int e l 7.1 SPECIAL FUNCTION OPERATORS XTAL The XTAL operator tells MCS BASIC-52 what frequency the system is operating at. The XTAL operator is used by MCS BASIC-52 to calculate thc REAL TIME CLOCK reload value, the PROM programming timing, and the software serial port baud rate generation. The XTAL value is expressed in Hz. So, XTAL = 9000000 would set the XTAL value to 9 MHz. - 93 -