Lab 4: PS/2 mouse packets

Generated folder: labs/mouse/

Lab 4 extends the i8042 controller idea to the auxiliary PS/2 mouse. The mouse reports packets containing button state, movement deltas, sign bits, and overflow flags.

The change from Lab 3 is that one device event is now a group of bytes. If you lose synchronization, every following byte can be misread until the parser finds the start of a packet. That makes the mouse a compact but serious protocol exercise.

Read why pointing devices changed interfaces, then the mouse controller path and packet parsing rules. Complete the tasks, validate with the checks, and compare with modern pointer input.

TIP

Mouse input is the first lab where losing one byte can corrupt every following interpretation until you resynchronize.