Caps Shift doesn't work on ZX Spectrum

[Colourclash]

On the ZX Spectrum pressing Caps Shift does not do anything. In 48k BASIC pressing CAPS SHIFT should toggle between the 'L' and 'C' flashing cursor.

Try typing some letters and they will be in lower case when the cursor is a flashing 'L'. Pressing CAPS SHIFT should make the cursor turn into 'C' and cause upper case letters to be produced when alphabetical keys are pressed.

I fixed this issue by adding the following line in zx.h in _zx_init_keyboard_matrix():

kbd_register_key(&sys->kbd, 0x0E, 0, 0, 0); /* CapsShift */