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COS3721 Exam Questions And Answers
100% Verified And Updated.
1. The ____ register of an I/O port can be written by the host to start a command or to change the
mode of a device.
A) status
B) control
C) data-in
D) transfer - Answer✔B
2. An interrupt priority scheme can be used to ____.
A) allow the most urgent work to be finished first
B) make it possible for high-priority interrupts to preempt the execution of a low priority
interrupt
C) defer the handling of low-priority interrupt without masking off all interrupts
D) All of the above - Answer✔D
3. DMA controllers ____.
A) do not utilize an additional, special purpose, processor
B) are a nonstandard component in PCs of today
C) can steal memory access cycles from the main CPU
D) can access main memory at the same time as the main CPU - Answer✔C
4. A character-stream device ____.
A) transfers data in blocks of bytes
B) transfers data a byte at a time
C) is a device such as a disk drive
D) is similar to a random access device - Answer✔B
5. ____ I/O accesses a block device as a simple array of blocks.
A) Raw
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B) Stream
C) Indirect
D) Cooked - Answer✔A
6. Which of the following is true of a blocking system call?
A) The application continues to execute its code when the call is issued.
B) The call returns immediately without waiting for the I/O to complete.
C) The execution of the application is suspended when the call is issued.
D) Blocking application code is harder to understand than nonblocking application code -
Answer✔C
7. A(n) ____ is a buffer that holds output for a device that cannot accept interleaved data
streams.
A) escape B) block device
C) cache D) spool - Answer✔D
8. A sense key reports on the failure of a SCSI device by ____.
A) stating the general category of failure
B) stating the general nature of the failure
C) giving detailed information about the exact cause of failure
D) maintaining internal pages of error-log information - Answer✔B
9. A(n) ____ is a front-end processor that multiplexes the traffic from hundreds of remote
terminals into one port on a large
computer.
A) terminal concentrator
B) network daemon
C) I/O channel
D) context switch coordinator - Answer✔A
10. Which of the following is a principle that can improve the efficiency of I/O?
A) Increase the number of context switches.
B) Use small data transfers
C) Move processing primitives into hardware
D) Decrease concurrency using DMA controllers - Answer✔C
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COS3721 Exam Questions And Answers
100% Verified And Updated.
1. The ____ register of an I/O port can be written by the host to start a command or to change the
mode of a device.
A) status
B) control
C) data-in
D) transfer - Answer✔B
2. An interrupt priority scheme can be used to ____.
A) allow the most urgent work to be finished first
B) make it possible for high-priority interrupts to preempt the execution of a low priority
interrupt
C) defer the handling of low-priority interrupt without masking off all interrupts
D) All of the above - Answer✔D
3. DMA controllers ____.
A) do not utilize an additional, special purpose, processor
B) are a nonstandard component in PCs of today
C) can steal memory access cycles from the main CPU
D) can access main memory at the same time as the main CPU - Answer✔C
4. A character-stream device ____.
A) transfers data in blocks of bytes
B) transfers data a byte at a time
C) is a device such as a disk drive
D) is similar to a random access device - Answer✔B
5. ____ I/O accesses a block device as a simple array of blocks.
A) Raw
1|Page
, ©FYNDLAY 2024/2025 ALL RIGHTS RESERVED.
B) Stream
C) Indirect
D) Cooked - Answer✔A
6. Which of the following is true of a blocking system call?
A) The application continues to execute its code when the call is issued.
B) The call returns immediately without waiting for the I/O to complete.
C) The execution of the application is suspended when the call is issued.
D) Blocking application code is harder to understand than nonblocking application code -
Answer✔C
7. A(n) ____ is a buffer that holds output for a device that cannot accept interleaved data
streams.
A) escape B) block device
C) cache D) spool - Answer✔D
8. A sense key reports on the failure of a SCSI device by ____.
A) stating the general category of failure
B) stating the general nature of the failure
C) giving detailed information about the exact cause of failure
D) maintaining internal pages of error-log information - Answer✔B
9. A(n) ____ is a front-end processor that multiplexes the traffic from hundreds of remote
terminals into one port on a large
computer.
A) terminal concentrator
B) network daemon
C) I/O channel
D) context switch coordinator - Answer✔A
10. Which of the following is a principle that can improve the efficiency of I/O?
A) Increase the number of context switches.
B) Use small data transfers
C) Move processing primitives into hardware
D) Decrease concurrency using DMA controllers - Answer✔C
2|Page
