A simple virtual machine implementation using a custom machine code. Very early alpha, but it works. It currently can calculate the Fibonacci sequence with a program written in the VM machine code.

This will eventually used as a part of a complete project.

Download the latest version or compile the application with Visual Studio 2010. To change the running program, one currently needs to edit the source.

• none (press enter)
  • Executes the next instruction
• printmem [location]
  • Displays the memory contents, either at the program counter or at an optional parameter
• printreg
  • Shows the contents of all registers
• quit
  • Ends the simulation

######Registers:

• General Purpose
  • A - 0
  • B - 1
  • C - 2
  • D - 3
  • E - 4
  • F - 5
• Program Counter
  • PC- 6

Memory Addressable from 0 to 8191 (2^13-1)

######Instruction Formats:

• Load/Store Format: 00 0000 0000 0000

  • Instruction Type
  • Register To Use
  • Memory/Register Address
  • Flags
    • 0000 - Load/Store data from register from/to memory address
    • 0001 - Load/Store data from register from/to register (memory address used as register number)

• Mathematics Format: 02 0000 0000 0000

  • Instruction Type
  • Register (that will be operated on, result of calculation)
  • Register (that will be copied from, unchanged)

• Jump Format: 07 0000 0000 0000

  • Instruction Type
  • Register To Use
  • Memory/Register Address
  • Flags
    • 0000 - Jump if register is zero
    • 0001 - Jump if register is less than zero
    • 0002 - Jump if register is greater than zero
    • 0003 - Jump always to memory address

• Set Register to Constant Format: 08 0000 00000000

  • Instruction Type
  • Register To Use
  • Constant

• Generic Format: 00 0000 0000 0000

  • Instruction Type
  • Register To Use
  • Memory/Register Address
  • Flags/Constant

######Instruction Types:

• 00
  • load
• 01
  • store
• 02
  • add
• 03
  • subtract
• 04
  • multiply
• 05
  • divide
• 06
  • rem
• 07
  • jump
• 08
  • set register to constant
• 09
  • no operation

• Updated the instruction set, added additional registers, added commands to print registers/memory

• Initial version, successfully runs a program to calculate the Fibonacci sequence.

• None