diff --git a/airpower/draw.py b/airpower/draw.py
index f30948b5..b8588ce7 100644
--- a/airpower/draw.py
+++ b/airpower/draw.py
@@ -7,6 +7,12 @@
 
 import airpower.azimuth as apazimuth
 
+def setcanvas(x, y):
+  matplotlib.rcParams['figure.figsize'] = [x, y]
+  plt.figure()
+  plt.axis('equal')
+  plt.axis('off')
+
 def cosd(x):
   return np.cos(np.radians(x))
 def sind(x):
@@ -113,44 +119,3 @@ def drawaircraft(x, y, facing, name, altitude, when):
   drawdart(x, y, facing, dy=-0.02, size=0.5, color=color)
   drawtext(x, y, facing, name, dx=-0.3, dy=0.0, size=7, color=color)
   drawtext(x, y, facing, "%2d" % altitude, dx=+0.3, dy=0.0, size=7, color=color)
-
-def drawhexgrid(sx, sy, nx, ny):
-  matplotlib.rcParams['figure.figsize'] = [nx, ny * np.sqrt(3/4)]
-  plt.figure()
-  plt.axis('equal')
-  plt.axis('off')
-  for ix in range(sx, sx + nx):
-    for iy in range(sy, sy + ny):
-      drawhex(ix, iy + 0.5 * (ix % 2))
-
-def numbertohex(n):
-
-  # The hexes in the TSOH maps are numbered as XXYY, where XX is the column number and YY is the row number, in this sense:
-  #
-  #     0201
-  # 0101    0301
-  #     0202
-  # 0102    0302
-  #     0203
-  # 0103    0303
-
-  x = n // 100
-  y = - (n % 100)
-  if x % 2 == 1:
-    y -= 0.5
-  return x, y
-
-def drawhexnumber(n):
-  drawtext(*numbertohex(n), 90, "%04d" % n, dy=0.3, size=7, color="grey")
-
-def drawmapA1():
-  drawhexgrid(11,-16,19,15)
-  for x in range(11,30):
-    for y in range(1,16):
-      drawhexnumber(x * 100 + y)
-
-def drawmapC1():
-  drawhexgrid(51,-16,19,15)
-  for x in range(51,70):
-    for y in range(1,16):
-      drawhexnumber(x * 100 + y)
diff --git a/airpower/maps.py b/airpower/maps.py
new file mode 100644
index 00000000..1803dc59
--- /dev/null
+++ b/airpower/maps.py
@@ -0,0 +1,145 @@
+import airpower.draw as apdraw
+
+import math
+
+import matplotlib
+import matplotlib.pyplot as plt
+matplotlib.rcParams['figure.figsize'] = [7.5, 10]
+plt.rcParams.update({'font.size': 10})
+
+_maps = []
+_nxmaps = 0
+_nymaps = 0
+
+def setmaps(maps, verbose=True):
+
+  global _maps
+  global _nymaps
+  global _nxmaps
+
+  # The maps argument follows visual layout, so we need to flip it vertically 
+  # so that the lower-left map has indices (0,0).
+  _maps = list(reversed(maps))
+  _nymaps = len(maps)
+  _nxmaps = len(maps[0])
+
+  if verbose:
+    for iy in range (0, _nymaps):
+      print("%s" % " ".join(maps[iy]))
+
+# x0 and y0 are the hex coordinates of the lower left hex.
+
+def _mapx0(map):
+  for iy in range (0, _nymaps):
+    for ix in range (0, _nxmaps):
+      if map == _maps[iy][ix]:
+        return ix * 20
+  raise ValueError("map %s is not in use." % map)
+
+def _mapy0(map):
+  for iy in range (0, _nymaps):
+    for ix in range (0, _nxmaps):
+      if map == _maps[iy][ix]:
+        return iy * 15
+  raise ValueError("map %s is not in use." % map)
+
+# xx0 and yy0 are the components of the hex number of the lower left hex.
+  
+def _mapxx0(map):
+  mapletter = map[0]
+  if mapletter == "A":
+    return 11
+  elif mapletter == "B":
+    return 31
+  elif mapletter == "C":
+    return 51
+  else:
+    raise "invalid map %s." % map
+
+def _mapyy0(map):
+  mapnumber = map[1]
+  if mapnumber == "1":
+    return 15
+  elif mapnumber == "2":
+    return 30
+  else:
+    raise "invalid map %s." % map
+
+def numbertomap(n):
+
+  xx = n // 100
+  yy = n % 100
+
+  if 11 <= xx and xx <= 30:
+    mapletter = "A"
+  elif 31 <= xx and xx <= 50:
+    mapletter = "B"
+  elif 51 <= xx and xx <= 70:
+    mapletter = "C"
+  else:
+    raise ValueError("invalid map number %d." % n)
+
+  if xx % 2 == 1 and 1 <= yy and yy <= 15:
+    mapnumber = "1"
+  elif xx % 2 == 0 and 2 <= yy and yy <= 16:
+    mapnumber = "1"
+  elif xx % 2 == 1 and 16 <= yy and yy <= 30:
+    mapnumber = "2"
+  elif xx % 2 == 0 and 17 <= yy and yy <= 31:
+    mapnumber = "2"
+  else:
+    raise ValueError("invalid map number %d." % n)
+
+  return mapletter + mapnumber
+
+def numbertohex(n):
+
+  map = numbertomap(n)
+
+  xx = n // 100
+  yy = n % 100
+
+  dx = xx - _mapxx0(map)
+  dy = _mapyy0(map) - yy
+  if xx % 2 == 0:
+    dy += 0.5
+
+  x0 = _mapx0(map)
+  y0 = _mapy0(map)
+
+  return x0 + dx, y0 + dy
+
+def _drawmap(map):
+  xx0 = _mapxx0(map)
+  yy0 = _mapyy0(map)
+  for ix in range(xx0, xx0 + 20):
+    if ix % 2 == 1:
+      for iy in range(yy0 - 14, yy0 + 1):
+        n = ix * 100 + iy
+        x, y = numbertohex(n)
+        apdraw.drawhex(x, y)
+        apdraw.drawtext(x, y, 90, "%04d" % n, dy=0.3, size=7, color="grey")
+    else:
+      for iy in range(yy0 - 13, yy0 + 2):
+        n = ix * 100 + iy
+        x, y = numbertohex(n)
+        apdraw.drawhex(x, y)
+        apdraw.drawtext(x, y, 90, "%04d" % n, dy=0.3, size=7, color="grey")
+
+  x0, y0 = numbertohex(100 * xx0 + yy0)
+
+  apdraw.drawtext(x0, y0, 90, map, dy=-0.05, size=12, color="grey")
+
+  apdraw.drawline(x0 -  0.5, y0 -  0.5, x0 + 19.5, y0 -  0.5, color="grey")
+  apdraw.drawline(x0 -  0.5, y0 -  0.5, x0 -  0.5, y0 + 14.5, color="grey")
+  apdraw.drawline(x0 -  0.5, y0 + 14.5, x0 + 19.5, y0 + 14.5, color="grey")
+  apdraw.drawline(x0 + 19.5, y0 -  0.5, x0 + 19.5, y0 + 14.5, color="grey")
+
+def drawmaps():
+
+  apdraw.setcanvas(_nxmaps * 20, _nymaps * math.sqrt(3/4) * 15)
+
+  for iy in range (0, _nymaps):
+    for ix in range (0, _nxmaps):
+      if _maps[iy][ix] != "--":
+        _drawmap(_maps[iy][ix])