What are the hardware requirements of multiprogramming operating system?

Answer 1

SPECIAL REQUIRMENTS OF A MULTIPROGRAMMING OS:-

(A)I/O interrupts and DMA.

=>In order to execute instructions while I/O device is busy.

(B)MEMORY management.

=>Several ready-to-run jobs must be kept in memory.So we need more memory size.

(C)MEMORY protection.

=>data and programs

A multiprogramming system requires:

• A CPU (central processing unit) supporting a user mode for application processes and a system mode which can execute privileged instructions that control devices, memory management and other parts of the hardware. It can be called system mode, privilege mode, supervisor mode or kernel mode and it is possible to have more than one of these to allow different levels of system control. Application programs requesting reads, writes and other privileged functions pass the request to the system which in system mode would verify the validity of the request, executes the request if possible or queues the request to be done later and selects a different process to run.
• DMA (direct memory access) hardware to allow fast data transfers independent of program execution.
• A Clock/timer with interrupt capability allowing system software to manage time allocation of application programs and to pause them to allow other programs to run.
• I/O device interrupt structure to interrupt running programs so that the system can process I/O device completion and other requests and then return control to the running program.
• Memory mapping hardware to give running processes there own memory address area.
• Memory protection to prevent a running program from violating the integrity of other applications already in memory and to determine when a running process is using a memory address that has been swapped out so it can be brought back in.