diff --git a/display.nim b/display.nim
new file mode 100644
index 0000000..0f8c7fa
--- /dev/null
+++ b/display.nim
@@ -0,0 +1,217 @@
+import input_type
+import map_type
+import turtle
+import turtle_type
+
+import math
+import sequtils
+import strutils
+import strformat
+import terminal
+import algorithm
+
+const blueCutoff = 0.05
+const cyanCutoff = 0.1
+const greenCutoff = 0.205
+const yellowCutoff = 0.335
+const redCutoff = 0.505
+const magentaCutoff = 1.0
+
+proc setHotnessBackground(hotness: float, maxHotness: float) =
+  if hotness == 0:
+    stdout.setBackgroundColor(bgDefault)
+  else:
+    let hotnessFrac = hotness / maxHotness
+    if hotnessFrac < blueCutoff:
+      stdout.setBackgroundColor(bgBlue)
+    elif hotnessFrac < cyanCutoff:
+      stdout.setBackgroundColor(bgCyan)
+    elif hotnessFrac < greenCutoff:
+      stdout.setBackgroundColor(bgGreen)
+    elif hotnessFrac < yellowCutoff:
+      stdout.setBackgroundColor(bgYellow)
+    elif hotnessFrac < redCutoff:
+      stdout.setBackgroundColor(bgRed)
+    else:
+      stdout.setBackgroundColor(bgMagenta)
+
+proc printHotmapLegend(maxHotness: float, x,y: int) =
+  template line(num: int) =  
+    setCursorPos(x, y + num - 1)
+  template showColor(col: BackgroundColor) =
+    stdout.setBackgroundColor(col)
+    stdout.write(" ")
+    stdout.setBackgroundColor(bgBlack)
+    stdout.write(" ")
+  
+  proc writeNumber(num: float) =
+    stdout.write(fmt"{num.int()}")
+
+  line(1)
+  showColor(bgDefault)
+  writeNumber(0.0)
+  
+  line(2)
+  showColor(bgBlue)
+  writeNumber(blueCutoff * maxHotness)
+
+  line(3)
+  showColor(bgCyan)
+  writeNumber(cyanCutoff * maxHotness)
+
+  line(4)
+  showColor(bgGreen)
+  writeNumber(greenCutoff * maxHotness)
+
+  line(5)
+  showColor(bgYellow)
+  writeNumber(yellowCutoff * maxHotness)
+
+  line(6)
+  showColor(bgRed)
+  writeNumber(redCutoff * maxHotness)
+
+  line(7)
+  showColor(bgMagenta)
+  writeNumber(magentaCutoff * maxHotness)
+  
+  
+
+proc displayGeneration*(generationNumber: int, timeSeconds: float, seed: int, input: Input, map: Map, turtles: var seq[Turtle]) =
+  
+  # SCREEN INIT
+  stdout.setBackgroundColor(bgBlack)
+  stdout.setForegroundColor(fgWhite)
+  eraseScreen()
+  setCursorPos(0, 0)
+
+  # STATISTICS
+  let scoreCount = turtles.len()
+  var scoreSum = 0
+  var stepsSum = 0
+  for turtle in turtles:
+    scoreSum += turtle.score
+    stepsSum += turtle.steps
+  
+  let scoreAvg = scoreSum.float() / scoreCount.float()
+  let stepsAvg = stepsSum.float() / scoreCount.float()
+
+  let variance = turtles.mapIt((it.score.float() - scoreAvg)^2).sum() / scoreCount.float()
+  let stddev = variance.sqrt()
+
+  # PRINT BASIC INFO
+  echo &"Generation number: {generationNumber}"
+  echo &"Computation time since last stop: {timeSeconds} s"
+  echo &"Seed: {seed}"
+  echo &"Population: {turtles.len()} turtles"
+  echo &"Mean score: {scoreAvg} (in {stepsAvg} steps)"
+  echo &"Standard deviation: {stddev}"
