I/O Mapping MCQ Quiz - Objective Question with Answer for I/O Mapping - Download Free PDF

Concept:

• Scheduling of a process in operating systems is done to finish the work in time.
• Different timing description with respect to a process is as shown:

          Arrival time: Time at which the process arrives in the ready Queue.

          Completion/Execution Time: Time at which the process completes its execution.

          Burst Time: Time Required by a process for CPU execution

          Turn-Around Time: Time difference between completion time and arrival time.

          Turn around time = Completion Time – Arrival Time.

Calculation:

Given Wait time due to I/O = 0s

Completion / Execution Time of P₁ = 6ms

Completion / Execution Time of P₂ = 4ms

Completion / Execution Time of P₃ = 2ms

Waiting Time of Process P₁ = Execution time of P₁ + Execution time of P₂ + Execution time fo P₃ + Wait time due to I/O.

= 6ms + 4ms + 2ms + 0

= 12ms

Turn around time of process P₁ = Execution Time - Arrival time.

= 6 ms - 0

= 6ms

So, Option (1) is Correct.

• Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory (random-access memory), independent of the central processing unit (CPU).
• DMA avoids using the CPU thus allowing the CPU to attend another job
• It increases the speed of the data transfer between the memory and the I/O devices
• DMA is used when a large amount of data is to be printed out from the memory of a computer
• The problem of slow data transfer between input-output port and memory or between two memory is avoided by implementing the Direct Memory Access (DMA) technique
• It is implemented by using 8257 DMA controller

• Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory (random-access memory), independent of the central processing unit (CPU).
• DMA avoids using the CPU thus allowing the CPU to attend another job
• It increases the speed of the data transfer between the memory and the I/O devices
• DMA is used when a large amount of data is to be printed out from the memory of a computer
• The problem of slow data transfer between input-output port and memory or between two memory is avoided by implementing the Direct Memory Access (DMA) technique
• It is implemented by using 8257 DMA controller

Concept:

• Scheduling of a process in operating systems is done to finish the work in time.
• Different timing description with respect to a process is as shown:

          Arrival time: Time at which the process arrives in the ready Queue.

          Completion/Execution Time: Time at which the process completes its execution.

          Burst Time: Time Required by a process for CPU execution

          Turn-Around Time: Time difference between completion time and arrival time.

          Turn around time = Completion Time – Arrival Time.

Calculation:

Given Wait time due to I/O = 0s

Completion / Execution Time of P₁ = 6ms

Completion / Execution Time of P₂ = 4ms

Completion / Execution Time of P₃ = 2ms

Waiting Time of Process P₁ = Execution time of P₁ + Execution time of P₂ + Execution time fo P₃ + Wait time due to I/O.

= 6ms + 4ms + 2ms + 0

= 12ms

Turn around time of process P₁ = Execution Time - Arrival time.

= 6 ms - 0

= 6ms

So, Option (1) is Correct.