diff --git a/doc/em/assem.nr b/doc/em/assem.nr
index db18e8efa..6231f2c2c 100644
--- a/doc/em/assem.nr
+++ b/doc/em/assem.nr
@@ -634,7 +634,7 @@ GROUP 3 \- INTEGER ARITHMETIC
   RMI \*w :	Remainder (*)
   NGI \*w :	Negate (two's complement) (*)
   SLI \*w :	Shift left (*)
-  SRI \*w :	Shift right (*)
+  SRI \*w :	Shift right
 .DE
 
 .DS
diff --git a/fast/driver/driver.c b/fast/driver/driver.c
index c0e70f8b1..25c2107c3 100644
--- a/fast/driver/driver.c
+++ b/fast/driver/driver.c
@@ -152,7 +152,7 @@ const struct system_information machine_info[2] =
 		}}
 #else
 #ifdef FM2
-		/* pc Flags */
+		/* modula-2 Flags */
 		{1, {
 		   "-Vw2.2i2.2l4.2p2.2f8.2S2.2"
 		}}
@@ -207,7 +207,7 @@ const struct system_information machine_info[2] =
 		}}
 #else
 #ifdef FM2
-		/* pc Flags */
+		/* modula-2 Flags */
 		{1, {
 		   "-Vw2.2i2.2l4.2p4.2f8.2S2.2"
 		}}
@@ -221,7 +221,6 @@ const struct system_information machine_info[2] =
 struct arglist CPP_FLAGS = {0,{NULL}};
 
 
-
 struct arglist LD_HEAD =
 { 2,
 { "$H/lib/$S/head_em",
@@ -298,12 +297,12 @@ static int cv_flag = 0;
 char *mkstr(char *, ...);
 static char *alloc(unsigned int);
 static char *extension(char *);
-static char *expand_string(char *);
+static char *expand_string(char *s, struct system_information *);
 static void error(char *, char *, char *);
 static void warning(char *, char *, char *);
 static void panic(char *);
 static void append(register struct arglist *, char *);
-static void expand(register struct arglist *);
+static void expand(register struct arglist *, struct system_information *);
 static void concat(struct arglist *, struct arglist *);
 static int runvec(struct arglist *, char *);
 static int needsprep(char *);
@@ -345,6 +344,12 @@ void trapcc(int sig)
 #define comp_name()	"$H/lib/ack/em_pc"
 #endif /* FPC */
 
+/** Default library directories to search in. */
+
+#define LIB_DIR_1		"$H/share/ack/$S"
+#define LIB_DIR_2		"$H/lib/ack/plat/$S"
+
+
 #ifdef FCC
 int lang_opt(char *str)
 {
@@ -524,6 +529,8 @@ char* search_library_path(struct stringlist *dirs, char* lib)
 	return NULL;
 }
 
+
+
 int main(int argc, char *argv[])
 {
 	/* Contains the directories being searched for libraries */
@@ -574,11 +581,16 @@ int main(int argc, char *argv[])
 	sys_basename(*argv++, ProgCall);
 
 	/* get compiler to use. */
-	COMP = expand_string(comp_name());
+	COMP = expand_string(comp_name(),sys_info);
 	/* get c pre-processor to use */
-	CPP = expand_string(CPP_NAME);
+	CPP = expand_string(CPP_NAME,sys_info);
 	/** get linker to use */
-	LD = expand_string(sys_info->linker);
+	LD = expand_string(sys_info->linker,sys_info);
+
+	/* Add system directory path. */
+	stringlist_add(&library_dirs,expand_string(LIB_DIR_1,sys_info));
+	stringlist_add(&library_dirs,expand_string(LIB_DIR_2,sys_info));
+
 
 
 	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
@@ -682,6 +694,9 @@ int main(int argc, char *argv[])
 	{
 		append(&COMP_FLAGS, sys_info->compiler_flags.al_argv[count]);
 	}
+#ifdef FPC
+	append(&COMP_FLAGS, "-d");
+#endif
 
 	/* Now for each srcfile, if it starts with -l then replace it with the correct real
 	 * path immediately.
@@ -734,12 +749,12 @@ int main(int argc, char *argv[])
 	}
 
 #ifdef FM2
-	INCLUDE = expand_string("-I$H/lib/m2");
+	INCLUDE = expand_string("-I$H/lib/m2",sys_info);
 #endif /* FM2 */
 #ifdef FCC
 /*	INCLUDE = expand_string(
 			ansi_c ? "-I$H/include/tail_ac" : "-I$H/include/_tail_cc"); */
-	INCLUDE = expand_string("-I$H/share/ack/include");
+	INCLUDE = expand_string("-I$H/share/ack/include",sys_info);
 /*	append(&COMP_FLAGS, "-L");*/
 #endif /* FCC */
 	count = SRCFILES.al_argc;
@@ -912,7 +927,7 @@ int main(int argc, char *argv[])
 		if (cv_flag)
 		{
 			init(call);
-			append(call, expand_string(sys_info->cv));
+			append(call, expand_string(sys_info->cv, sys_info));
 			append(call, tmp_file);
 			append(call, o_FILE);
 			if (runvec(call, (char *) 0)==EXIT_FAILURE)
@@ -959,7 +974,7 @@ static char * alloc(unsigned int u)
 	return p;
 }
 
