diff --git a/README.rst b/README.rst
index 913a42a..e89e86a 100644
--- a/README.rst
+++ b/README.rst
@@ -255,6 +255,40 @@ optional). MAC/65 is a macro assembler originally designed for the Atari 8-bit
 machines but since it produces 6502 code it can be used to compile for any
 machine that uses the 6502: Apple, Commodore, etc.
 
+Creating Atari 8-bit Executables
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Atari 8-bit object files include a small header and an arbitrary number of
+segments, each with a start and end address. As the file is read, segment data
+is placed in memory in the order they occur on disk, so there is no requirement
+that the segments be written to memory in any order and segments do not have to
+be contiguous.
+
+This example creates a new XEX on a disk that combines the segments of an
+already existing executable with some new assembly code.
+
+After creating the test image with::
+
+    $ atrcopy test.atr create dos2sd
+    using dos2sd template:
+      Atari 8-bit DOS 2 single density (90K), empty VTOC
+    created test.atr: ATR Disk Image (size=92160 (720x128b), crc=0 flags=0 unused=0) Atari DOS Format: 707 usable sectors (707 free), 0 files
+
+this command compiles the file ``test_header.s`` and prefixes it to the
+existing executable::
+
+    $ atrcopy test.atr asm -s test_header.s -b air_defense_v18.xex -o test.xex -f
+    test.atr: ATR Disk Image (size=92160 (720x128b), crc=0 flags=0 unused=0) Atari DOS Format: 707 usable sectors (707 free), 0 files
+    fname: test_header.s
+    Pass 1: Success. (0 warnings)
+    Pass 2: 
+    adding 0600 - 0653, size=0053 ($53 bytes @ 0600) from test_header.s assembly
+    adding 02e2 - 02e4, size=0002 ($2 bytes @ 02e2) from test_header.s assembly
+    adding  $02e0-$02e2 ($0002 @ $0006) from air_defense_v18.xex
+    adding  $6000-$6bd4 ($0bd4 @ $000c) from air_defense_v18.xex
+    total file size: $c3d (3133) bytes
+    copying test.xex to test.atr
+
 
 Creating DOS 3.3 Binaries
 ~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/atrcopy/__init__.py b/atrcopy/__init__.py
index 0f16f75..0c1c99f 100644
--- a/atrcopy/__init__.py
+++ b/atrcopy/__init__.py
@@ -192,6 +192,7 @@ def assemble(image, source_files, data_files, obj_files, run_addr=""):
         for first, last, object_code in asm.segments:
             s = segments.add_segment(object_code, first)
             log.debug("  %s" % s.name)
+            print "adding %s from %s assembly" % (s, name)
     for name in data_files:
         if "@" not in name:
             raise AtrError("Data files must include a load address specified with the @ char")
diff --git a/atrcopy/ataridos.py b/atrcopy/ataridos.py
index d15f08b..821890e 100644
--- a/atrcopy/ataridos.py
+++ b/atrcopy/ataridos.py
@@ -651,7 +651,7 @@ class AtariDosDiskImage(DiskImageBase):
 
     def create_executable_file_image(self, segments, run_addr=None):
         base_segment, user_segments = get_xex(segments, run_addr)
-        return base_segment, "XEX"
+        return base_segment.data, "XEX"
 
 
 class BootDiskImage(AtariDosDiskImage):
diff --git a/test_data/test_header.s b/test_data/test_header.s
new file mode 100644
index 0000000..b33c81f
--- /dev/null
+++ b/test_data/test_header.s
@@ -0,0 +1,29 @@
+SDLSTL	= $0230 
+CONSOL	= $D01F 
+;
+	*= $0600 
+;
+INIT
+	LDA #<TITLEDL
+	STA SDLSTL
+	LDA #>TITLEDL
+	STA SDLSTL+1 
+	LDA #8 
+	STA CONSOL
+TTL0	LDA CONSOL
+	CMP #6 
+	BNE TTL0
+	RTS 
+;
+TITLESC
+	.SBYTE +$80 ,"   PRESS START TO   "
+	.SBYTE +$C0 ,"  CONTINUE LOADING  "
+;
+TITLEDL	.BYTE $70 ,$70 ,$70
+	.BYTE $70 ,$70 ,$70 ,$70 ,$70 ,$70 ,$70 ,$70 ,$70 ,$70 ,$47 
+	.WORD TITLESC
+	.BYTE 6 ,$41 
+	.WORD TITLEDL
+
+	*= $02E2 
+	.WORD INIT