The Amstrad Analogue Joystick AJ-5 is a 2-axis, 2 button, analogue joystick.
The axes are up and down, and the 2 buttons are digital. The joystick is self centering, e.g. the stick will return to centre position if released.
The joystick has a 15-pin male D-type connector and is suitable for connecting to the old PC gameports and to the 464+ and 6128+ analogue joystick connector. When used with Windows, in the "Game Controllers" control panel you should pick "2-axis, 2-button joystick" for the type. It is recognised and can be used under Windows XP.
On the top, next to the joystick are 2 sliding controls. These can be used to adjust the values read from the joystick. When testing in Windows, moving these sliders allowed me to modify the centre point before calibration. So these are some form of calibration adjusters where calibration in software is not done.
However, if these are put to the centre positions and correct calibration is done, then the joystick works as expected.