The document discusses implementing paging algorithms FIFO and LRU in NachOS. The authors tried to implement the algorithms in NachOS but encountered errors when compiling. They then implemented the paging algorithms in Java files instead. The document also discusses page tables, which map virtual addresses to physical addresses and are used in virtual memory systems to identify which pages are in memory and their locations.

1. NACHOS 2
PRACTICAL PART
Carlos Eduardo Triana Sarmiento.
Jonathan Alvarado Mata.
Obed David Guevara Ibarra.

2. Paging Algorithms
We tried to implement in nachOS the paging algorithms FIFO
and LRU, but we have some errors when compiling.
To test our programs of paging algorithms we first made
userprograms, while we were doing these user programs we
had some errors so we implemented paging-swap programs
out of nachOS.
So that's why we wrote the paging algorithms in java
Here are the two programs (FIFO and LRU).

3. FIFO

4. FIFO second part

5. FIFO Result

6. LRU

7. LRU second part

8. LRU result

9. Page Table
A page table is the data structure used by a virtual memory
system in a computer operating system to store the
mapping between virtual addresses and physical
addresses.
Each address space within the system has associated with
it a page table and a disk map. Each of these two tables
describe an *entire* address space. The page table
identifies which pages are in main memory, and in which
page frames those pages are located. The disk map
identifies where all the pages are on the disk. The entire
address space is on the disk, but only a subset of it is
resident in main memory.

11. Page Table

12. Page Table result