"[4] The 2770 was developed by the IBM General Products Division (GPD) in Rochester, MN.
It provides the ability to interleave data between devices, introduces double buffering, and adds support for the Wait-before-transmit ACKnowledgement (WACK) and Temporary Text Delay (TTD) Binary Synchronous control characters.
[10] The IBM 2780 and 3780 were later emulated on various types of equipment, including eventually the personal computer.
[12] In 1974 IBM Data Processing Division (DPD) offered a successor to the 3780, called the 3770 Data Communications System, supporting SDLC, BSC, BSC Multi-leaving[13] and SNA, depending on the configuration.
[14] The 3770 is a family of desk console style terminals that offers a variety of keyboard and printer combinations as well as I/O equipment attachment and communications features.