Next steps: Add absolute positioning (tablet mode), dynamic rate switching, or hook the driver into a windowing system. Happy coding! Did this article help you? Share your PS/2 driver war stories in the comments below.
int old_buttons = 0; while (1) Enabling Scroll Wheel (IntelliMouse) Send this sequence to switch to 4-byte packets: ps/2 compatible mouse driver
The PS/2 mouse might seem like a relic of the 1990s, but it remains the gold standard for low-level OS development. Unlike USB, which relies on complex host controllers and descriptor parsing, the PS/2 interface is simple, memory-mapped, and interrupt-driven. In this article, we’ll build a bare-bones PS/2 mouse driver from scratch, covering initialization, packet decoding, and integration with a simple GUI. 1. Understanding the PS/2 Interface The PS/2 port uses two bidirectional lines: Clock (usually IRQ 12 for the mouse) and Data . Communication is synchronous, with the device sending 11-bit packets (1 start bit, 8 data bits, 1 parity bit, 1 stop bit) when the host pulls the clock low. Next steps: Add absolute positioning (tablet mode), dynamic