Exchange the contents of the low byte of register X with register A.
Program that allows you to calculate the address of an element located in a two-dimensional array of dimension 3x3. The array is located at $8100. The index is specified by registers A and B, where A is the row number, B is the array column number.
Program that copies the contents of registers A and B to register X in such a way that the high tetrad of register A and the high tetrad of register B constitute the high byte of the X register, and the low tetrads constitute the low byte.
Sort in descending order of numbers located in cells $8200 ... $82ff.