#serial port

Modern computers, especially slim notebooks have far fewer ports compared to their predecessors from the last couple of decades. However, things weren't always this way, as computers used to have a multitude of ports that were often served single purposes. Keep scrolling if this means nothing to you.  PS/2 Long before Bluetooth and USB, keyboards and mice were connected to a computer using a PS/2 port. It's a circular port containing six pins and was introduced in 1987 as an innovation of the IBM Personal System/2, which is also where it gets its name from. Computers came with two PS/2 ports, one each for the keyboard and mouse, and were color coded -- purple for the keyboard, and green for the mouse. Nowadays though, if you do happen to have modern hardware with a PS/2 port, it's usually a single port that can support either a keyboard or mouse. Parallel/LPT Back then, printers too had their own dedicated port called "LPT" (line printer terminal) or more commonly, "Parellel" port. While other peripherals also used a parallel port, printers were perhaps the most common device to hook it up to. Read more in our articles including "Do you still remember these PC Ports?" and "Blogger-Friendly Airports".