-static char * expand_string(char *s)
+static char * expand_string(char *s, struct system_information *sysinfo)
 {
 	char buf[1024];
 	register char *p = s;
@@ -986,10 +1001,10 @@ static char * expand_string(char *s)
 				strcpy(q, ackhome);
 				break;
 			case 'M':
-				strcpy(q, MACHNAME);
+				strcpy(q, sysinfo->arch);
 				break;
 			case 'S':
-				strcpy(q, SYSNAME);
+				strcpy(q, sysinfo->platform);
 				break;
 			default:
 				panic("internal error");
@@ -1018,14 +1033,14 @@ static void append(register struct arglist *al, char *arg)
 	al->al_argv[(al->al_argc)++] = arg;
 }
 
-static void expand(register struct arglist *al)
+static void expand(register struct arglist *al, struct system_information *sysinfo)
 {
 	register int i = al->al_argc;
 	register char **p = &(al->al_argv[0]);
 
 	while (i-- > 0)
 	{
-		*p = expand_string(*p);
+		*p = expand_string(*p,sysinfo);
 		p++;
 	}
 }
diff --git a/util/int/do_array.c b/util/int/do_array.c
index 62112fbd7..9f850d4c7 100644
--- a/util/int/do_array.c
+++ b/util/int/do_array.c
@@ -58,12 +58,13 @@ PRIVATE void arr(int type, /* operation TYPE */
 {
 	register ptr desc = dppop();	/* array DESCriptor */
 	register size obj_size;		/* OBJect SIZE */
-	register long diff =		/* between index and lower bound */
-		spop(elm_size) - mem_lds(desc, elm_size);
+	long index = spop(elm_size);
+	long diff =		/* between index and lower bound */
+		index - mem_lds(desc, elm_size);
 	register ptr arr_addr = dppop();/* ARRay ADDRess */
 
 	if (must_test && !(IgnMask&BIT(EARRAY))) {
-		if (diff < 0 || diff > mem_lds(desc + elm_size, elm_size)) {
+		if (diff < 0 || index > mem_lds(desc + elm_size, elm_size)) {
 			trap(EARRAY);
 		}
 	}
diff --git a/util/int/do_intar.c b/util/int/do_intar.c
index e80f1ee3f..df81f5511 100644
--- a/util/int/do_intar.c
+++ b/util/int/do_intar.c
@@ -14,7 +14,7 @@
 #include	"text.h"
 #include	"fra.h"
 
-PRIVATE long adi(long, long, size), sbi(long, long, size), dvi(long, long);
+PRIVATE long adi(long, long, size), sbi(long, long, size), dvi(long, long, size);
 PRIVATE long mli(long, long, size), rmi(long, long), ngi(long, size);
 PRIVATE long sli(long, long, size), sri(long, long, size);
 
@@ -55,7 +55,7 @@ void DoDVI(register size l)
 
 	LOG(("@I6 DoDVI(%ld)", l));
 	spoilFRA();
-	npush(dvi(spop(l), t), l);
+	npush(dvi(spop(l), t, l), l);
 }
 
 /** RMI w: Remainder (*) */
@@ -162,7 +162,7 @@ PRIVATE long mli(long w1, long w2, size nbytes)
 	return (w1 * w2);
 }
 
-PRIVATE long dvi(long w1, long w2)
+PRIVATE long dvi(long w1, long w2, size nbytes)
 {
 	if (w2 == 0) {
 		if (!(IgnMask&BIT(EIDIVZ))) {
@@ -170,6 +170,17 @@ PRIVATE long dvi(long w1, long w2)
 		}
 		else	return (0L);
 	}
+
+	/* Check for division overflow. */
+	if ((w1 == i_mins(nbytes)) && (w2 == -1))
+	{
+		if (must_test && !(IgnMask&BIT(EIOVFL)))
+		{
+			trap(EIOVFL);
+		} else return i_mins(nbytes);
+	}
+
+
 	return (w1 / w2);
 }
 
@@ -212,11 +223,20 @@ PRIVATE long sli(long w1, long w2, size nbytes)
 	
 		if (!(IgnMask&BIT(EIOVFL))) {
 			/* check overflow */
-			if (	(w1 >= 0 && (w1 >> (nbytes*8 - w2)) != 0)
-			||	(w1 < 0 && (w1 >> (nbytes*8 - w2)) != -1)
-			) {
+
+			/* If the value is positive, then check, this is taken
+			 * from rule INT32-C of SEI website.
+			 */
+			if ((w1 >= 0) && (w1 > (i_maxs(nbytes) >> w2)))
+			{
 				trap(EIOVFL);
 			}
+
+			if ((w1 < 0) && (w1 < (i_mins(nbytes) >> w2)))
+			{
+				trap(EIOVFL);
+			}
+
 		}
 	}	
 
diff --git a/util/int/main.c b/util/int/main.c
index 05d49e87f..5587a3112 100644
--- a/util/int/main.c
+++ b/util/int/main.c
@@ -45,15 +45,36 @@ extern void disassemble(void);
 extern void tally(void);
 extern void out_tally(void);
 
+/** Check dynamically that the interpreter can run on the target machine. */
+static void check_requirements(char *name)
+{
+	
+	/* Verify that shift right supported signed shifts. According to ISO C90,
+	 * this is not mandatory, we should not support it here!
+	 */
+	int shrv = -4;
+	if ((shrv >> 1) != -2)
+	{
+		fprintf(stderr,
+			"%s compiled with compiler that does not support signed right shifts. Aborted.",
+			name);
+		exit(1);
+	}
+}
+
 int main(int argc, char *argv[])
 {
 	register int i;
 	register int nosetjmp = 1;
 	int must_disassemble = 0;
 	int must_tally = 0;
-	
+
+
 	prog_name = argv[0];
 
+	check_requirements(prog_name);
+
+
 	/* Initialize the EM machine */
 	PreIgnMask = 0;
 	FRALimit = FRALIMIT;