LCR stands for Load Compliment Register. The use of this instruction results in loading of the value in two's complement format from the second operand register into the first. Basically, the value (number) loaded is the opposite sign of what was in the second operand register. That is, a negative 3, for example. will be made positive when loaded into the first operand register; and again for example, a positive 3, will become negative 3 when loaded into the first operand register.