+  echo &"Top score: {turtles[0].score} (in {turtles[0].steps} steps)"
+
+  # PERCENTILS
+  turtles.sort(compareTurtles)
+  var percentils: seq[int] = @[]
+  for i in 1..9:
+    let index = (input.population div 10) * i
+    percentils.add(turtles[index].score)
+  let percentilsString = percentils.join(", ")
+  echo &"Score of every 10%th percentil: {percentilsString}"
+
+  # CHOOSE NOTABLE
+  var top10Paths: seq[Turtle] = @[]
+  var notables: seq[int] = @[]
+  var i = 0
+  while true:
+    if i > turtles.high():
+      break
+
+    if top10Paths.len() == 0 or top10Paths[top10Paths.high()].score != turtles[i].score:
+      top10Paths.add(turtles[i])
+      notables.add(i)
+    
+    if top10Paths.len() >= 10:
+      break
+
+    inc i
+  
+  let notableString = notables.join(", ")
+  echo &"Notable turtles: {notableString}"
+
+  # HOTNESS MAP
+  var hotness: seq[seq[int]] = @[]
+  var top10Hot: seq[seq[int]] = @[]
+  var topHot: seq[seq[int]] = @[]
+  for i in 0..input.size-1:
+    hotness.add(@[])
+    top10Hot.add(@[])
+    topHot.add(@[])
+    for j in 0..input.size-1:
+      hotness[i].add(0)
+      top10Hot[i].add(0)
+      topHot[i].add(0)
+  
+  template populateHotness(turtles: seq[Turtle], hotSeq: var seq[seq[int]], maxHot: var int) =
+    for turtle in turtles:
+      let path = turtle.path
+      for i in 0..path.xs.high():
+        let x = path.xs[i]
+        let y = path.ys[i]
+        hotSeq[y][x].inc()
+        if hotSeq[y][x] > maxHot:
+          maxHot = hotSeq[y][x]
+
+  var maxHotness = 0
+  populateHotness(turtles, hotness, maxHotness)
+  var maxTop10Hotness = 0
+  populateHotness(top10Paths, top10Hot, maxTop10Hotness)
+  var maxTopHotness = 0
+  populateHotness(@[turtles[0]], topHot, maxTopHotness)
+
+  # DISPLAY HOTNESS MAP
+  echo "Hotmap of All/Notable/Best Turtles"
+
+  const yOffset = 10
+  let xOffset = input.size + 2
+
+  for y in 0..input.size-1:
+    for x in 0..input.size-1:
+      let hotness = hotness[y][x]
+      let top10hotness = top10Hot[y][x]
+      let topHotness = topHot[y][x]
+      let symbol = map[y][x].tileToString()
+
+      # hotmap
+      setHotnessBackground(hotness.float(), maxHotness.float())
+      setCursorPos(x, y+yOffset)
+      stdout.write(symbol)
+
+      # top10 map
+      setHotnessBackground(top10hotness.float(), maxTop10Hotness.float())
+      setCursorPos(x+xOffset, y+yOffset)
+      stdout.write(symbol)
+
+      # top map
+      setHotnessBackground(topHotness.float(), maxTopHotness.float())
+      setCursorPos(x+2*xOffset, y+yOffset)
+      stdout.write(symbol)
+
+    
+    stdout.setBackgroundColor(bgBlack)
+    stdout.write("\n")
+
+  echo ""
+
+  # display legend
+  let legendYOffset = yOffset + 1 + input.size
+  printHotmapLegend(maxHotness.float(), 0, legendYOffset)
+  printHotmapLegend(maxTop10Hotness.float(), xOffset, legendYOffset)
+  printHotmapLegend(maxTopHotness.float(), 2*xOffset, legendYOffset)
+  echo ""
+  echo ""
+  # FINISH
+  echo "Press enter to continue."
