VOLVE 5.0

Glossary

Some terms and concepts used by the simulator software.

Code Block - Part of a KFORTH program. Each row of the kforth program is a code block. The first code block is labeled 'main()', and is where program execution begins. Other code blocks are labeled by their row number. I.e., 'row5'. Learn about the kforth languge here.

Program Counter - (pc). This is the offset into the code block. Taken together (cb, pc) forms a complete address referring to a KFORTH program memory location.

Universe - refers to the overall simulation. But it can also refer to the grid in which all the cells and other blocks are located.

Organism - The simulator manages a list of organisms. The organism object contains a KFORTH genetic program and a list of cells which are all part of this organism and running the same program.

Cell - The simulator manages a list of cells. Only cells run programs and are given simulation time. Every time the simulator is called (See UNIVERSE_Simulate()) it executes 1 instruction from the next cell in the list. And then the next cell and so on. When all cells are simulated, we return to the beginning.

Spore - Spores are special cells placed on the grid. They are shown in light blue. They contain the genetic KFORTH program of the cell that created them. Spores can be fertilized with a second genetic program. After merging and mutating a new organism is spawned and added to the list of cells.

Organic Material - This is the name given to a simple block on the grid that just contains some energy. Organic Material blocks appear in the simulation windows as white blocks with a black border. Organic blocks can be created by the instruction MAKE-ORGANIC. But usually an organic block is created when an organism dies or parts of the orgasism dies and the disconnected cells are converted to organic material.
Organic material is a resource, as it can be EAT'en which provides energy.

Barrier - The simulation universe can be broken up into regions by placing barriers around the grid. The barriers are simply blocks which cannot be moved through. There is an instruction to create barriers, MAKE-BARRIER, but this is often protected because during evolution is ruins the simulation. Too many barriers get created. The MAKE-BARRIER instruction should be protected and used as part of a custom simulation.

Energy - Many cells on the grid have energy. All energy is conserved during the execution of the simulator. This is accomplished by always moving energy from one cell to another, never creating or destroying it.
Energy is required to exist as an organism with cpu cycles. This can be used to control the simulation from getting too many organisms and grinding to a halt.

Very few operations require energy. The GROW, MAKE-SPORE, and SPAWN instructions do. They also have mode settings to specify how much energy is required.

The instructions which take energy are EAT and SEND-ENERGY. EAT is a more generic and friendly interface to the eating operation. It has tons of modes to control how much eating occurs. Or how aggressive it is. SEND-ENERGY is a lower level operation. It just moves the amount of energy specified between cells. This instruction can be used to implement your own rules.

KFORTH - Stands for Ken's Forth. It is the programming language used by this simulator. The cell's are controlled by KFORTH programs which determine the behaviors of the cells. Kforth derives from the language known as forth. It is a 16-bit architecture with the ability to address 256 MB of memory. It has TRAP's for implementing system calls. It has interupts. It has protected mode and user land mode.

KFORTH Program - A program written in KFORTH. The seed file provided for each Strain Profile is a kforth program. Kforth programs are stored in files as plain text. Usually the file extension is .kf.

Stack, Data - A data structure inside of each cell for storing the results of the program execution. The stack is fixed size, with a length of 64 elements. When full the cell cannot push new items on the stack and all instructions behave like NO-OP's

Stack, Call - Another data structure inside of each cell. This stores the prior program location (cb, pc) for returning from subroutines. This stack is limited to 64 elements. When full, no more subroutines can be called.

Radio Active Tracer - This is a fancy name for marking things in the simulation. They are marked with a green outline which looks radio-active. It is analogous to tracer chemicals/isotopes used in real medicine. The idea is to see where an organism goes and observe all of its offspring.

Selected Organism - This is the organism the user has selected in the simulation window.

Instruction - A KFORTH program consists of numbers and instructions. An instruction is one of about 160 built-in primitives of the simulator. Examples of instructions are, + - / negate dup pop ifelse, TRAP9, OMOVE.

Strain - Evolve 5.0 supports 8 strains within the same simulation. These strains are numbered 0 to 7. A strain is a collection of customizations.

Strain Profile - A strain that has been saved for re-use. It is given a name and is stored in the users ~/.evolve5rc file.

Evolve Preferences - A file to hold strain profiles and other application data ~/.evolve5rc

Mutate Program - The process by which a KFORTH program is modifed during copying. Mutations are one or more small random modifications to the program.

Merge Program - Two program can be merged by merging the code blocks. Interlacing them or randomly interlacing them are posible modes.

Normalized Coordinate - (x,y) coordinate which refer to the immediate neighboring cells. These are coordinate with the values -1, 0, and 1. Such as (-1, 0), (0, 1), (1, 1), etc...

Normalized Vector - Similar to a Normalize Coordinate except the important information is the direction, not the neighboring square. So for example the normalized vector (1, 1) refers to the direction north and east (up and to the left).

Seed - A value used to initialize the random number generator at the creation of the simulation.

Seed Program - A KFORTH program that is used as the starting program for an initial organism in a new simulation.

Starting Population - Refers to how many organisms you want to start the simulation with.

Simulation Steps - Refers to how many times the C API routine UNIVERSE_Simulate() has been called. This API will simulate 1 cell for 1 instruction.

Age, of Universe - Refers to the number of times the universe has simulated every cell in the cell list. This increments slower than the Step variable.

Age, of Organism - Refers to the age of an organism. One of each organisms properties is how many steps it has been alive. This value is incremented each time all of its cells have been simulated for 1 step.

Register - Each cell has 10 registers for storing temporary values. These registers hold a 16-bit signed value. There are instrutions to increment and decrement registers.

Protected Code Block - A code block in the protected region of the KFORTH program. A protected code block will not be mutated. Nor will information leak out of it during mutations. And other properties that allow for sandboxing custom code from evolving code.

Protected Instruction - An instruction which has been marked "protected" by ther user. These instructions will not be generated by the mutation algorithm. They can be used in the protected region and made unavailable to the evolving code.

KFORTH Program Literal - A number stored in the program memory. NOTE: This is a 15-bit signed value. Program Literals are 15-bits... Deal with it. They are stored in the same space as the instructions.

KFORTH Opcode - An instruction stored in the program memory. See the instructions OPCDOE, OPCODE!, OPCODE'.

KFORTH Instruction - Same term as "KFORTH Opcode".

Trap - A trap is a way for un-protected code to call out to protected code. Traps use code block rows: row1, row2, ... row9. Instructions: TRAP1 thru TRAP9 call the code blocks row1 thru row9.

Interrupt - Alters the execution flow control for a cell to a TRAP handler. The condition that triggers an Interrupt is due to another cell execution an instruciton which affects another cell. Interrupts must be enabled by setting mode bits.

Instruction Modes - Many important instructions, such a EAT, SEND, MAKE-SPORE, and SPAWN, can have their behavior altered. You use Instruction Modes to do this. They consists of one or more switched which can be independently turned on/off. Each strain can configure these mode bits independently of each other.