diff --git a/error.cc b/error.cc
index ce56202..af38042 100644
--- a/error.cc
+++ b/error.cc
@@ -1,6 +1,7 @@
 /**
  * error.c: Generic error/debug routines 
  * author: Vassil Roussev
+ * from sdhash -- sdhash.org 
  */
 
 #include <errno.h>
@@ -46,21 +47,3 @@ void *realloc_check( void *buffer, uint64_t new_size) {
     return mem_chunk;
 }
 
-/**
- * Print a 256-byte buffer
- */
-void print256( const uint8_t *buffer) {
-    uint16_t i;
-    fprintf( stderr, "      ");
-    for( i=0; i<32; i++)
-        fprintf( stderr, "%02x ", i);
-    fprintf( stderr, "\n");
-    
-    for( i=0; i<256; i++) {
-        if( i % 32 == 0)
-            fprintf( stderr, "%04x: ", i);
-        fprintf( stderr, "%02x ", buffer[i]);
-        if( i % 32 == 31)
-            fprintf( stderr, "\n");
-    }
-}
diff --git a/map_file.cc b/map_file.cc
index 2a1d602..a9a580c 100644
--- a/map_file.cc
+++ b/map_file.cc
@@ -1,3 +1,7 @@
+/** 
+    sdhash file processing code via sdhash.org under apache license
+    lightly modified by @candicenonsense
+*/
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
diff --git a/nullfinder.cc b/nullfinder.cc
index 5b4eb14..a0d99bf 100644
--- a/nullfinder.cc
+++ b/nullfinder.cc
@@ -1,12 +1,12 @@
 
 /** File: nullfinder.cc
     Author: Candice Quates 
-    Program: gpunullfinder
+    Program: nullfinder
 
     Takes argument of a file of dumped gpu memory, attempts to divine structure 
     by searching for blocks of nulls which have been added for padding. 
-    Default block of nulls to search for is 8.  extracting is only working 
-    for 8-null blocks.  Not reporting really really short (1-2 byte blocks)
+    Default block of nulls to search for is 8.  Much larger blocks are
+    sometimes helpful
 
     File parsing code lifted from sdhash, apache license (Roussev/Quates 2013)
     General structure and command line arguments lifted from zsniff. (apache license)
@@ -26,7 +26,7 @@ g++ -std=c++0x -o nullf nullfinder.cc map_file.cc error.cc
 
 
 
-#define VERSION "nullfind 0.2 by Candice Quates July 2015"
+#define VERSION "nullfinder 0.2 by Candice Quates July 2015"
 
 
 #include "util.h"
diff --git a/util.h b/util.h
index 58cd21b..8a33208 100644
--- a/util.h
+++ b/util.h
@@ -1,3 +1,8 @@
+/**
+utilities file from sdhash, used for file reading,
+under apache license sdhash.org
+*/
+
 /*
  * General definitions (Vassil Roussev)
  */
@@ -29,7 +34,6 @@ typedef struct {
 
 processed_file_t *process_file(const char *fname);
 
-void print256( const uint8_t *buffer);
 void *alloc_check( uint32_t alloc_type, uint64_t mem_bytes, const char *fun_name, const char *var_name, uint32_t error_action);
 void *realloc_check( void *buffer, uint64_t new_size);