diff --git a/mach/proto/ncg/codegen.c b/mach/proto/ncg/codegen.c
index c003d8a5d..7e65590ee 100644
--- a/mach/proto/ncg/codegen.c
+++ b/mach/proto/ncg/codegen.c
@@ -1114,7 +1114,6 @@ readcodebytes()
 #ifdef TABLEDEBUG
 initlset(f) char* f;
 {
-	extern char* myalloc();
 
 	set_flag = f;
 	if ((set_fd = open(f + 1, 2)) < 0)
diff --git a/mach/proto/ncg/compute.c b/mach/proto/ncg/compute.c
index 6adc21941..30d129cef 100644
--- a/mach/proto/ncg/compute.c
+++ b/mach/proto/ncg/compute.c
@@ -87,10 +87,8 @@ char opdesc[] = {
 #endif
 };
 
-string salloc(),strcpy(),strcat();
-
-string mycat(s1,s2) register string s1,s2; {
-	register string s;
+static string mycat(string s1, string s2) {
+	string s;
 
 	if (s1==0 || *s1=='\0') return(s2);
 	if (s2==0 || *s2=='\0') return(s1);
@@ -101,7 +99,7 @@ string mycat(s1,s2) register string s1,s2; {
 	return(s);
 }
 
-string mystrcpy(s) register string s; {
+string mystrcpy(string s) {
 	register string r;
 
 	r=salloc(strlen(s));
@@ -109,9 +107,9 @@ string mystrcpy(s) register string s; {
 	return(r);
 }
 
-char digstr[21][15];
+static char digstr[21][15];
 
-string tostring(n) register word n; {
+string tostring(word n) {
 	char buf[25];
 
 	if (n>=-20 && n<=20 && (n&1)==0) {
diff --git a/mach/proto/ncg/equiv.c b/mach/proto/ncg/equiv.c
index 9a18b08bb..9057aa211 100644
--- a/mach/proto/ncg/equiv.c
+++ b/mach/proto/ncg/equiv.c
@@ -21,15 +21,13 @@ static char rcsid[] = "$Id$";
  * Author: Hans van Staveren
  */
 
-extern string myalloc();
+static int rar[MAXCREG];
+static rl_p *lar;
+static int maxindex;
+static int regclass[NREGS];
+static struct perm *perms;
 
-int rar[MAXCREG];
-rl_p *lar;
-int maxindex;
-int regclass[NREGS];
-struct perm *perms;
-
-void permute();
+static void permute(int);
 
 struct perm *
 tuples(regls,nregneeded) rl_p *regls; {
@@ -66,11 +64,10 @@ tuples(regls,nregneeded) rl_p *regls; {
 	return(perms);
 }
 
-void
-permute(index) {
-	register struct perm *pp;
-	register rl_p rlp;
-	register i,j;
+static void permute(int index) {
+	struct perm *pp;
+	rl_p rlp;
+	int i,j;
 
 	if (index == maxindex) {
 		for (pp=perms; pp != 0; pp=pp->p_next) {
diff --git a/mach/proto/ncg/fillem.c b/mach/proto/ncg/fillem.c
index f7f5ffcc9..1306b91fd 100644
--- a/mach/proto/ncg/fillem.c
+++ b/mach/proto/ncg/fillem.c
@@ -55,50 +55,57 @@ Read the documentation.
 #define SEGROM          2
 #define SEGBSS          3
 
-long con();
-
 #define get8()  getc(emfile)
 
-FILE *emfile;
+static FILE *emfile;
 
-int nextispseu,savetab1;
-int opcode;
-int offtyp;
-long argval;
-int dlbval;
-char *str,argstr[128],labstr[128];
-unsigned int maxstrsiz;
-int strsiz;
-int holno=0;
-int procno=0;
-int curseg= -1;
-int part_size=0;
-word part_word=0;
+static int nextispseu,savetab1;
+static int opcode;
+static int offtyp;
+static long argval;
+static int dlbval;
+static char *str,argstr[128],labstr[128];
+static unsigned int maxstrsiz;
+static int strsiz;
+static int holno=0;
+static int procno=0;
+static int curseg= -1;
+static int part_size=0;
+static word part_word=0;
 #ifdef REGVARS
-int regallowed=0;
+static int regallowed=0;
 #endif
 
 extern char em_flag[];
 extern short em_ptyp[];
-extern double atof();
 
