Question

Using a vending machine requires instructions from the person buying an item and the machine dispensing the item. Using terms and concepts learned this week, discuss the following activities.

What actions by either the person buying an item or the vending machine would you describe as a privilege or non-privileged instructions? Why?

Relate memory management concepts (virtual, real) to the operation of the vending machine. Relate processes and threads to the operation of the vending machine.

Directly address each question in your post. Your initial (first) post must be at least 150 - 200 words long.

Answer 1

In the operating system, there are two modes and these are used to separate the user mode from system mode to ensure protection and security of the system from unauthorized users. Any attempt to execute privilege instruction in user mode is not executed and treated as illegal privilege instructions. it is the responsibility of the system to ensure that the timer is set to interrupt
direct memory access is useful when a peripheral device and main memory need to transfer data between them and CPU instruction is not required .vending machine requires various instructions from buying an item and machine dispensing the item so various terms and concepts related to these instructions are described here.
setting the value of the timer is a privileged function and the timer is used for controlling the schedules if the user program runs until the timer goes off. If the user could set the value of the timer then it could have hogged the CPU.
Reading the clock is not a privileged instruction as reading the clock doesn't interfere with the kernel or other user programs.
Clearing the memory is a privileged instruction, and then checks that the process of wanting to clear memory can control the piece of memory.
Turning off the interrupt is a privilege condition as the OS should be in charge of setting the flow of control between kernel and user processes.
Switching from user to monitor mode is a privilege condition in which a user program can switch to a monitor mode where they could do whatever they want and it yields control to the kernel by making a system call.

A secure operating system that is running on architecture such that of a vending machine does not supply a privileged mode might operate by providing a virtual machine interface to a user program so that it checks each in instructions while it is running the OS must check each instruction and does one of the three things run it as is , run it with some modification or reject it.
Privileges instructions are used to prevent the user from running machine instruction they should not run