extern int comma; /* The current comma setting : true if decimal point is a comma,
 false if it is a point */

enum KeyTypes ReadKey(WORD *); /* Read a complete key sequence */
void Disp(void); /* Display the current value of X register */
void Error(int); /* Display Error n */
int GetKey(void); /* Read a key from the HP11 (waiting for its release) */
int scrpos(char *, int); /* Return position n on the liquid cristal display in string t */
int scrlen(char *); /* Return the length taken up on the screen by the string */
void DisplayLine(void); /* Display current program line */
char *NbStr(double); /* Convert number into string according to current mode */