+  discard stdin.readLine()
+  stdout.setBackgroundColor(bgDefault)
+  eraseScreen()
+  setCursorPos(1,1)
+  echo ""
diff --git a/input.json b/input.json
new file mode 100644
index 0000000..44a834c
--- /dev/null
+++ b/input.json
@@ -0,0 +1,8 @@
+{
+  "size": 19,
+  "treasure_count": 7,
+  "lifetime": 500,
+  "population": 500,
+  "instruction_set": "anybit",
+  "bits": 12
+}
\ No newline at end of file
diff --git a/input_type.nim b/input_type.nim
new file mode 100644
index 0000000..a6594f4
--- /dev/null
+++ b/input_type.nim
@@ -0,0 +1,11 @@
+
+type
+  Input* = object
+    size*: int
+    treasure_count*: int
+    lifetime*: int
+    population*: int
+    instruction_set*: string
+    bits*: int
+
+
diff --git a/instruction_sets/any_bit.nim b/instruction_sets/any_bit.nim
new file mode 100644
index 0000000..0f29d99
--- /dev/null
+++ b/instruction_sets/any_bit.nim
@@ -0,0 +1,105 @@
+import ../input_type
+import ../turtle_type
+import ../map_type
+import bitops
+import random
+
+const opcodeLength = 3
+# 3 if there are 8 different instructions
+
+# anybit
+proc genAnybitTurtle*(input: Input, bits: int): Turtle =
+  # generates a turtle of bits long memory cells
+  let maxAddress = (1 shl (bits - opcodeLength)) - 1
+  let maxValue = (1 shl bits) - 1
+
+  new(result)
+  for i in 0..maxAddress:
+    result.memory.add(rand(0..maxValue).uint32)
+
+proc executeAnybit*(instructionIndex: uint32, turtle: Turtle, map: Map, input: Input, bits: int): int =
+  let maxAddress = ((1 shl (bits - opcodeLength)) - 1).uint32
+  let maxValue = ((1 shl bits) - 1).uint32
+
+  var newInstructionIndex: uint32
+
+  let
+    icIncrement = 0'u64
+    icDecrement = (0b001 shl (bits-opcodeLength)).uint32
+    icJump =      (0b010 shl (bits-opcodeLength)).uint32
+    icMove =      (0b011 shl (bits-opcodeLength)).uint32
+    icDoubleMove = (0b100 shl (bits-opcodeLength)).uint32
+    icCond =      (0b101 shl (bits-opcodeLength)).uint32
+    icNand =     (0b110 shl (bits-opcodeLength)).uint32
+    icXor =     (0b111 shl (bits-opcodeLength)).uint32
+
+  let instruction = turtle.memory[instructionIndex]
+  let instructionCode = instruction.bitand(icXor)
+  let instructionArg = instruction.bitand(bitnot(icXor))
+
+  template addTo(target: var uint32, delta: uint32, subtract: bool = false) =
+    if subtract:
+      target = (target - delta).bitand(maxValue)
+    else:
+      target = (target + delta).bitand(maxValue)
+  
+  template nextBlock: uint32 =
+    turtle.memory[(instructionIndex + 1'u32).bitand(maxAddress)]
+  
+  template mapBounded(i: int): int =
+    max(min(i, input.size), 0)
+
+  if instructionCode == icIncrement:
+    turtle.memory[instructionArg].addTo(1)
+    newInstructionIndex = instructionIndex + 1'u32
+  elif instructionCode == icDecrement:
+    turtle.memory[instructionArg].addTo(1, subtract = true)
+    newInstructionIndex = instructionIndex + 1'u32
+  elif instructionCode == icJump:
+    newInstructionIndex = instructionArg
+  elif instructionCode == icMove:
+    let direction = instructionArg.bitand(3'u32)
+    if direction == 0'u32:
+      turtle.y += 1
+    elif direction == 1'u32:
+      turtle.y -= 1
+    elif direction == 2'u32:
+      turtle.x += 1
+    elif direction == 3'u32:
+      turtle.x -= 1
+    if turtle.x < 0 or turtle.y < 0 or turtle.x >= input.size or turtle.y >= input.size:
