(U.S. Robotics, Inc., Schaumburg, IL, www.usr.com) An earlier analog modem manufacturer highly regarded for its quality products. U.S. Robotics (USR) was an innovative company that manufactured its own chipsets (data pumps), and its Sportster models were the best-selling modems in the world. USR's HST protocol was a high-speed, reliable protocol before V.32bis became a modem standard in 1991.In 1997, USR became part of 3Com in the largest merger in data networking history. In 2000, it was spun off as a private, independent company formed by 3Com, Accton Technology Corporation and NatSteel Electronics, Ltd. In 2013, UNICOM Global acquired the company. See 3Com and analog modem.