CSC 2111: Computer Organisation and Architecture

What is the smallest unit of data in a computer?

Bit

How many bits are in a byte?

8

What is the purpose of the sign bit in a binary number?

To determine the sign of the number

How many storage locations are in the main memory of the IAS computer?

4,096 Signup and view all the answers

What is the normal unit of information in which data is stored, transmitted, or operated on within a computer?

Word Signup and view all the answers

What is the total number of bits in an instruction in the IAS computer?

20 Signup and view all the answers

What is the main advantage of the stored programme concept?

It enables alteration of the program without physical modification Signup and view all the answers

What type of technology is used in the IAS computer?

Vacuum tubes Signup and view all the answers

What is the function of the control unit in a von Neumann machine?

To interpret instructions and execute them Signup and view all the answers

What is the main difference between a von Neumann machine and earlier computers?

It uses a stored programme concept Signup and view all the answers

What is the ALU capable of operating on?

Binary data Signup and view all the answers

What is the function of the main memory in a von Neumann machine?

To store data and instructions Signup and view all the answers

What is the function of the Memory Address Register (MAR)?

Specifies the address in memory of the word to be written from or read into the MBR Signup and view all the answers

What is the purpose of the Instruction Buffer Register (IBR)?

To hold temporarily the right hand instruction from a word in memory Signup and view all the answers

What occurs in the Fetch sub-cycle of the instruction cycle?

The instruction is retrieved from memory and stored in the Instruction Register Signup and view all the answers

What is the purpose of the Accumulator (AC) and Multiplier Quotient (MQ)?

To hold temporarily operands and results of ALU operations Signup and view all the answers

What is the function of the Program Counter (PC)?

To contain the address of the next instruction pair to be fetched from memory Signup and view all the answers

What is the main function of the control unit in the IAS computer?

To interpret instructions and cause them to be executed Signup and view all the answers

What happens during the fetch cycle?

The opcode of the next instruction is loaded into the IR and the address portion is loaded into the MAR. Signup and view all the answers

What is the purpose of the control circuitry?

To interpret the opcode and execute the instruction. Signup and view all the answers

What type of instruction allows decision points in a program?

Conditional branch instruction. Signup and view all the answers

What is the result of an unconditional branch instruction?

The sequence of instructions is changed. Signup and view all the answers

What is the purpose of the address modify instruction?

To compute addresses in the ALU and insert them into instructions. Signup and view all the answers

What is the role of the ALU in the IAS computer?

To perform arithmetic operations and data transfer. Signup and view all the answers