+      return -1
+    newInstructionIndex = instructionIndex + 1
+  elif instructionCode == icDoubleMove:
+    let amount = (instructionArg.bitand(28'u32) shr 2).int() + 1
+    let direction = instructionArg.bitand(3'u32)
+    if direction == 0'u32:
+      turtle.y += amount
+    elif direction == 1'u32:
+      turtle.y -= amount
+    elif direction == 2'u32:
+      turtle.x += amount
+    elif direction == 3'u32:
+      turtle.x -= amount
+    if turtle.x < 0 or turtle.y < 0 or turtle.x >= input.size or turtle.y >= input.size:
+      return -1
+    newInstructionIndex = instructionIndex + 1
+
+
+  elif instructionCode == icCond:
+    # jumps to address if the next block is even
+    if nextBlock().bitand(1'u32) == 0'u32:
+      newInstructionIndex = instructionArg
+    else:
+      newInstructionIndex = instructionIndex + 2
+  elif instructionCode == icNand:
+    # bitwise nand of the address with the next code block
+    turtle.memory[instructionArg] = bitnot(turtle.memory[instructionArg].bitand(nextBlock())).bitand(maxValue)
+    newInstructionIndex = instructionIndex + 2
+  elif instructionCode == icXor:
+    turtle.memory[instructionArg] = turtle.memory[instructionArg].bitxor(nextBlock()).bitand(maxValue)
+    newInstructionIndex = instructionIndex + 2
+  else:
+    raise newException(Defect, "Bad instruction code.")
+  
+  return newInstructionIndex.bitand(maxAddress).int()
diff --git a/main b/main
new file mode 100755
index 0000000..68be78c
Binary files /dev/null and b/main differ
diff --git a/main.nim b/main.nim
new file mode 100644
index 0000000..6f18822
--- /dev/null
+++ b/main.nim
@@ -0,0 +1,67 @@
+import strutils
+import json
+import random
+import times
+import os
+
+import input_type
+import map_type
+import turtle
+import turtle_type
+import score
+import select
+import mutate
+import display
+
+let now = getTime()
+var seed = now.toUnix * 1_000_000_000 + now.nanosecond
+if paramCount() > 0:
+  seed = parseInt(paramStr(1))
+
+randomize(seed)
+
+# first, get the inputs
+let input = readFile("input.json").parseJson().to(Input)
+
+if input.bits < 4 or input.bits > 32:
+  raise newException(Defect, "bits in input json must be between 4 and 32 (inclusive).")
+
+# get a map
+let map = input.generateMap()
+
+# get population turtles
+var turtles: seq[Turtle]
+for i in 0..input.population-1:
+  turtles.add(input.genTurtle())
+
+var lastTime = cpuTime()
+
+proc generation(generationNumber: int) =
+  # does a whole generation
+
+  # gets the path of the turtles
+  for turtle in turtles:
+    turtle.execute(map, input)
+    score(turtle, map, input)
+  
+  # display generation
+
+  if generationNumber mod 500 == 0:
+    let newTime = cpuTime()
+    let timeSeconds = newTime - lastTime
+    lastTime = newTime
+    displayGeneration(generationNumber, timeSeconds, seed.int(), input, map, turtles)
+  
+  turtles.select(input)
+  
+  # add mutated turtles from previous generation
+  let prevGenCount = turtles.high()
+  while turtles.len() < input.population:
+    let basis = turtles[rand(prevGenCount)]
+    turtles.add(mutate(basis, input))
+  
+
+var i = 0
+while true:
+  generation(i)
+  inc i
\ No newline at end of file
diff --git a/map_type.nim b/map_type.nim
new file mode 100644
index 0000000..05c4c86
--- /dev/null
+++ b/map_type.nim
@@ -0,0 +1,54 @@
