diff --git a/README.md b/README.md
index 44d2e4f..70ac78b 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,7 @@ Installation section).
 
 ```python
     >>> import bap
-    >>> print '\n'.join(insn.asm for insn in bap.disasm("\x48\x83\xec\x08"))
+    >>> print '\n'.join(insn.asm for insn in bap.disasm(b"\x48\x83\xec\x08"))
         decl    %eax
         subl    $0x8, %esp
 ```
diff --git a/src/bap/adt.py b/src/bap/adt.py
index bb9311f..02129d9 100755
--- a/src/bap/adt.py
+++ b/src/bap/adt.py
@@ -182,7 +182,10 @@ def count_authors(library):
 
 """
 
-from collections import Iterable,Sequence,Mapping
+try:
+    from collections.abc import Iterable,Sequence,Mapping
+except ImportError:
+    from collections import Iterable,Sequence,Mapping
 
 class ADT(object):
     """Algebraic Data Type.
diff --git a/src/bap/bir.py b/src/bap/bir.py
index fd28140..e33e2b2 100644
--- a/src/bap/bir.py
+++ b/src/bap/bir.py
@@ -2,7 +2,10 @@
 
 """BIR - BAP Intermediate Representation"""
 
-from collections import Sequence,Mapping
+try:
+    from collections.abc import Sequence,Mapping
+except ImportError:
+    from collections import Sequence,Mapping
 from .adt import *
 from .bil import *
 from . import noeval_parser
@@ -245,7 +248,16 @@ class Attrs(Map) :
 class Attr(ADT) :
     """Attribute is a pair of attribute name and value,
     both represented with str"""
-    pass
+
+    @property
+    def name(self):
+        """name of attribute"""
+        return self.arg[0]
+
+    @property
+    def value(self):
+        """value of attribute"""
+        return self.arg[1]
 
 class Values(Map) :
     """A set of possible values, taken by a phi-node.
@@ -253,7 +265,9 @@ class Values(Map) :
     It is a mapping from the tid of a preceeding block,
     to an expression that denotes a value.
     """
-    pass
+    def __init__(self, *args):
+        super(Map, self).__init__(args) # pylint: disable=bad-super-call
+        self.elements = dict(args[0])
 
 class Tid(ADT) :
     """Tid(id,name=None) term unique identifier.
@@ -357,7 +371,15 @@ class Annotation(ADT) :
     Each annotation denotes an association between a memory region and
     some arbitrary property, denoted with an attribute.
     """
-    pass
+    @property
+    def region(self):
+        """memory region"""
+        return self.arg[0]
+
+    @property
+    def attr(self):
+        """memory region attribute"""
+        return self.arg[1]
 
 def parse_addr(str):
     return int(str.split(':')[0],16)
diff --git a/src/bap/noeval_parser.py b/src/bap/noeval_parser.py
index c22bb64..b1940a7 100755
--- a/src/bap/noeval_parser.py
+++ b/src/bap/noeval_parser.py
@@ -2,23 +2,32 @@
 '''
 Parser for ADT string from bap that does not use eval
 
-The nieve eval-based version runs into out-of-memory conditions on large files
+The naive eval-based version runs into out-of-memory conditions on large files
 '''
 import gc
 import sys
 import time
 
-# NOTE: uses bap.bir, but cannot import at module level (circular references)
+from subprocess import check_output
+
+# bap.1.3 breaks the format of the following types.  it prints hexes
+# without prefixing them with the `0x` escape. To fix it without
+# fixing bap, we will treat integers inside this parents as
+# hexadecimals if there is no prefix.
+BROKEN_TYPES = [
+    'Section',
+    'Region'
+]
 
+# NOTE: uses bap.bir, but cannot import at module level (circular references)
 
-def toint(string, start, end):
+def toint(string, start, end, base=10):
     '''
     Convert substring string[start:end] to integer/long without eval
 
     Note: may contain leading whitespace
     '''
     istr = string[start:end].lstrip()
-
     if sys.version_info > (3,): # then longs don't exist
         if istr.endswith('L'):
             istr = istr.rstrip('L')
@@ -31,7 +40,7 @@ def toint(string, start, end):
     if istr.startswith('0x'):
         return of_str(istr, 16)
     else:
-        return of_str(istr)
+        return of_str(istr, base)
 
