diff --git a/distarray/globalapi/tests/test_distributed_io.py b/distarray/globalapi/tests/test_distributed_io.py
index b4a117e5..c95abdcf 100644
--- a/distarray/globalapi/tests/test_distributed_io.py
+++ b/distarray/globalapi/tests/test_distributed_io.py
@@ -45,7 +45,6 @@ def setUpClass(cls):
         cls.da = cls.context.empty(cls.distribution)
         cls.output_paths = cls.context.apply(engine_temp_path)
 
-    @unittest.skip("FIXME")
     def test_save_load_with_filenames(self):
 
         try:
@@ -57,7 +56,6 @@ def test_save_load_with_filenames(self):
             for filepath, target in zip(self.output_paths, self.context.targets):
                 self.context.apply(cleanup_file, (filepath,), targets=(target,))
 
-    @unittest.skip("FIXME")
     def test_save_load_with_prefix(self):
 
         output_path = self.output_paths[0]
diff --git a/distarray/localapi/format.py b/distarray/localapi/format.py
index c08c31a5..387ededd 100644
--- a/distarray/localapi/format.py
+++ b/distarray/localapi/format.py
@@ -56,6 +56,9 @@
 the magic number for ``.npy`` files, followed by the ``.npy`` header and
 array data.
 
+Notes
+-----
+
 The ``.npy`` format, including reasons for creating it and a comparison
 of alternatives, is described fully in the "npy-format" NEP and in the
 module docstring for ``numpy.lib.format``.
@@ -66,12 +69,9 @@
 from distarray.externals import six
 
 import numpy as np
-from numpy.lib.format import write_array_header_1_0
 from numpy.lib.utils import safe_eval
 from numpy.compat import asbytes
 
-from distarray.utils import _raise_nie
-
 
 MAGIC_PREFIX = asbytes('\x93DARRY')
 MAGIC_LEN = len(MAGIC_PREFIX) + 2
@@ -86,10 +86,12 @@ def magic(major, minor, prefix=MAGIC_PREFIX):
     ----------
     major : int in [0, 255]
     minor : int in [0, 255]
+    prefix : bytes
+        The magic prefix to concatenate with version number
 
     Returns
     -------
-    magic : str
+    magic : bytes
 
     Raises
     ------
@@ -101,15 +103,91 @@ def magic(major, minor, prefix=MAGIC_PREFIX):
         raise ValueError("Major version must be 0 <= major < 256.")
     if minor < 0 or minor > 255:
         raise ValueError("Minor version must be 0 <= minor < 256.")
+
+    return prefix + six.int2byte(major) + six.int2byte(minor)
+
+
+def read_magic(fp, prefix=MAGIC_PREFIX, prefix_len=MAGIC_LEN):
+    """Read the magic string to get the version of the file format.
+
+    Parameters
+    ----------
+    fp : filelike object
+    prefix : bytes
+        Magic prefix to look for
+    prefix_len : int
+        Number of bytes in `prefix`
+
+    Returns
+    -------
+    major : int
+    minor : int
+    """
+    magic_str = _read_bytes(fp, prefix_len, "magic string")
+    if magic_str[:-2] != prefix:
+        msg = "the magic string is not correct; expected %r, got %r"
+        raise ValueError(msg % (prefix, magic_str[:-2]))
+
     if six.PY2:
-        return prefix + chr(major) + chr(minor)
-    elif six.PY3:
-        return prefix + bytes([major, minor])
+        major, minor = map(ord, magic_str[-2:])
+    if six.PY3:
+        major, minor = magic_str[-2:]
+    return major, minor
+
+
+# mostly copied from numpy/lib/format
+# dependance on _filter_header removed, since we don't care about npz-style
+# headers
+def write_localarray_header(fp, d, version=None):
+    """Write the header for a localarray and return the version used
+
+    Parameters
+    ----------
+    fp : filelike object
+    d : dict
+        This has the appropriate entries for writing its string representation
+        to the header of the file.
+    version: tuple or None
+        None means use oldest that works
+        explicit version will raise a ValueError if the format does not
+        allow saving this data.  Default: None
+
+    Returns
+    -------
+    version : tuple of int
+        the file version which needs to be used to store the data
+    """
+    import struct
+    header = ["{"]
+    for key, value in sorted(d.items()):
+        # Need to use repr here, since we eval these when reading
+        header.append("'%s': %s, " % (key, repr(value)))
+    header.append("}")
+    header = "".join(header)
+    # Pad the header with spaces and a final newline such that the magic
+    # string, the header-length short and the header are aligned on a
+    # 16-byte boundary.  Hopefully, some system, possibly memory-mapping,
+    # can take advantage of our premature optimization.
+    current_header_len = MAGIC_LEN + 2 + len(header) + 1  # 1 for the newline
+    topad = 16 - (current_header_len % 16)
+    header = header + ' '*topad + '\n'
+    header = asbytes(header)
+
+    hlen = len(header)
+    if hlen < 256*256 and version in (None, (1, 0)):
+        version = (1, 0)
+        header_prefix = magic(1, 0) + struct.pack('<H', hlen)
     else:
-        raise _raise_nie()
+        msg = "Header length %s too big for version=%s"
+        msg %= (hlen, version)
+        raise ValueError(msg)
+
+    fp.write(header_prefix)
+    fp.write(header)
+    return version
 