+import strutils
+import sequtils
+import random
+
+import input_type
+
+type
+  Tile* = enum
+    tileEmpty, tileTreasure
+  Map* = seq[seq[Tile]]
+
+proc generateMap*(input: Input): Map =
+  let treasureCount = input.treasure_count
+
+  # create empty map
+  for i in 0..input.size:
+    result.add(@[])
+    for j in 0..input.size:
+      result[i].add(tileEmpty)
+  
+  # populate treasures
+  var addedTreasures = 0
+  while addedTreasures < treasureCount:
+    let randX = rand(input.size - 1)
+    let randY = rand(input.size - 1)
+    if result[randX][randY] == tileEmpty:
+      result[randX][randY] = tileTreasure
+      inc addedTreasures
+
+func tileToString*(tile: Tile): string =
+  case tile:
+  of tileEmpty:
+    " "
+  of tileTreasure:
+    "T"
+
+func lineToString*(line: seq[Tile]): string =
+  line.map(tileToString).join()
+
+proc mapToString*(map: Map): string =
+  map.map(lineToString).join("\n")
+
+proc printMap*(map: Map) =
+  map.mapToString().echo()
+
+func getTreasures*(map: Map): seq[(int, int)] =
+  var treasures: seq[(int, int)]
+
+  for y in 0..map.high():
+    for x in 0..map[0].high():
+      if map[y][x] == tileTreasure:
+        treasures.add((x, y))
+  
+  return treasures
diff --git a/mutate.nim b/mutate.nim
new file mode 100644
index 0000000..2af4c9f
--- /dev/null
+++ b/mutate.nim
@@ -0,0 +1,14 @@
+import turtle
+import turtle_type
+import input_type
+import random
+
+proc mutate*(turtle: Turtle, input: Input): Turtle =
+  # returns a mutated turtle
+  let newTurtle = genTurtle(input)
+
+  for i in 0..newTurtle.memory.high():
+    if rand(100) > 2:
+      newTurtle.memory[i] = turtle.memory[i]
+
+  return newTurtle
\ No newline at end of file
diff --git a/score.nim b/score.nim
new file mode 100644
index 0000000..2bdf019
--- /dev/null
+++ b/score.nim
@@ -0,0 +1,38 @@
+import map_type
+import input_type
+import turtle_type
+import math
+
+proc score*(turtle: Turtle, map: Map, input: Input) =
+  let path = turtle.path
+  # create a list of treasures
+  let treasures = map.getTreasures()
+
+  # create a list of distances from each treasure
+  var distances: seq[float] = @[]
+
+  for i in 0..treasures.high():
+    distances.add(-1.0)
+
+  # iterate through the path, and change the distance if it decreases
+  for i in 0..path.ys.high():
+    let x = path.xs[i]
+    let y = path.ys[i]
+    for j in 0..treasures.high():
+      let (tx, ty) = treasures[j]
+      let deltaX = abs(tx - x)
+      let deltaY = abs(ty - y)
+      # taxicab distance
+      let distance = (deltaX + deltaY).float()
+      if distances[j] < 0 or distance < distances[j]:
+        distances[j] = distance
+  
+  # every distance contributes to score, exponentially dropping off
+  # by the formula Ae^(-k * dist)
+  var treasureScore = 0.0
+  for distance in distances:
+    const A = 100.0
+    const k = 0.2
+    treasureScore += A * exp(- k * distance)
+  
+  turtle.score = treasureScore.int() - (turtle.steps div 5)
\ No newline at end of file
diff --git a/select.nim b/select.nim
new file mode 100644
index 0000000..b7979bf
--- /dev/null
+++ b/select.nim
@@ -0,0 +1,36 @@
+import random
+import math
+import algorithm
+
+import turtle
+import turtle_type
+import input_type
+
+proc select*(turtles: var seq[Turtle], input: Input) =
+  # sort turtles according to score
