diff --git a/src/helper.c b/src/helper.c
index cb3502f..1705794 100644
--- a/src/helper.c
+++ b/src/helper.c
@@ -45,7 +45,7 @@ void makeHexDump(bool base_2, uint16_t ram[])
 
     time(&timer);
     tm_timer=localtime(&timer);
-    if(strftime(timestamp,sizeof(timestamp),"coredump_%d_%b_%y_%T.toy",tm_timer)==0)
+    if(strftime(timestamp,sizeof(timestamp),"coredump_%d_%b_%y_%H-%M-%S.toy",tm_timer)==0)
     {
         fprintf(stderr,"Buffer for system-time fault! hexdump canceled\n");
         return;
diff --git a/src/main.c b/src/main.c
index 166ac8a..f272daa 100644
--- a/src/main.c
+++ b/src/main.c
@@ -22,8 +22,8 @@ int main(int argc, char *argv[])
     bool        run = true;     //CPU halt and reset.(Nb: make a coredump beforehand)
 
     printf("\n+++++++++++++++++++++++++++++++++++++++++++++++\n+Boot: "CPU_TYPE
-    " with %zu x %zu Bit RAM.+\n+++++++++++++++++++++++++++++++++++++++++++++++\n\n"
-    ,(sizeof(ram)/sizeof(ram[0])),sizeof(ram[0])*8);
+    " with %lu x %lu Bit RAM.+\n+++++++++++++++++++++++++++++++++++++++++++++++\n\n"
+    ,(unsigned long)(sizeof(ram)/sizeof(ram[0])),(unsigned long)sizeof(ram[0])*8);
 
     if(initialise_ram(ram,argc,argv)==-1) return 1;     /*load data from command line into RAM
                                                         (-1 in case of error,