💻 VOS - VIRTUAL OPERATING SYSTEM SIMULATOR

VOS SIMULATOR - INSTRUCTIONS

After Execution -> Hover over memory cells to see their purpose and details.

Try job with errors to see error handling in action!

System Assumptions:

• Simulates basic OS operations including memory management and paging
• Supports time limits, line limits, and error handling
• Uses paging with page tables stored in real memory
• 30 memory blocks available for program allocation
• Handles program errors via Program Interrupt (PI)
• Handles time-out errors via Timer Interrupt (TI)

Supported Instructions:

• GD - Get Data (read input)
• PD - Put Data (write output)
• LR - Load Register
• SR - Store Register
• CR - Compare Register
• BT - Branch if True
• H - Halt

Error Codes:

• 0 - No Error
• 1 - Out Of Data
• 2 - Line Limit Exceeded
• 3 - Time Limit Exceeded
• 4 - Operation Code Error
• 5 - Operand Error
• 6 - Invalid Page Fault
• 7 - Instruction Limit Exceeded

Job Card Format

In one job only 10 instructions allowed

Each job card consists of the following sections:

• $AMJ: Indicates the start of a new job. Followed by:
  • Job ID: A unique identifier for the job (4 digits)
  • Time Limit: Maximum time allowed for execution (2 digits)
  • Line Limit: Maximum number of output lines allowed (2 digits)
• Program Instructions: A series of instructions to be executed by the OS. Each instruction is 4 characters long.
• $DTA: Indicates the start of the data section for the job.
• Input Data: Data to be read by GD instructions. Each line can contain up to 40 characters.
• $END: Indicates the end of the job card.