 def setup_progress(totalitems):
     '''
@@ -159,17 +168,19 @@ def _parse_end(in_c, in_s, i, objs, stk):
         raise ParserInputError('Mismatched input stream')
     j = stk[-1]
     parent = objs[j]
+    ptyp = parent['typ']
     assert isinstance(parent, dict)
     assert parent, 'parent is empty'
-    assert parent['typ'] != 'int', 'parent wrong type: %r' % (parent['typ'])
+    assert ptyp != 'int', 'parent wrong type: %r' % (parent['typ'])
     assert 'children' in parent
     if top: # add to parent if non empty
         # make real int before appending
         if top['typ'] == 'd': # int
             try:
-                top = toint(in_s, k, i)
+                base = 16 if ptyp in BROKEN_TYPES else 10
+                top = toint(in_s, k, i, base)
             except ValueError:
-                raise ParserInputError("Integer expected between [%d..%d)" % (top, i))
+                raise ParserInputError("Integer expected between [%d..%d)" % (k, i))
         parent['children'].append(top)
     if in_c == ',': # add blank object and move on
         # next obj
@@ -179,7 +190,6 @@ def _parse_end(in_c, in_s, i, objs, stk):
         return i
     else: # we are ending a tuple/list/app do it
         # maybe handle apply (num and seq are earlier)
-        ptyp = parent['typ']
         if ptyp == '[':
             if in_c != ']':
                 raise ParserInputError('close %r and open %r mismatch' % (in_c, ptyp))
@@ -325,4 +335,3 @@ def parser(input_str, disable_gc=False, logger=None):
     'format': 'adt',
     'load': parser
 }
-
diff --git a/src/bap/rpc.py b/src/bap/rpc.py
index 8ac0c1b..a6a5663 100644
--- a/src/bap/rpc.py
+++ b/src/bap/rpc.py
@@ -112,11 +112,11 @@ def load(self):
         if self.msg is None:
             self.msg = self.bap.get_resource(self.ident)
             if not self._name in self.msg:
-                if 'error' in msg:
+                if 'error' in self.msg:
                     raise ServerError(response)
                 else:
                     msg = "Expected {0} msg but got {1}".format(
-                        self._name, msg)
+                        self._name, self.msg)
                     raise RuntimeError(msg)
 
     def get(self, child):
@@ -126,7 +126,7 @@ def get(self, child):
 
 class Project(Resource):
     def __init__(self, ident, bap):
-        super(Image,self).__init__('program', ident, bap)
+        super(Image,self).__init__('program', ident, bap) # pylint: disable=bad-super-call
 
     def load_program(self):
         self.program = bir.loads(self.get('program'))
@@ -171,7 +171,7 @@ def load_symbols(self):
 
     def get_symbol(self, name, d=None):
         try:
-            return (s for s in self.symbols if s.name == name).next()
+            return next(s for s in self.symbols if s.name == name)
         except StopIteration:
             return d
 
@@ -214,8 +214,8 @@ def __init__(self, mem, parent):
 
     def load_data(self):
         try:
-            url = (urlparse(url) for url in self.links
-                   if urlparse(url).scheme == 'mmap').next()
+            url = next(urlparse(url) for url in self.links
+                   if urlparse(url).scheme == 'mmap')
             qs = parse_qs(url.query)
             offset = int(qs['offset'][0])
             with open(url.path, "rw+b") as f:
@@ -266,8 +266,8 @@ def __init__(self, server={}):
         self.last_id = 0
         for attempt in range(RETRIES):
             try:
-                self.capabilities = self.call({'init' : {
-                    'version' : '0.1'}}).next()['capabilities']
+                self.capabilities = next(self.call({'init' : {
+                    'version' : '0.1'}}))['capabilities']
                 break
             except Exception:
                 if attempt + 1 == RETRIES:
@@ -278,7 +278,7 @@ def __init__(self, server={}):
         if not "capabilities" in self.__dict__:
             raise RuntimeError("Failed to connect to BAP server")
         self.data = {}
-        self.temp = NamedTemporaryFile('rw+b', prefix="bap-")
+        self.temp = NamedTemporaryFile('w+b', prefix="bap-")
 
     def insns(self, src, **kwargs):
         req = {'resource' : src}
@@ -300,7 +300,7 @@ def load_file(self, name):
             'url' : 'file://' + name}})
 
     def get_resource(self, name):
-        return self.call({'get_resource' : name}).next()
+        return next(self.call({'get_resource' : name}))
 
     def load_chunk(self, data, **kwargs):
         kwargs.setdefault('url', self.mmap(data))
@@ -341,14 +341,13 @@ def mmap(self, data):
         return url
 
     def _load_resource(self, res):
-        rep = self.call(res).next()
+        rep = next(self.call(res))
         if 'error' in rep:
             raise ServerError(rep)
         return Id(rep['resource'])
 
-
 def jsons(r, p=0):
-    dec = json.JSONDecoder(encoding='utf-8')
+    dec = json.JSONDecoder()
     while True:
         obj,p = dec.scan_once(r.text,p)
         yield obj
diff --git a/tests/test_low_level_interface.py b/tests/test_low_level_interface.py
new file mode 100644
index 0000000..261097f
--- /dev/null
+++ b/tests/test_low_level_interface.py
@@ -0,0 +1,13 @@
+import unittest
+import bap
+
+class TestLowLevelInterface(unittest.TestCase):
+
+    def test_low_level_interface(self):
+        asm_str = '\n'.join(insn.asm for insn in bap.disasm(b"\x48\x83\xec\x08"))
+        self.assertIsNotNone(asm_str)
+        self.assertIn("\tdecl\t%eax", asm_str)
+        self.assertIn("\tsubl\t$0x8, %esp", asm_str)
+
+if __name__ == "__main__":
+    unittest.main()
\ No newline at end of file