     4. Automatic calculation
This mode is more useful if the  user  wishes  to  create  a  mini  table  of 
results. (The original BS tables are obviously better  if  more  than  a  few 
values are required.) PRT Calc prompts for a starting value, an end value and
a step size. It then performs the required calculations automatically. It  is 
advisable to enable the printer option before using this mode.
     5. Change direction
This is one of the option  items,  with  just  two  options;  temperature  to 
resistance or vice verse. The default is temp > res. in which case  the  user 
inputs a temperature and  PRT Calc  calculates  the  corresponding resistance
Either of the horizontal curser keys, or the RETURN key, just toggle  between 
the two options.
     6. Printer output
This is another  two  option  item;  enabled  or  disabled.  The  default  is 
disabled, in which case the results are displayed on the screen only. If this 
option is enabled then results are also output to a printer (assuming one  is 
connected of course).
                                                                     (Cont...
