Silent 700
The Silent 700 was a line of portable computer terminals manufactured by Texas Instruments in the 1970s and 1980s. Silent 700s printed with a dot-matrix heating element onto a roll of heat-sensitive paper. Some models were equipped with an integrated acoustic coupler and modem that could receive data at 30 characters per second. Other models could be directly connected to computers at 300 baud, and were sometimes used as the System console where a hard copy record of the activities would be retained for a period of time.
As 1200-baud dialup communication became more common among Time-sharing providers, the Silent 700 faced the problem that its printhead technology simply couldn't "heat up all the little dots" at 120 characters per second. TI solved this in their 780-series terminals by creating a two-character-wide thermal head, which printed 60 pairs of characters per second. This allowed the product line to survive a few more years in the new high-speed interactive computing environment of the mid-1980s.