 
-def write_localarray(fp, arr, version=(1, 0)):
+def write_localarray(fp, larr, version=(1, 0)):
     """
     Write a LocalArray to a .dnpy file, including a header.
 
@@ -122,7 +200,7 @@ def write_localarray(fp, arr, version=(1, 0)):
     fp : file_like object
         An open, writable file object, or similar object with a ``.write()``
         method.
-    arr : LocalArray
+    larr : LocalArray
         The array to write to disk.
     version : (int, int), optional
         The version number of the file format.  Default: (1, 0)
@@ -141,43 +219,16 @@ def write_localarray(fp, arr, version=(1, 0)):
         msg = "Only version (1, 0) is supported, not %s."
         raise ValueError(msg % (version,))
 
-    fp.write(magic(*version))
-
-    distbuffer = arr.__distarray__()
+    distbuffer = larr.__distarray__()
     metadata = {'__version__': distbuffer['__version__'],
                 'dim_data': distbuffer['dim_data'],
                 }
 
-    write_array_header_1_0(fp, metadata)
+    write_localarray_header(fp, metadata, version=(1, 0))
     np.save(fp, distbuffer['buffer'])
 
 
-def read_magic(fp):
-    """Read the magic string to get the version of the file format.
-
-    Parameters
-    ----------
-    fp : filelike object
-
-    Returns
-    -------
-    major : int
-    minor : int
-    """
-    magic_str = _read_bytes(fp, MAGIC_LEN, "magic string")
-    if magic_str[:-2] != MAGIC_PREFIX:
-        msg = "the magic string is not correct; expected %r, got %r"
-        raise ValueError(msg % (MAGIC_PREFIX, magic_str[:-2]))
-    if six.PY2:
-        major, minor = map(ord, magic_str[-2:])
-    elif six.PY3:
-        major, minor = magic_str[-2:]
-    else:
-        raise _raise_nie()
-    return major, minor
-
-
-def read_array_header_1_0(fp):
+def read_localarray_header(fp, version):
     """
     Read an array header from a filelike object using the 1.0 file format
     version.
@@ -188,6 +239,7 @@ def read_array_header_1_0(fp):
     ----------
     fp : filelike object
         A file object or something with a `.read()` method like a file.
+    version : tuple of int
 
     Returns
     -------
@@ -206,9 +258,12 @@ def read_array_header_1_0(fp):
     # Read an unsigned, little-endian short int which has the length of the
     # header.
     import struct
-    hlength_str = _read_bytes(fp, 2, "Array header length")
-    header_length = struct.unpack('<H', hlength_str)[0]
-    header = _read_bytes(fp, header_length, "Array header")
+    if version == (1, 0):
+        hlength_str = _read_bytes(fp, 2, "Array header length")
+        header_length = struct.unpack('<H', hlength_str)[0]
+        header = _read_bytes(fp, header_length, "Array header")
+    else:
+        raise ValueError("Invalid version %r" % version)
 
     # The header is a pretty-printed string representation of a literal Python
     # dictionary with trailing newlines padded to a 16-byte boundary. The keys
@@ -257,7 +312,7 @@ def read_localarray(fp):
         msg = "only support version (1,0) of file format, not %r"
         raise ValueError(msg % (version,))
 
-    __version__, dim_data = read_array_header_1_0(fp)
+    __version__, dim_data = read_localarray_header(fp, version=(1, 0))
 
     buf = np.load(fp)
 
diff --git a/distarray/localapi/tests/paralleltest_io.py b/distarray/localapi/tests/paralleltest_io.py
index 03a91e71..479a21bd 100644
--- a/distarray/localapi/tests/paralleltest_io.py
+++ b/distarray/localapi/tests/paralleltest_io.py
@@ -6,18 +6,19 @@
 
 import os
 import numpy
-import unittest
 
 from numpy.testing import assert_allclose, assert_equal
 from distarray.testing import ParallelTestCase, import_or_skip, temp_filepath
 from distarray.localapi import LocalArray, ndenumerate
 from distarray.localapi import (save_dnpy, load_dnpy, save_hdf5, load_hdf5,
-                             load_npy)
+                                load_npy)
 from distarray.localapi.maps import Distribution
 
 
 class TestDnpyFileIO(ParallelTestCase):
 
