Lecture 5. Memory accesses and memory management. Swapping. Main components of an operating system

1. Memory accesses and memory management. Swapping.

Rakhmetulayeva Sabina
Senior lecture, PhD

2. Main Components Of An Operating System

Process Management
Disk And File Systems
Memory Management
Inter-process communication
(IPC)

3.

In the early days of electronic computing, two
different processor/memory architectures emerged:

4. Princeton Architecture   (von Neumann architecture)

5. The principles of von Neumann."

The principles of von Neumann."
1. The principle of program
control.
2. The principle of one memory.
3. The principle of memory
addressability.

6. Harvard Architecture – Two separate memories. One contains only data while the other is containing only program code.

7. Which is better?

Each
architecture
has
its
advantages: All else being equal,
the Harvard model has the edge in
performance. The Von Neumann
model is more flexible.

8. Types of memory

Automatic
static RAM
dynamic RAM

9. MCB

The concept of a memory control block (MCB) was
introduced in MS-DOS, Version 2.0, as the operating
system's basic method of tracking memory allocation for
application programs and installable device drivers.

10.

11.

Memory Technology Trade-offs

12.

Flat memory model or linear memory model

13.

14.

15. ADDRESS

Logical address is the address at which an item (memory cell,
storage element, network host) appears to reside from the
perspective of an executing application program. (selector, offset)
Linear address (also known as virtual address): are calculated
from virtual addresses by segment translation.
In computing, a physical address (also real address, or binary
address), is the end result of all the transformations of other types of
addresses