+/* machine dependent */
 void prolog(full nlocals);
-void mes();
-void bss();
-void savelab();
-void dumplab();
-void part_flush();
-void xdumplab();
-void switchseg();
+void mes(word);
+
+static int getarg(int);
+static int table1(void);
+static int table2(void);
+static int table3(int);
+static int get16(void);
+static long get32(void);
+static void getstring(void);
+static string strarg(int);
+static void bss(full, int, int);
+static long con(int);
+static void switchseg(int);
+static void savelab(void);
+static void dumplab(void);
+static void xdumplab(void);
+static void part_flush(void);
+static string holstr(word);
 
 /* Own version of atol that continues computing on overflow.
    We don't know that about the ANSI C one.
 */
-long our_atol(s)
-register char *s;
-{
-  register long total = 0;
-  register unsigned digit;
+long our_atol(char *s) {
+  long total = 0;
+  unsigned digit;
   int minus = 0;
 
   while (*s == ' ' || *s == '\t') s++;
@@ -117,14 +124,7 @@ register char *s;
 
 #define sp_cstx sp_cst2
 
-string tostring();
-string holstr();
-string strarg();
-string mystrcpy();
-string myalloc();
-long get32();
-
-in_init(filename) char *filename; {
+void in_init(char *filename) {
 
 	emfile = stdin;
 	if (filename && (emfile=freopen(filename,"r",stdin))==NULL)
@@ -134,19 +134,18 @@ in_init(filename) char *filename; {
 	str = myalloc(maxstrsiz=256);
 }
 
-in_start() {
+void in_start(void) {
 #ifdef modhead
 	fprintf(codefile,"%s",modhead) ;
 #endif
 }
 
-in_finish() {
+static void in_finish(void) {
 }
 
-void
-fillemlines() {
-	register int t,i;
-	register struct emline *lp;
+void fillemlines(void) {
+	int t,i;
+	struct emline *lp;
 
 	while ((emlines+nemlines)-emp<MAXEMLINES-5) {
 		assert(nemlines<MAXEMLINES);
@@ -439,8 +438,8 @@ dopseudo() {
 
 /* ----- input ----- */
 
-int getarg(typset) {
-	register t,argtyp;
+static int getarg(int typset) {
+	int t,argtyp;
 
 	argtyp = t = table2();
 	if (t == EOF)
@@ -452,8 +451,8 @@ int getarg(typset) {
 	return(argtyp);
 }
 
-int table1() {
-	register i;
+static int table1(void) {
+	int i;
 
 	i = get8();
 	if (i < sp_fmnem+sp_nmnem && i >= sp_fmnem) {
@@ -471,8 +470,8 @@ int table1() {
 	return(table3(i));
 }
 
-int table2() {
-	register i;
+static int table2(void) {
+	int i;
 
 	i = get8();
 	if (i < sp_fcst0+sp_ncst0 && i >= sp_fcst0) {
@@ -482,7 +481,7 @@ int table2() {
 	return(table3(i));
 }
 
-int table3(i) {
+static int table3(int i) {
 	word consiz;
 
 	switch(i) {
@@ -525,8 +524,8 @@ int table3(i) {
 	return(i);
 }
 
-int get16() {
-	register int l_byte, h_byte;
+static int get16(void) {
+	int l_byte, h_byte;
 
 	l_byte = get8();
 	h_byte = get8();
@@ -534,9 +533,9 @@ int get16() {
 	return l_byte | (h_byte*256) ;
 }
 
-long get32() {
-	register long l;
-	register int h_byte;
+static long get32(void) {
+	long l;
+	int h_byte;
 
 	l = get8();
 	l |= ((unsigned) get8())*256 ;
@@ -546,9 +545,9 @@ long get32() {
 	return l | (h_byte*256L*256*256L) ;
 }
 
-getstring() {
-	register char *p;
-	register n;
+static void getstring(void) {
+	char *p;
+	int n;
 
 	getarg(cst_ptyp);
 	if (argval < 0)
@@ -565,8 +564,8 @@ getstring() {
 	*p++ = '\0';
 }
 
-char *strarg(t) {
-	register char *p;
+static string strarg(int t) {
+	char *p;
 
 	switch (t) {
 	case sp_ilb1:
@@ -613,9 +612,8 @@ char *strarg(t) {
 	return(mystrcpy(argstr));
 }
 
