Will be one of:

• Wally data.
• Wilma data.
• Tom data.
• Dick data.
• Harry data.

Holds the control method.

Byte	Option
00	Keyboard
01	Kempston Joystick
02	Sinclair Joystick

This is 00 until a digit has been written. It's used to suppress writing leading 00's so the output is "£ 10" instead of "£010".

Initialised to 1E at BAAD and the countdown is made by Redraw_Banner_Underline.