 These "smart terminals" were a hit due both to their capabilities and to their ability to be run over inexpensive serial links, rather than custom connection as in the case of systems like the IBM 3270, which generally required expensive controllers for distributed applications.The VT100 was introduced in August 1978, replacing the VT50/VT52 family.Like the earlier models, it communicated with its host system over serial lines at a minimum speed of 50 bit/s, but increased the maximum speed to 19,200 bit/s, double that of the VT52.