-void
-bss(n,t,b) full n; {
-	register long s = 0;
+static void bss(full n, int t, int b) {
+	long s = 0;
 
 	if (n % TEM_WSIZE)
 		fatal("bad BSS size");
@@ -637,8 +635,8 @@ bss(n,t,b) full n; {
 		fatal("bad BSS initializer");
 }
 
-long con(t) {
-	register i;
+static long con(int t) {
+	int i;
 
 	strarg(t);
 	switch (t) {
@@ -686,8 +684,7 @@ swtxt() {
 	switchseg(SEGTXT);
 }
 
-void
-switchseg(s) {
+static void switchseg(int s) {
 
 	if (s == curseg)
 		return;
@@ -696,8 +693,7 @@ switchseg(s) {
 		fprintf(codefile,"%s\n",segname[s]);
 }
 
-void
-savelab() {
+static void savelab(void) {
 	register char *p,*q;
 
 	part_flush();
@@ -711,8 +707,7 @@ savelab() {
 		;
 }
 
-void
-dumplab() {
+static void dumplab(void) {
 
 	if (labstr[0] == 0)
 		return;
@@ -721,8 +716,7 @@ dumplab() {
 	labstr[0] = 0;
 }
 
-void
-xdumplab() {
+static void xdumplab(void) {
 
 	if (labstr[0] == 0)
 		return;
@@ -730,8 +724,7 @@ xdumplab() {
 	newdlb(labstr);
 }
 
-void
-part_flush() {
+static void part_flush(void) {
 
 	/*
 	 * Each new data fragment and each data label starts at
@@ -744,7 +737,7 @@ part_flush() {
 	part_word = 0;
 }
 
-string holstr(n) word n; {
+static string holstr(word n) {
 
 	sprintf(str,hol_off,n,holno);
 	return(mystrcpy(str));
diff --git a/mach/proto/ncg/gencode.c b/mach/proto/ncg/gencode.c
index 9cc10778f..d3018b057 100644
--- a/mach/proto/ncg/gencode.c
+++ b/mach/proto/ncg/gencode.c
@@ -22,10 +22,7 @@ static char rcsid[] = "$Id$";
  * Author: Hans van Staveren
  */
 
-string mystrcpy();
-
 FILE *codefile;
-extern FILE *freopen();
 
 out_init(filename) char *filename; {
 
diff --git a/mach/proto/ncg/glosym.c b/mach/proto/ncg/glosym.c
index 4052c1bfe..fa88895af 100644
--- a/mach/proto/ncg/glosym.c
+++ b/mach/proto/ncg/glosym.c
@@ -16,9 +16,7 @@ static char rcsid[] = "$Id$";
  * Author: Hans van Staveren
  */
 
-extern string myalloc();
-
-glosym_p glolist= (glosym_p) 0;
+static glosym_p glolist= (glosym_p) 0;
 
 enterglo(name,romp) string name; word *romp; {
 	register glosym_p gp;
diff --git a/mach/proto/ncg/label.c b/mach/proto/ncg/label.c
index 0c192589c..ed88a8dc7 100644
--- a/mach/proto/ncg/label.c
+++ b/mach/proto/ncg/label.c
@@ -5,7 +5,6 @@
 #include "label.h"
 
 static label_p label_list = (label_p)0;
-extern char *myalloc();
 
 void
 add_label(num, height, flth)
diff --git a/mach/proto/ncg/main.c b/mach/proto/ncg/main.c
index 7f214f349..096b470f2 100644
--- a/mach/proto/ncg/main.c
+++ b/mach/proto/ncg/main.c
@@ -22,6 +22,10 @@ int Debug=0;
 char *strtdebug="";
 #endif
 
+/* fillem.c */
+void in_init(char *);
+void in_start(void);
+
 main(argc,argv) char **argv; {
 	register unsigned n;
 	extern unsigned cc1,cc2,cc3,cc4;
diff --git a/mach/proto/ncg/nextem.c b/mach/proto/ncg/nextem.c
index 0e8446b3f..daad8223c 100644
--- a/mach/proto/ncg/nextem.c
+++ b/mach/proto/ncg/nextem.c
@@ -27,6 +27,9 @@ static char rcsid[] = "$Id$";
 extern char em_mnem[][4];
 #endif
 
