Introduction 8085 is an 8-bit microprocessor an address a maximum of 216 = 65536 memory location. It has a total of 16-pin on the package which will be used to carry both the address as well as the data. The low order address lines are multiplexed with 8-data lines and hence the pin 11 to 19 on the 8085 microprocessor IC are numbered as AD7 - AD0 (pin 12-19), whereas the high order bus is marked as A15 - A8 (pin 21-28) as shown in following cut-section diagram. For accessing the memory full 16-bit address value must appear at once on pins A15 – A0 but the lower byte is not exclusively available to carry the address, it also carries the data. It