Batt4.5V (-)  ------------------ Pin8 GND            Pin8 GND
  Batt4.5V (+)  ------------------ Pin7 +5V            Pin7 +5V
 
The low-level XA/XB/YA/YB signal must be watched by software (the 300Hz interrupt is probably too slow to sense fast motions, so there's little chance to have the mouse driver running in background).
=== CPC Plus Compatibility ===