diff --git a/examples/fbmirror.py b/examples/fbmirror.py
index 99bd3b4..d6a670d 100644
--- a/examples/fbmirror.py
+++ b/examples/fbmirror.py
@@ -17,6 +17,7 @@ import numpy as np
 
 import adafruit_blinka_raspberry_pi5_piomatter as piomatter
 import adafruit_blinka_raspberry_pi5_piomatter.click as piomatter_click
+from adafruit_blinka_raspberry_pi5_piomatter.pixelmappers import simple_multilane_mapper
 
 with open("/sys/class/graphics/fb0/virtual_size") as f:
     screenx, screeny = [int(word) for word in f.read().split(",")]
@@ -55,7 +56,7 @@ def make_pixelmap_multilane(width, height, n_addr_lines, n_lanes):
 @piomatter_click.standard_options(n_lanes=2, n_temporal_planes=4)
 def main(xoffset, yoffset, width, height, serpentine, rotation, pinout, n_planes, n_temporal_planes, n_addr_lines, n_lanes):
     if n_lanes != 2:
-        pixelmap = make_pixelmap_multilane(width, height, n_addr_lines, n_lanes)
+        pixelmap = simple_multilane_mapper(width, height, n_addr_lines, n_lanes)
         geometry = piomatter.Geometry(width=width, height=height, n_planes=n_planes, n_addr_lines=n_addr_lines, n_temporal_planes=n_temporal_planes, n_lanes=n_lanes, map=pixelmap)
     else:
         geometry = piomatter.Geometry(width=width, height=height, n_planes=n_planes, n_addr_lines=n_addr_lines, n_temporal_planes=n_temporal_planes, rotation=rotation)
diff --git a/examples/rainbow_spiral_active3.py b/examples/rainbow_spiral_active3.py
index 941fb96..555c40f 100644
--- a/examples/rainbow_spiral_active3.py
+++ b/examples/rainbow_spiral_active3.py
@@ -15,6 +15,7 @@ import rainbowio
 from PIL import Image, ImageDraw
 
 import adafruit_blinka_raspberry_pi5_piomatter as piomatter
+from adafruit_blinka_raspberry_pi5_piomatter.pixelmappers import simple_multilane_mapper
 
 width = 64
 n_lanes = 6
@@ -22,25 +23,10 @@ n_addr_lines = 5
 height = n_lanes << n_addr_lines
 pen_radius = 1
 
-def make_pixelmap_multilane(width, height, n_addr_lines, n_lanes):
-    calc_height = n_lanes << n_addr_lines
-    if height != calc_height:
-        raise RuntimeError(f"Calculated height {calc_height} does not match requested height {height}")
-    n_addr = 1 << n_addr_lines
-
-    m = []
-    for addr in range(n_addr):
-        for x in range(width):
-            for lane in range(n_lanes):
-                y = addr + lane * n_addr
-                m.append(x + width * y)
-    return m
-
-
 canvas = Image.new('RGB', (width, height), (0, 0, 0))
 draw = ImageDraw.Draw(canvas)
 
-pixelmap = make_pixelmap_multilane(width, height, n_addr_lines, n_lanes)
+pixelmap = simple_multilane_mapper(width, height, n_addr_lines, n_lanes)
 geometry = piomatter.Geometry(width=width, height=height, n_addr_lines=n_addr_lines, n_planes=10, n_temporal_planes=4, map=pixelmap, n_lanes=n_lanes)
 framebuffer = np.asarray(canvas) + 0  # Make a mutable copy
 matrix = piomatter.PioMatter(colorspace=piomatter.Colorspace.RGB888Packed,
diff --git a/pyproject.toml b/pyproject.toml
index adf1357..f90c314 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,5 +18,6 @@ lint.extend-select = [
 ]
 lint.extend-ignore = [
   "E501",   # Line too long
+  "RUF002",   # Yes I meant to type 'multiplication sign'!
 ]
 target-version = "py311"
diff --git a/src/adafruit_blinka_raspberry_pi5_piomatter/pixelmappers.py b/src/adafruit_blinka_raspberry_pi5_piomatter/pixelmappers.py
new file mode 100644
index 0000000..70877b2
--- /dev/null
+++ b/src/adafruit_blinka_raspberry_pi5_piomatter/pixelmappers.py
@@ -0,0 +1,29 @@
+def simple_multilane_mapper(width, height, n_addr_lines, n_lanes):
+    """A simple mapper for 4+ pixel lanes
+
+    A framebuffer (width × height) is mapped onto a matrix where the lanes are stacked
+    top-to-bottom. Panels within a lane may be cascaded left-to-right.
+
+    Rotation is not supported, and neither are more complicated arrangements of panels
+    within a single chain (no support for serpentine or stacked panels within a segment)
+
+    .. code-block:: raw
+
+        0 -> [panel] -> [panel]
+        1 -> [panel] -> [panel]
+        2 -> [panel] -> [panel]
+    """
+
+    calc_height = n_lanes << n_addr_lines
+    if height != calc_height:
+        raise RuntimeError(f"Calculated height {calc_height} does not match requested height {height}")
+    n_addr = 1 << n_addr_lines
+
+    m = []
+    for addr in range(n_addr):
+        for x in range(width):
+            for lane in range(n_lanes):
+                y = addr + lane * n_addr
+                m.append(x + width * y)
+    print(m)
+    return m