Explain the function of the ALE and IO/M signals of the 8085 microprocessor.

ALE: ALE stands for, Address Latch Enable. It is the 30th pin of 8085 which is used to enable or disable the address bus... the address bus will be enabled during the 1st clock cycle as the ALE pin goes high i.e. logic '1' during the first half cycle.

During 2nd and 3rd clock cycles it goes low i.e. logic ‘0’ indicating the address & data bus (AD0-AD7) is for data hence it disables the address & data bus during the 2nd and 3rd clock cycles.

IO/M: It is a status signal. It is used to differentiate between memory locations and I/O operations. When this signal is low (IO/M = 0) it denotes the memory related operations. When this signal is high (10/M = 1) it denotes an I/O operation.