When you are keying in a program PIPPIN will grumble at you if:-
* You have not entered any numbers (red keys) after an instruction other than and you try to enter another instruction.
* The memory is full. You can only enter 100 separate commands in one program.
* You have pressed when the memory is already empty.
* You have pressed 0 after a command that needs a number.
* You have pressed a number before entering a command.
* You have tried to enter too many numbers after a command. You can enter up to three numbers after all the commands except which needs just one number and which needs no number.
* You have tried to nest 's more than three deep.
* You have tried to put in an without a matching .
* You have left PIPPIN on for more than three minutes without pressing any buttons.
When you press or , PIPPIN will grumble at you if:-
* You have entered a command without an amount.
* You have entered a without a matching .
* PIPPIN has been stopped from running by running into something.
* You pressed a key to stop PIPPIN.
* If PIPPIN's battery is flat.
PIPPIN will sing when:-
* You turn PIPPIN on.
* Your program has run without any mistakes in it.