a) Give hardware block diagram for a 42 ROM. b) Give a hardware block diagram for a 42 RAM. c) Give hardware bloc diagram for an 84 memory module using 42 memory modules. d) Give hardware block diagram of a computer system composed of a processor, four I/O devices, an 84 memory module, and a common bus. Consider Memory Mapped I/O for interconnecting these units. Also identify memory and I/O address spaces