While ringing a plain course, why do the tool-bar buttons for bobs and singles turn themselves off and on again at the end of every lead?
The buttons disable themselves during the brief period when it would be ambiguous to make a call. Like real ringers, the bells on the screen require a couple of blows’ notice to cope with calls. Once the deadline has been reached there is a period of ambiguity – the actual making of the bob or single (or no call) has still to be witnessed on the screen, but the program is a couple of blows ahead of the visible action and so the bells are committed to your decision. Once the processing of the bob or single (or lack thereof) has finished inside the program, the buttons are made available again. The sense behind doing this becomes more obvious when you try calling a touch of Original, where calls can occur at every handstroke. It is essential in this situation to have a clear dividing line between calling opportunities.
