diff --git a/tft_fonts/pyfont.py b/tft_fonts/TFTfont.py
similarity index 63%
rename from tft_fonts/pyfont.py
rename to tft_fonts/TFTfont.py
index 81740c0..1556504 100644
--- a/tft_fonts/pyfont.py
+++ b/tft_fonts/TFTfont.py
@@ -1,5 +1,5 @@
 
-class PyFont(object):
+class TFTFont(object):
     def __init__(self, font, index, vert, horiz, nchars):
         self.firstchar = 32         # ord(first_character) Future use: absent from C file.
         self.nchars = nchars        # No. of chars in font
@@ -21,9 +21,32 @@ class PyFont(object):
         return self._index[offset] + (self._index[offset + 1] << 8)
 
     def get_ch(self, ch):
-        relch = max(0, ch - self.firstchar) # This is the behaviour you requested. In my view it should throw a ValueError.
-        if relch > self.nchars:
-            relch = 0
+        from uctypes import addrssof
+        relch = ch - self.firstchar
+        if relch > self.nchars or relch < 0:
+            raise ValueError('Character value {:} is unsupported.'.format(ch))
+        offset = self.get_idx(relch)
+        delta = self.get_idx(relch + 1) - offset
+        bv = self.bits_vert
+        mv = self.mv
+        if self.monospaced:
+            mv[: delta] = self._font[offset : offset + delta]
+            mv[delta : self.bytes_per_ch] = self._mvzero[delta : self.bytes_per_ch]
+            return addressof(self.char), self.bits_vert, delta, self.bits_horiz
+        else:
+            return addressof(self._font) + offset, self.bits_vert, delta, delta // self.bytes_vert
+
+# *************** TEST CODE ***************
+# This runs on a PC and allows font creation and cfonts_to_py.py to be tested without hardware
+# It can be deleted. Usage:
+# import fonts
+# fonts.fonts['freesans23x25'].render(0x41)
+# dict allows access to multiple fonts in fonts file
+
+    def get_ch_test(self, ch):
+        relch = ch - self.firstchar
+        if relch > self.nchars or relch < 0:
+            raise ValueError('Character value {:} is unsupported.'.format(ch))
         offset = self.get_idx(relch)
         delta = self.get_idx(relch + 1) - offset
         bv = self.bits_vert
@@ -32,15 +55,13 @@ class PyFont(object):
             bh = self.bits_horiz # Char width in bits
             mv[: delta] = self._font[offset : offset + delta]
             mv[delta : self.bytes_per_ch] = self._mvzero[delta : self.bytes_per_ch]
-            bh = self.bits_horiz
         else:
             mv[: delta] = self._font[offset : offset + delta]
             bh = delta // self.bytes_vert
         return bh # horizontal increment for character location
 
-# Demo/test of rendering to the REPL
     def render(self, ch): # enter with ord(ch)
-        bh = self.get_ch(ch)
+        bh = self.get_ch_test(ch)
         bv = self.bits_vert # Cache for speed
         mv = self.mv
         for bit_vert in range(bv):   # for each vertical line
diff --git a/tft_fonts/cfonts_to_py.py b/tft_fonts/cfonts_to_py.py
index aa0f144..09be21b 100755
--- a/tft_fonts/cfonts_to_py.py
+++ b/tft_fonts/cfonts_to_py.py
@@ -16,11 +16,6 @@
 # with a dictionary 'fonts.fonts' indexed by name and the value being a PyFont instance.
 # The name index is the font filename less path and extension
 
-# TODO check that new format below works for all cases of character line length as per inded
-# terminal7hex = b'\x08\x0C\x20\x80\x01'\
-# b'\x08\x00\x00\x3F\x00\x40\x80\x3F\x00\x00\x00\x0F\x80\x10\x40\x0F\x80'\
-# b'\x08\x00\x00\x3F\x00\x40\x80\x3F\x00\x00\x00\x08\x40\x1F\xC0\x00\x40'\
-
 import argparse, os
 
 def getname(sourcefile):
@@ -38,7 +33,7 @@ def rbits(n): # reverse bits in a byte
             n >>= 1
     return res
 
