PA0465 Console Scientific Calculator Program

                                                               
  Operands can be entered using the touchpad in much the same  
  way that a calculator keypad is used. There are a couple of  
  keys that perhaps deserve special mention. The '<---' key    
  deletes the last digit that was entered in the operand field.
  The 'CLR' key clears the entire operand field if pressed once
  and clears the entire calculation if pressed twice in        
  succession.                                                  
  The 'E' key is used if you wish to enter an operand in       
  scientific notation. The 'EE' key latches and indicates that 
  future calculation results should be expressed in scientific 
  notation.                                                    
  The 'ENTER #1', etc. keys allow you to send an operand to    
  a particular operand field on the TV's calculation line.     
  The 'ENTER OPERAND' and 'ENTER OPERATR' keys allow you to    
  enter both operands and operators sequentially.