.copy "core.asm" .sect ".data" hold .word 0 .sect ".text" main stm #hold,AR3 ; Read to hold location READSER 1 ; Read one byte from serial port cmpm AR1,#1 ; Did we get a character? bc main,NTC ; if not, branch back to start stm #hold,AR3 ; Write from hold location WRITSER 1 ; ... one byte b main