-# Given a string 0f form '0x23' representing a byte, return a string of same form but with the bits
+# Given a string 0f form '0x23' representing a byte, return a string of form 'xc4' with the bits
 # comprising the byte reversed
 def rbits_text(string):
     return 'x{:02x}'.format(rbits(int(string, 16)))
@@ -130,7 +125,7 @@ def process(infile, outfile, sourcefile):
                     outfile.write("b'")
                     for hexnum in nums:
                         outfile.write('\\')
-    #                   outfile.write(hexnum.strip()[1:4]) # Don't reverse bits
+#                        outfile.write(hexnum.strip()[1:4]) # Don't reverse bits
                         outfile.write(rbits_text(hexnum.strip()[0:4])) # reverse bits
                         hbit_bytes -= 1
                         if hbit_bytes == 0:
@@ -141,14 +136,14 @@ def process(infile, outfile, sourcefile):
     if phase == 4 :
         outfile.write("\n")
         write_index(outfile, name, index)
-        outfile.write('{:} = pyfont.PyFont(_{:}, _{:}_index, {}, {}, {})\n\n'.format(name, name, name, vert, horiz, chars_processed))
+        outfile.write('{:} = TFTfont.TFTFont(_{:}, _{:}_index, {}, {}, {})\n\n'.format(name, name, name, vert, horiz, chars_processed))
         print('{}: Characters in font: {} width: {} height: {}'.format(name, chars_processed, horiz, vert))
     else:
         print(''.join(("File: '", sourcefile, "' is not a valid C font file")))
 
 def write_header(outfile):
-    outfile.write('# Code generated by CfontToPython.py\n')
-    outfile.write('import pyfont\n')
+    outfile.write('# Code generated by cfonts_to_py.py\n')
+    outfile.write('import TFTfont\n')
   
 def write_trailer(sourcefiles, outfile):
     outfile.write('fonts = {')
@@ -169,10 +164,10 @@ def load_c(sourcefiles, destfile):
         print(err)
 
 if __name__ == "__main__":
-    parser = argparse.ArgumentParser(__file__, description=
+    parser = argparse.ArgumentParser(__file__, description =
        "Convert C fonts generated by GLCD font creator to Python.\nSample usage:\n ./cfonts_to_py Arial16x16.c ubuntu5x7.py\nProduces fonts.py")
-    parser.add_argument('infiles', metavar='N', type=str, nargs='+', help='input file paths')
-    parser.add_argument("--outfile", "-o", default='fonts.py', help="Path and name of output file", required=False)
+    parser.add_argument('infiles', metavar ='N', type = str, nargs = '+', help = 'input file paths')
+    parser.add_argument("--outfile", "-o", default = 'fonts.py', help = "Path and name of output file", required = False)
     args = parser.parse_args()
     errlist = [f for f in args.infiles if not f[0].isalpha()]
     if len(errlist):
@@ -181,4 +176,3 @@ if __name__ == "__main__":
             print(f)
     else:
         load_c(args.infiles, args.outfile)
-
diff --git a/tft_fonts/fonts.py b/tft_fonts/fonts.py
index f66c624..c83feb1 100644
--- a/tft_fonts/fonts.py
+++ b/tft_fonts/fonts.py
@@ -1,5 +1,5 @@
-# Code generated by CfontToPython.py
-import pyfont
+# Code generated by cfonts_to_py.py
+import TFTfont
 _freesans23x25 = b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'\
 b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x3f\xff\x70\x00\x3f\xfe\x70\x00'\
 b'\x00\x00\x00\x00\x1e\x00\x00\x00\x1f\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x1e\x00\x00\x00\x1f\x80\x00\x00'\
@@ -111,7 +111,7 @@ b'\x8c\x0e\xc0\x0e\xf0\x0e\x0c\x0f\x38\x0f\x50\x0f\x7c\x0f\xa8\x0f'\
 b'\xec\x0f\x18\x10\x44\x10\x70\x10\x88\x10\x94\x10\xb0\x10\xdc\x10'\
 b'\x24\x11\x24\x11'
 
-freesans23x25 = pyfont.PyFont(_freesans23x25, _freesans23x25_index, 25, 23, 96)
+freesans23x25 = TFTfont.TFTFont(_freesans23x25, _freesans23x25_index, 25, 23, 96)
 
 fonts = {"freesans23x25":freesans23x25,
 }