In order to protect the operating systems and the system programs from the malfunctioning programs the two mode operations were evolved
42. What is a device queue?
A list of processes waiting for a particular I/O device is called device queue.
43. What are the different types of Real-Time Scheduling?
Hard real-time systems required to complete a critical task within a guaranteed amount of time.
Soft real-time computing requires that critical processes receive priority over less fortunate ones.
44. What is relative path and absolute path?
Absolute path– Exact path from root directory.
Relative path– Relative to the current path.
45. What are the disadvantages of context switching?
Time taken for switching from one process to other is pure over head. Because the system does no useful work while switching. So one of the solutions is to go for threading when ever possible.
46. What is a data register and address register?
Data registers – can be assigned to a variety of functions by the programmer. They can be used with any machine instruction that performs operations on data.
Address registers – contain main memory addresses of data and instructions or they contain a portion of the address that is used in the calculation of the complete addresses.
47. What is DRAM?
Dynamic Ram stores the data in the form of Capacitance, and Static RAM stores the data in Voltages.
48. What are local and global page replacements?
Local replacement means that an incoming page is brought in only to the relevant process’ address space. Global replacement policy allows any page frame from any process to be replaced. The latter is applicable to variable partitions model only.
49. Explain the concept of the batched operating systems?
In batched operating system the users gives their jobs to the operator who sorts the programs according to their requirements and executes them. This is time consuming but makes the CPU busy all the time.
50. What is SCSI?
SCSI – Small computer systems interface is a type of interface used for computer components such as hard drives, optical drives, scanners and tape drives. It is a competing technology to standard IDE (Integrated Drive Electronics).