+/* fillem.c */
+void fillemlines(void);
+
 byte *trypat(bp,len) register byte *bp; {
 	register patlen,i;
 	result_t result;
diff --git a/mach/proto/ncg/regvar.c b/mach/proto/ncg/regvar.c
index b863bffd5..2c2650086 100644
--- a/mach/proto/ncg/regvar.c
+++ b/mach/proto/ncg/regvar.c
@@ -24,8 +24,7 @@ static char rcsid[] = "$Id$";
  *
  * Author: Hans van Staveren
  */
-extern string myalloc();
-struct regvar *rvlist;
+static struct regvar *rvlist;
 
 struct regvar *
 linkreg(long of, int sz, int tp, int sc) {
diff --git a/mach/proto/ncg/regvar.h b/mach/proto/ncg/regvar.h
index 089bd72b1..2f3bfecd0 100644
--- a/mach/proto/ncg/regvar.h
+++ b/mach/proto/ncg/regvar.h
@@ -18,7 +18,6 @@ struct regassigned {
 	int		ra_score;
 };
 
-extern struct regvar *rvlist;
 extern int nregvar[];
 extern struct regassigned *regassigned[];
 
diff --git a/mach/proto/ncg/salloc.c b/mach/proto/ncg/salloc.c
index a261a5a09..7a7dd189c 100644
--- a/mach/proto/ncg/salloc.c
+++ b/mach/proto/ncg/salloc.c
@@ -32,7 +32,7 @@ static char rcsid[] = "$Id$";
 char *stab[MAXSTAB];
 int nstab=0;
 
-void chkstr();
+static void chkstr(string, char *);
 
 string myalloc(size) {
 	register string p;
@@ -43,21 +43,21 @@ string myalloc(size) {
 	return(p);
 }
 
-myfree(p) string p; {
+void myfree(string p) {
 
 	free(p);
 }
 
-popstr(nnstab) {
-	register i;
+void popstr(int nnstab) {
+	int i;
 
 	for (i=nnstab;i<nstab;i++)
 		myfree(stab[i]);
 	nstab = nnstab;
 }
 
-char *salloc(size) {
-	register char *p;
+char *salloc(int size) {
+	char *p;
 
 	if (nstab==MAXSTAB)
 		fatal("String table overflow");
@@ -66,7 +66,7 @@ char *salloc(size) {
 	return(p);
 }
 
-compar(p1,p2) char **p1,**p2; {
+static int compar(char **p1, char **p2) {
 
 	assert(*p1 != *p2);
 	if (*p1 < *p2)
@@ -74,14 +74,13 @@ compar(p1,p2) char **p1,**p2; {
 	return(1);
 }
 
-void
-garbage_collect() {
-	register i;
+void garbage_collect(void) {
+	int i;
 	struct emline *emlp;
 	token_p tp;
 	tkdef_p tdp;
 	struct reginfo *rp;
-	register char **fillp,**scanp;
+	char **fillp,**scanp;
 	char used[MAXSTAB];     /* could be bitarray */
 
 	if (nstab<THRESHOLD)
@@ -119,9 +118,9 @@ garbage_collect() {
 	nstab = fillp-stab;
 }
 
-void
-chkstr(str,used) string str; char used[]; {
-	register low,middle,high;
+static void
+chkstr(string str, char *used) {
+	int low,middle,high;
 
 	low=0; high=nstab-1;
 	while (high>low) {
diff --git a/mach/proto/ncg/subr.c b/mach/proto/ncg/subr.c
index 6e57ed18d..08861274d 100644
--- a/mach/proto/ncg/subr.c
+++ b/mach/proto/ncg/subr.c
@@ -24,7 +24,6 @@ static char rcsid[] = "$Id$";
  * Author: Hans van Staveren
  */
 
-string myalloc();
 unsigned codegen();
 
 match(tp,tep,optexp) register token_p tp; register set_p tep; {
diff --git a/mach/proto/ncg/types.h b/mach/proto/ncg/types.h
index 50fc1aecd..91625557d 100644
--- a/mach/proto/ncg/types.h
+++ b/mach/proto/ncg/types.h
@@ -28,3 +28,13 @@ typedef char * string;
 #ifndef WRD_FMT
 #define WRD_FMT "%ld"
 #endif /* WRD_FMT */
+
+/* compute.c */
+string mystrcpy(string);
+string tostring(word);
+/* salloc.c */
+string myalloc(int);
+void myfree(string);
+void popstr(int);
+char *salloc(int);
+void garbage_collect(void);