IAS Flashcards
What is the purpose of the Control Counter register in the LAS machine?
It serves as the Program Counter (PC) and is 12 bits in size.
What does the Memory Address Register (MAR) do in the LAS machine?
It holds the memory address and is 12 bits in size.
How many bits is the Selectron Register (MBR) in the LAS machine?
It is 40 bits in size.
What is the function of the Accumulator (AC) in the LAS machine?
It is used for arithmetic operations and is 40 bits in size.
What is the size of the Arithmetic Register (MQ) in the LAS machine?
It is 40 bits in size.
What does the Control Register (IBR) do in the LAS machine?
It holds control information and is 20 bits in size.
What is the size of the Function Table Register (IR) in the LAS machine?
It is 8 bits in size.
Fill in the blank: The LAS machine has _______ registers.
7
True or False: The Control Counter register is 40 bits in size.
False
List the registers in the LAS machine.
- 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)
What does S(x) -> Ac+ do?
Copy the number in Selectron location x into AC
AC stands for Accumulator
What is the function of S(«) -> Ac-?
Copy the negative of the number in Selectron location x into AC
What does S(x) -> AcM accomplish?
Copy the absolute value of the number in Selectron location x into AC
What action is performed by S(x) -> Ac-M?
Copy the negative of the absolute value of the number in Selectron location x into AC
What operation is performed by S(x) -> Ah+?
Add number in Selectron location x into the accumulator
What does S(x) -> Ah- do?
Subtract number in Selectron location x from the accumulator
What does S(x)->AhM represent?
Instruction to add absolute value of number in Selectron location x into the accumulator
What does S(x)->Ah-M represent?
Instruction to subtract absolute value of number in Selectron location x from the accumulator
What does S(x)->R signify?
Instruction to copy number in Selectron location x into AR
What does R->A indicate?
Instruction to copy number in AR to AC
What is the outcome of S(x)*R->A?
Multiply number in Selectron location x by the number in AR, placing left half in AC and right half in AR
What does A/S(x)->R denote?
Divide the number in AC by the number in Selectron location x, placing quotient in AR and remainder in AC
What is the function of the instruction to continue execution at the left-hand instruction of the pair at Selectron location x?
Continue execution at the left-hand instruction of the pair at Selectron location x
What does the instruction to continue execution at the right-hand instruction of the pair at Selectron location x do?
Continue execution at the right-hand instruction of the pair at Selectron location x
