1. How many bits are required to address a 8M X 32 main memory if

a) Main memory is byte addressable? ______

b) Main memory is word addressable? ______

2. Suppose that a 8M X 16 main memory is built using 1M X 8 RAM chips and memory is word addressable.

a) How many RAM chips are necessary? ______

b) How many RAM chips are needed for each memory word? _______

c) How many address bits are needed for each RAM chip? _______

d) How many address bits are needed for all memory? _______

3. A digital computer has a memory unit with 20 bits per word. The instruction set consists of 80 different operations. All instructions have an operation code part (opcode), and an address part (allowing for only one address). Each instruction is stored in one word of memory.

a) How many bits are needed for the opcode? ________

b) How many bits are left for the address part of the instruction? _______

c) What is the maximum allowable size (in words) for memory? _________

4. Write the following MARIE assembly language equivalent of the following machine language instructions

a) 0001 1010 1001 0111

b) 0110 0000 0000 0000

c) 1000 0100 0000 0000

d) 0100 0001 0010 0011

5. List the hexadecimal code for the following program.

Hex Address Label Instruction Hexadecimal Code

100 - - - - - - - - - - - - - - - - - Load A - - - - - - - - - - - - -

101 - - - - - - - - - - - - - - - - - Add ONE - - - - - - - - - - -

102 - - - - - - - - - - - - - - - - - Jump S1 - - - - - - - - - - -

103 - - - - - - - S2 ,- - - - - - - Add ONE - - - - - - - - - - -

104 - - - - - - - - - - - - - - - - - Store A - - - - - - - - - - - -

105 - - - - - - - - - - - - - - - - - Halt - - - - - - - - - - - - - - -

106 - - - - - - - S1 ,- - - - - - - Add A - - - - - - - - - - - - -

107 - - - - - - - - - - - - - - - - - Jump S2 - - - - - - - - - - -

108 - - - - - - - A ,- - - - - - - - HEX 0020 - - - - - - - - - -

109 - - - - - - - ONE,- - - - - - HEX 0001 - - - - - - - - - -