diff --git a/spectre.c b/spectre.c
index 9c7a521..0074379 100644
--- a/spectre.c
+++ b/spectre.c
@@ -1,14 +1,30 @@
+/* spectre.c - CVE-2017-5715 user-to-user sucess rate measurement
+ *
+ * Borrows code from 
+ *  - https://gist.github.com/ErikAugust/724d4a969fb2c6ae1bbd7b2a9e3d4bb6
+ *  - https://github.com/genua/meltdown
+ *
+ * Copyright (c) 2022 Samuel AUBERTIN
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <getopt.h>
 #include <string.h>
-#ifdef _MSC_VER
-#include <intrin.h> /* for rdtscp and clflush */
-#pragma optimize("gt",on)
-#else
 #include <x86intrin.h> /* for rdtscp and clflush */
-#endif
 
 #if defined(__i386__) || defined(__amd64__)
 #define CACHELINESIZE	64
@@ -226,7 +242,7 @@ main(
 	size_t 		malicious_x = (size_t)(secret - (char * ) array1); /* default for malicious_x */
 	int 		i, score[2], len = (int)strlen(secret);
   	uint8_t 	value[2];
-  	unsigned 	sucesses = 0;
+  	unsigned 	successes = 0;
   	
 	while ((o = getopt(argc, argv, "t:vc")) != EOF) {
 		switch (o) {
@@ -242,8 +258,10 @@ main(
 			default:
 			usage:
 				fprintf(stderr, "usage: %s [-v] [-c] "
-			    "[-t threshold]\n", argv[0]);
-				return 2;
+			    "[-t threshold]\n\t-v\t\tverbose\n"
+                            "\t-c\t\tcalibrate only\n"
+                            "\t-t\t\tfixed threshold, in milliseconds\n", argv[0]);
+				return 1;
 		}
 	}
 	if (argc != optind)
@@ -258,14 +276,16 @@ main(
 	while (--len >= 0) {
 		leak(malicious_x++, value, score, cache_hit_threshold);
 		if(score[0] == 3 && value[0] > 31 && value[0] < 127) {
-			sucesses++;
+			successes++;
 			fprintf(stderr, "\033[32m%c\033[0m", (value[0]));
 		} else {
 			fprintf(stderr, "\033[31m?\033[0m");
 		}	
 	}
 	fprintf(stderr, "\n");
-	printf("%s: %.0f %%\n", argv[0] + 2, 100 * sucesses / (float)strlen(secret));
+	printf("%s:\tsuccess= %.0f %%\tthreshold= %d ms\n", 
+                argv[0] + 2,
+                100 * successes / (float)strlen(secret), cache_hit_threshold);
 	
 	return 0;
 }