Operating System Simulator

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Simulation of Operating System fuctionality such as

1. Memory Managment
2. Virtual Memory
3. Process Execution
4. Process Scheduling
5. Interuppt Handling

Phase - 1

Problem Statement :

1. CPU / Machine Simulation
2. Supervisor Call through interrupt

Assumption :

1. Jobs entered without error in input file
2. No physical separation between jobs
3. Job outputs separated in output file by 2 blank lines
4. Program loaded in memory starting at location 00
5. No multiprogramming, load and run one program at a time
6. SI interrupts for service request

NOTATION

M: memory;
IR: Instruction Register (4 bytes)
IR [1, 2]: Bytes 1, 2 of IR/Operation Code
IR [3, 4]: Bytes 3,4 of IR/Operand Address
M [&]: Content of memory location
IC: Instruction Counter Register (2 bytes)
R: General Purpose Register (4 bytes)
C: Toggle (1 byte)

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Phase - 2

Problem Statement :

1. CPU / Machine Simulation
2. Supervisor Call through interrupt
3. Multiple-Program execution
4. Error handling in jobs
5. Handling Program interrupt,Timing interrupt and system interrupt

ASSUMPTIONS:

1. Jobs may have program errors
2. PI interrupt for program errors introduced
3. No physical separation between jobs
4. Job outputs separated in output file by 2 blank lines
5. Paging introduced, page table stored in real memory
6. Program pages allocated one of 30 memory block using random number generator
7. Load and run one program at a time
8. Time limit, line limit, out-of-data errors introduced
9. TI interrupt for time-out error introduced
10. 2-line messages printed at termination

NOTATION

M: memory
IR: Instruction Register (4 bytes)
IR [1,2]: Bytes 1,2 of IR/Operation Code
IR [3, 4]: Bytes 3, 4 of IR/Operand Address
M[&]: Content of memory location
IC: Instruction Counter Register (2 bytes)
R: General Purpose Register (4 bytes)
C: Toggle (1 byte)
PTR: Page Table Register (4 bytes)
PCB: Process Control Block (data structure)
VA: Virtual Address
RA: Real Address
TTC: Total Time Counter
LLC: Line Limit Counter
TTL: Total Time Limit
TLL: Total Line Limit
EM: Error Message