+    comm_size = 1
+
     def setUp(self):
         d = Distribution.from_shape(comm=self.comm, shape=(7,))
         self.larr0 = LocalArray(d)
@@ -46,14 +47,12 @@ def test_flat_file_save_with_file_object(self):
 
         self.assertTrue(magic == b'\x93DARRY')
 
-    @unittest.skip("FIXME")
     def test_flat_file_save_load_with_filename(self):
         save_dnpy(self.output_path, self.larr0)
         larr1 = load_dnpy(comm=self.comm, file=self.output_path)
         self.assertTrue(isinstance(larr1, LocalArray))
         assert_allclose(self.larr0, larr1)
 
-    @unittest.skip("FIXME")
     def test_flat_file_save_load_with_file_object(self):
         save_dnpy(self.output_path, self.larr0)
         with open(self.output_path, 'rb') as fp:
diff --git a/distarray/localapi/tests/test_format.py b/distarray/localapi/tests/test_format.py
new file mode 100644
index 00000000..e7d7e852
--- /dev/null
+++ b/distarray/localapi/tests/test_format.py
@@ -0,0 +1,57 @@
+# encoding: utf-8
+# ---------------------------------------------------------------------------
+#  Copyright (C) 2008-2014, IPython Development Team and Enthought, Inc.
+#  Distributed under the terms of the BSD License.  See COPYING.rst.
+# ---------------------------------------------------------------------------
+
+
+import unittest
+import six
+
+from distarray.localapi import format as fmt
+
+
+class TestMagic(unittest.TestCase):
+
+    def test_magic_0(self):
+        expected = six.b('\x93DARRY\x03\x02')
+
+        prefix = six.b('\x93DARRY')
+        major = 3
+        minor = 2
+
+        result = fmt.magic(major=major, minor=minor, prefix=prefix)
+        self.assertEqual(result, expected)
+
+    def test_magic_1(self):
+        expected = six.b('\x93NUMPY\x01\x00')
+
+        prefix = six.b('\x93NUMPY')
+        major = 1
+        minor = 0
+
+        result = fmt.magic(major=major, minor=minor, prefix=prefix)
+        self.assertEqual(result, expected)
+
+
+class TestReadMagic(unittest.TestCase):
+
+    def test_read_magic_0(self):
+        prefix = six.b('\x93DARRY')
+        prefix_len = 8
+        fp = six.BytesIO(six.b('\x93DARRY\x03\x02'))
+
+        major, minor = fmt.read_magic(fp, prefix=prefix, prefix_len=prefix_len)
+
+        expected = (3, 2)
+        self.assertEqual((major, minor), expected)
+
+    def test_read_magic_1(self):
+        prefix = six.b('\x93NUMPY')
+        prefix_len = 8
+        fp = six.BytesIO(six.b('\x93NUMPY\x01\x01'))
+
+        major, minor = fmt.read_magic(fp, prefix=prefix, prefix_len=prefix_len)
+
+        expected = (1, 1)
+        self.assertEqual((major, minor), expected)
diff --git a/distarray/testing.py b/distarray/testing.py
index e25f4986..201682d4 100644
--- a/distarray/testing.py
+++ b/distarray/testing.py
@@ -20,7 +20,6 @@
 from distarray.externals import six
 from distarray.externals import protocol_validator
 from distarray.globalapi.context import Context, ContextCreationError
-from distarray.globalapi.ipython_utils import IPythonClient
 from distarray.error import InvalidCommSizeError
 from distarray.localapi.mpiutils import MPI, create_comm_of_size
 
diff --git a/quickstart b/quickstart
index f7a6c7ef..dcd24513 100755
--- a/quickstart
+++ b/quickstart
@@ -88,7 +88,7 @@ resolve_conda() {
 }
 
 install_osx() {
-    conda create -n $CONDA_ENV python=$PY_VER numpy ipyparallel notebook cython sphinx mock matplotlib
+    conda create -n $CONDA_ENV python=$PY_VER numpy ipyparallel notebook cython sphinx=1.3 mock matplotlib
     source activate $CONDA_ENV
     pip install mpi4py
     pip install sphinxcontrib-programoutput
@@ -98,7 +98,7 @@ install_osx() {
 }
 
 install_linux() {
-    conda create -n $CONDA_ENV python=$PY_VER mpi4py numpy ipyparallel notebook cython sphinx mock matplotlib
+    conda create -n $CONDA_ENV python=$PY_VER mpi4py numpy ipyparallel notebook cython sphinx=1.3 mock matplotlib
     source activate $CONDA_ENV
     pip install sphinxcontrib-programoutput
     python setup.py $INSTALL_MODE