Version 1.0 of the Universal Serial Bus (USB) standard was released in January 1996. 25 years and three attempts later, we’ve gone from USB 1.0’s 12 Mbit/s speeds to USB4’s 40 Gbit/s speeds. Here’s how USB conquered the world. The Problem: Wrestling with Ports and IRQs In the early 1990s, connecting peripherals to PCs was a mess. To use set up any PC, you had to utilize a handful of different types of incompatible ports and connectors. Most commonly, those included a keyboard port, a 9- or 25-pin RS-232 serial port , and a 25-pin parallel port . In addition, PC game controllers used their own 15-pin standard, and mice often plugged into serial ports or proprietary cards. At the same time, peripheral manufacturers began bumping into data rate limits in existing ports used for peripherals on PCs. Demand for telephony, video, and audio applications was growing. Traditionally, vendors had sidestepped these limitations by introducing their own proprietary ports that could be … [Read more...] about 25 Years of Making Connections With USB (After Three Attempts)