diff --git a/board.py b/board.py
new file mode 100644
index 0000000..89bf7c7
--- /dev/null
+++ b/board.py
@@ -0,0 +1,154 @@
+#!/usr/bin/env python3
+# todo list:
+# - fix all the todos in the document
+# - move 'position' data to its own class with dynamic conversion between
+
+class Board:
+    unplayed = 0
+    cross = 1
+    nought = 2
+    mappings = {
+            'a': 0,
+            'b': 1,
+            'c': 2,
+            'd': 3,
+            'e': 4,
+            'f': 5,
+            'g': 6,
+            'h': 7,
+            'i': 8,
+    }
+    reverse = {i[1]:i[0] for i in mappings.items()}
+    def __init__(self):
+        self.board = [[[
+            [Board.unplayed for i in range(3)] for j in range(3)
+        ] for k in range(3) ] for l in range(3) ]
+        self.movestring = []
+        self.turn = Board.cross
+    def push(self, movestring):
+        pos = self.translateGlobal(movestring)
+        self.movestring.append(movestring)
+        self.board[pos[0]][pos[1]][pos[2]][pos[3]] = self.turn
+
+        if self.turn == Board.cross:
+            self.turn = Board.nought
+        else:
+            self.turn = Board.cross
+    def subboardWin(self, x, y):
+        b = self.board
+        for i in range(3):
+            if b[x][y][i][0] == b[x][y][i][1] == b[x][y][i][2]:
+                if b[x][y][i][0] != Board.unplayed:
+                    return b[x][y][i][0]
+            if b[x][y][0][i] == b[x][y][1][i] == b[x][y][2][i]:
+                if b[x][y][0][i] != Board.unplayed:
+                    return b[x][y][0][i]
+        if b[x][y][0][0] == b[x][y][1][1] == b[x][y][2][2]:
+            if b[x][y][0][0] != Board.unplayed:
+                return b[x][y][0][0]
+        if b[x][y][2][0] == b[x][y][1][1] == b[x][y][0][2]:
+            if b[x][y][2][0] != Board.unplayed:
+                return b[x][y][2][0]
+        return Board.unplayed
+    def allEmpty(self):
+        buf = []
+        for i in range(3):
+            for j in range(3):
+                for k in range(3):
+                    for l in range(3):
+                        if self.board[i][j][k][l] == Board.unplayed:
+                            buf.append(self.translateLocal((i, j, k, l)))
+    def possibleMoves(self):
+        # get last move
+        try:
+            lastpos = self.movestring[-1]
+        except IndexError:
+            # if no moves have been made, return the whole board
+            ret = []
+            for i in range(9):
+                for j in range(9):
+                    buf = []
+                    buf.append(Board.reverse[i])
+                    buf.append(str(j))
+                    ret.append(''.join(buf))
+
+            return ret
+
+        # get global tuple
+        lastpos = self.translateGlobal(lastpos)
+        # check for a subboard win condition in the indicated
+        # position; if so, just return self.allEmpty()
+
+        # WARNING: this will select positions in already won boards that are empty
+        # needs to be fixed
+        if self.subboardWin(lastpos[0], lastpos[1]):
+            return self.allEmpty()
+
+        # get all squares in metasquare
+        # this doesn't work because it's getting the *current* square
+        # and not the square the move is referring to
+        # this needs to be fixed
+        square = self.returnInSquare(self.movestring[-1])
+        buf = []
+        for i in square:
+            # if empty, we can move
+            if self.isEmpty(i):
+                buf.append(i)
+
+        return buf
+    def translateGlobal(self, movestring):
+        globcoords = (
+                Board.mappings[movestring[0]],
+                int(movestring[1]) - 1,
+        )
+
+        subboard = (
+                int(globcoords[0] / 3),
+                int(globcoords[1] / 3),
+        )
+
+        localpos = (
+                globcoords[0] % 3,
+                globcoords[1] % 3,
+        )
+
+        return (subboard[0], subboard[1], localpos[0], localpos[1])
+
+    def translateLocal(self, globaltuple):
+        globcoords = (
+                globaltuple[0] * 3 + globaltuple[2],
+                globaltuple[1] * 3 + globaltuple[3] + 1,
+        )
+
+        movestring = []
+        movestring.append(Board.reverse[globcoords[0]])
+        movestring.append(str(globcoords[1]))
+
+        return ''.join(movestring)
+
+    def returnInSquare(self, movestring, convert=True):
+        orig = self.translateGlobal(movestring)
+        buf = []
+        for i in range(3):
+            for j in range(3):
+                buf.append((orig[0], orig[1], i, j))
+
+        if convert:
+            rbuf = []
+            for i in buf:
+                rbuf.append(Board.translateLocal(self, i))
+
+            return rbuf
+
+        return buf
+    def isEmpty(self, movestring):
+        orig = self.translateGlobal(movestring)
+        item = self.board[orig[0]][orig[1]][orig[2]][orig[3]]
+        if item == Board.unplayed:
+            return True
+        return False
+    def isFull(self, movestring):
+        return not self.isEmpty(movestring)
+    def getInnerBoard(self, x, y):
+        pass
+