US Robotics Inc continued its storming run after hitting back at the end of the last fiscal. The Skokie, Illinois modem and networking hardware manufacturer yesterday turned in first quarter net profits up 66% to $69.0m, or $0.72 per share as revenues soared 77% to $645.4m. The per share figure was right on the button with Street estimates, according to First Call estimates. The main driving force was sales of PC-related products, the company reported, with sales of its desktop modems, PC card modems and Pilot organizer rising 80% year-on-year in the first quarter, with prices on average remaining at the level they were a year earlier. Though the company added that it experienced strong demand right across it’s modem and networking lines. US Robotics’ near-term success depends in part on acceptance of its x2 56Kbps technology. It would provide access speeds up to twice as fast as most home users are used to right now. So far several significant players, including Rockwell International and Lucent Technologies have endorsed the technology. Selling and marketing expenses increased 111% to represent 15.6% of revenues, due to x2 advertising and more staff, and helped to push overall operating expenses up to 25.6% of revenues. President and COO John McCartney said he expected to demand for its entire existing product line to continue grow through the rest of fiscal 1997, with x2 something of an unknown quantity.