IAS

Question 1

What is the purpose of the Control Counter register in the LAS machine?

Answer 1

It serves as the Program Counter (PC) and is 12 bits in size.

Question 2

What does the Memory Address Register (MAR) do in the LAS machine?

Answer 2

It holds the memory address and is 12 bits in size.

Question 3

How many bits is the Selectron Register (MBR) in the LAS machine?

Answer 3

It is 40 bits in size.

Question 4

What is the function of the Accumulator (AC) in the LAS machine?

Answer 4

It is used for arithmetic operations and is 40 bits in size.

Question 5

What is the size of the Arithmetic Register (MQ) in the LAS machine?

Answer 5

It is 40 bits in size.

Question 6

What does the Control Register (IBR) do in the LAS machine?

Answer 6

It holds control information and is 20 bits in size.

Question 7

What is the size of the Function Table Register (IR) in the LAS machine?

Answer 7

It is 8 bits in size.

Question 8

Fill in the blank: The LAS machine has _______ registers.

Answer 8

7

Question 9

True or False: The Control Counter register is 40 bits in size.

Answer 9

False

Question 10

List the registers in the LAS machine.

Answer 10

• Control Counter - PC (12 bits)
• Memory Address Register - MAR (12 bits)
• Selectron Register - MBR (40 bits)
• Accumulator - AC (40 bits)
• Arithmetic Register - MQ (40 bits)
• Control Register - IBR (20 bits)
• Function Table Register - IR (8 bits)

Question 12

What does S(x) -> Ac+ do?

Answer 12

Copy the number in Selectron location x into AC

AC stands for Accumulator

Question 13

What is the function of S(«) -> Ac-?

Answer 13

Copy the negative of the number in Selectron location x into AC

Question 14

What does S(x) -> AcM accomplish?

Answer 14

Copy the absolute value of the number in Selectron location x into AC

Question 15

What action is performed by S(x) -> Ac-M?

Answer 15

Copy the negative of the absolute value of the number in Selectron location x into AC

Question 16

What operation is performed by S(x) -> Ah+?

Answer 16

Add number in Selectron location x into the accumulator

Question 17

What does S(x) -> Ah- do?

Answer 17

Subtract number in Selectron location x from the accumulator

Question 19

What does S(x)->AhM represent?

Answer 19

Instruction to add absolute value of number in Selectron location x into the accumulator

Question 20

What does S(x)->Ah-M represent?

Answer 20

Instruction to subtract absolute value of number in Selectron location x from the accumulator

Question 21

What does S(x)->R signify?

Answer 21

Instruction to copy number in Selectron location x into AR

Question 22

What does R->A indicate?

Answer 22

Instruction to copy number in AR to AC

Question 23

What is the outcome of S(x)*R->A?

Answer 23

Multiply number in Selectron location x by the number in AR, placing left half in AC and right half in AR

Question 24

What does A/S(x)->R denote?

Answer 24

Divide the number in AC by the number in Selectron location x, placing quotient in AR and remainder in AC

Question 25

What is the function of the instruction to continue execution at the left-hand instruction of the pair at Selectron location x?

Answer 25

Continue execution at the left-hand instruction of the pair at Selectron location x

Question 26

What does the instruction to continue execution at the right-hand instruction of the pair at Selectron location x do?

Answer 26

Continue execution at the right-hand instruction of the pair at Selectron location x