speaking, for home users. 1200 bps were around but were a good deal less affordable and in quite a bit of the country, less reliable due to the general state of signal quality on the phone network at the time.