== Timings ==
The Atari/Amiga mice do output low-level signals, directly coming from the motion sensors. Ideally, software should check the signals ''more than 500 times per second''. FutureOS does that, but not the firmware. Using the CPCs 300Hz interrupt to check the signals might be a bit slow; it would work, but may miss some signals when the mouse is moved too fast.
Reading the mouse more often than 300 times per second would be better, but it'd require more CPU load since it can't be done via interrupts. Possibly best solution would be combination of IRQ and non-IRQ handling: Always check the mouse on 300Hz interrupts, and - if the program isn't busy with other tasks - additionally check it via polling.