+  turtles.sort(compareTurtles)
+
+  var scoreSum = 0
+  for turtle in turtles:
+    scoreSum += turtle.score
+  let avgScore = scoreSum div turtles.len()
+
+  var survivors: seq[Turtle] = @[]
+
+  for i in 0..turtles.high():
+    let turtle = turtles[i]
+    const smoothness = 0.08
+    const chanceRandomLive = 0.02
+    const chanceRandomDie = 0.0
+    let chanceExp = exp(smoothness * float(turtles[i].score - avgScore))
+    let chance = chanceRandomLive + (1-chanceRandomDie-chanceRandomLive) * chanceExp / (chanceExp + 1)
+    if rand(1.0) < chance:
+      survivors.add(turtle)
+  
+  var i = 0
+  while i < turtles.len():
+    if turtles[i] notin survivors:
+      turtles.del(i)
+    else:
+      inc i
+    
diff --git a/turtle.nim b/turtle.nim
new file mode 100644
index 0000000..0adcc33
--- /dev/null
+++ b/turtle.nim
@@ -0,0 +1,75 @@
+import input_type
+import map_type
+import sequtils
+
+import turtle_type
+#import instruction_sets/eight_bit
+#import instruction_sets/ten_bit
+import instruction_sets/any_bit
+
+proc compareTurtles*(left, right: Turtle): int =
+  -cmp(left.score, right.score)
+
+# general:
+
+proc genTurtle*(input: Input): Turtle =
+  if input.instruction_set == "anybit":
+    return genAnybitTurtle(input, input.bits)
+  else:
+    raise newException(Defect, "Unknown instruction set.")
+
+proc executeInstruction(instructionIndex: int, turtle: Turtle, map: Map, input: Input): int =
+  if input.instruction_set == "anybit":
+    return executeAnybit(instructionIndex.uint32, turtle, map, input, input.bits)
+  else:
+    raise newException(Defect, "Unknown instruction set.")
+
+
+proc execute*(turtle: Turtle, map: Map, input: Input) =
+
+  let treasures = map.getTreasures()
+
+  # back to start
+  turtle.y = input.size div 2
+  turtle.x = input.size div 2
+  turtle.path.xs = @[]
+  turtle.path.ys = @[]
+  turtle.score = 0
+  turtle.found = repeat(false, treasures.len())
+  # save turtle original code
+  let turtleOriginalCode = turtle.memory
+
+  template tpath: Path =
+    turtle.path
+
+  proc markLocation: bool =
+    tpath.xs.add(turtle.x)
+    tpath.ys.add(turtle.y)
+    if map[turtle.y][turtle.x] == tileTreasure:
+      for i in 0..treasures.high():
+        let treasure = treasures[i]
+        if treasure[0] == turtle.x and treasure[1] == turtle.y:
+          turtle.found[i] = true
+        if turtle.found.allIt(it):
+          return true
+    return false
+
+  
+  discard markLocation()
+  
+  var instructionNumber = 0
+  var instructionIndex = 0
+  while instructionNumber < input.lifetime:
+    instructionIndex = executeInstruction(instructionIndex, turtle, map, input)
+    if instructionIndex == -1:
+      # out of bounds of map
+      break
+
+    if turtle.y != tpath.ys[tpath.ys.high()] or turtle.x != tpath.xs[tpath.xs.high()]:
+      if markLocation():
+        break
+    inc instructionNumber
+  
+  turtle.steps = instructionNumber
+  # restore original code
+  turtle.memory = turtleOriginalCode
diff --git a/turtle_type.nim b/turtle_type.nim
new file mode 100644
index 0000000..b7d9629
--- /dev/null
+++ b/turtle_type.nim
@@ -0,0 +1,13 @@
+type
+  Turtle* = ref object
+    memory*: seq[uint32]
+    x*: int
+    y*: int
+    score*: int
+    path*: Path
+    steps*: int
+    found*: seq[bool]
+  
+  Path* = object
+    xs*: seq[int]
+    ys*: seq[int]