LOCAL VS GLOBAL ALLOCATION POLLICIES The main issue occurs how the memory should be allocated and

The Operating System manages the flow of data and tells the processor what component needs to be doing. It does this my relaying one piece of information at a time but done so fast it seems it is doing it all at the same time. It does this by giving the information to the processer in computer language, so it can understand.

makes it difficult for programs to interface. Quite frequently data is just lost and not retrievable.

i) Memory : cache server (holds recently acesed web pages in its RAM, for spedier aces

Medium-term: it removes the processes from the memory, then reinstates them later to continue running.

Irregular Access memory is inside the PC which store the information and work with capacity memory to make lessen less and influence space for essential things to like record and documents in light of the fact that for individual protection.

1.19)Ans.The interrupts are used to indicate events like change in events or if any error occurs or freeing of resources or I/o

b) The address and control buses are activated with a memory address position and read command.

What is a swap file? How does the computer use this file? What information might be found there?

a. The CPU tells the RAM which address holds the data that the CPU wants to

The advantages of interrupt driven I/O over programmed I/O is that in interrupt driven I/O the interrupt mechanisms free I/O devices quickly.

Virtual to physical address translation - Virtual address consists of a virtual page number, index and offset. To get the physical page number (frame), we first check TLB to see if the requested address is there. If the address is not there, we check the page table. If the requested address is in the page table, we get the physical page number. If the requested address is not in the page table, page fault occurs and the page is eventually loaded into memory and TLB and we get the physical page number.

What I found out is that after doing the lab is that there are three cycles that the CPU goes through in order for the program to be executed. I was able to come up with small programs for 2a and 3b that will execute according to the instructions given in the lab, which is shown below.

There are two types of control unit which are hardwired and micro program where hardwired are for fixed architecture and are typically RISC and cost more than micro program because of the time required to design the circuits , but they are faster. Micro program control units are slower than hardwired but are easier and cheaper to implement as the instructions are stored in special control memory. The control unit controls all data going in, out and inside the CPU. The control unit decodes the data from ram and turns it into an instruction depending on what instruction set the control unit is programed or hardwired to have. Then if the instruction involves any logic or mathamatical caluculations it gets sent to the alu

mm: memory modify (auto-incrementing) This command mm is used to modify the memory contents. It will display the current and address contents which are used as user input. If we enter a legal hexadecimal number, this new value will be written to the address. If we don't enter any value and just press ENTER, then the contents of this address will remain unchanged. The command stops as soon as the data entered is not a hex number as shown in the figure 12.

This would mean programmers would have to edit their code every time they changed machines or added more memory (Lemley, 1999). Early computers had small amounts of RAM because storage technology was very expensive. Programmers had to store master copies of programs on a secondary storage system and pull pieces into RAM as needed. The process of deciding which pieces to pull and which parts of RAM to replace was called “overlaying” (Denning, 2012). “It was estimated that most programmers spent half to two-thirds of their time planning overlay sequences. A reliable method of automating it had potential to increase programmer productivity and reduce debugging by several fold” (Denning, 2012). Thus, the concept of virtual memory was born. This concept makes use of the computer’s hard drive when main memory runs out. However, the hard drive is significantly slower than RAM so we want to keep most of the program functioning in RAM thus specialized hardware and software is needed to give the illusion of unlimited available fast memory (Lemley, 1999). This hardware converts a “virtual” address to a physical address in memory. Aside from virtually increasing memory size, virtual memory also provided three additional benefits, “it isolated users from each other, it allowed dynamic relocation of program pieces within RAM, and it provided read – write access control to individual pieces” (Denning, 2012). It is for these