Index: libcio/atoi.c
===================================================================
--- libcio/atoi.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/atoi.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,7 +9,5 @@
 #include "ctype.h"
 
-int
-atoi(cp)
-register char *cp;
+int atoi(char *cp)
 {
 	register unsigned i;
Index: libcio/atol.c
===================================================================
--- libcio/atol.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/atol.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,7 +9,5 @@
 #include "ctype.h"
 
-long
-atol(cp)
-register char *cp;
+long atol(char *cp)
 {
 	register long n;
Index: libcio/blkrd.c
===================================================================
--- libcio/blkrd.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/blkrd.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -40,5 +40,5 @@
 #endif
 
-extern	int	_nsic();		/* next sector function */
+extern	int	_nsic(struct fcb *fcp, struct bpb *bpp, char *fp);
 
 extern	long	_berrno;		/* last file system bios error number */
@@ -73,8 +73,5 @@
 */
 
-long
-_secrd(buf, rec)
-register char *buf;
-register short rec;
+long _secrd(char *buf, short rec)
 {
 	register short	track, side, sector;
@@ -138,9 +135,5 @@
 */
 
-int
-blkrd(fcp, buf, ns)
-register struct fcb *fcp;
-register char *buf;
-register int ns;
+int blkrd(struct fcb *fcp, char *buf, int ns)
 {
 	register long	brc;		/* bios return code */
Index: libcio/blkwr.c
===================================================================
--- libcio/blkwr.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/blkwr.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -24,5 +24,7 @@
 #include "fspars.h"
 
-extern	int	_nsic(), _alcnew(), _newcls();
+extern	int	_nsic(struct fcb *fcp, struct bpb *bpp, char *fp);
+extern	int	_alcnew(struct fcb *fcp);
+extern	int	_newcls(void);
 
 extern	long	_berrno;		/* last file system bios error number */
@@ -63,8 +65,5 @@
 */
 
-long
-_secwr(buf, rec)
-register char *buf;
-register short rec;
+long _secwr(char *buf, short rec)
 {
 	register short	track, side, sector;
@@ -125,9 +124,5 @@
 */
 
-int
-blkwr(fcp, buf, ns)
-struct fcb *fcp;
-char *buf;
-int ns;
+int blkwr(struct fcb *fcp, char *buf, int ns)
 {
 	long	rc;
Index: libcio/close.c
===================================================================
--- libcio/close.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/close.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -12,5 +12,7 @@
 #include "stddefs.h"
 
-extern	int	_badfd(), ClsFile(), _clsvol();
+extern	int	_badfd(void);
+extern	int	ClsFile(struct fcb *fcp);
+extern	void	_clsvol(void);
 
 extern	int	_fatmod, _dirmod;
@@ -29,5 +31,5 @@
 */
 
-_clsfat()
+void _clsfat(void)
 {
 	/* write the primary FAT to disk */
@@ -50,5 +52,5 @@
 */
 
-_clsdir()
+void _clsdir(void)
 {
 	/* write the directory to disk */
@@ -70,7 +72,5 @@
 */
 
-int
-close(fd)
-int fd;
+int close(int fd)
 {
 	register struct channel *chp;
@@ -112,7 +112,5 @@
 */
 
-int
-_filecl(fp)
-register struct fcb *fp;
+int _filecl(struct fcb *fp)
 {
 	register int rc;
@@ -129,5 +127,5 @@
 */
 
-_fd_cls()
+void _fd_cls(void)
 {
 	register int fd;
Index: libcio/clusmap.c
===================================================================
--- libcio/clusmap.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/clusmap.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -12,11 +12,13 @@
 #include "stddefs.h"
 
-extern	int	micons(), _gtcl12();
-extern	long	miconl();
+extern	short	micons(short wi);
+extern	unsigned	_gtcl12(char *fat, unsigned cl);
+extern	long	miconl(long wi);
 
 extern	struct	bpb	*_thebpb;
 extern	short	_thefat[];
 
-extern	int	_filecl(), _noper();
+extern	int	_filecl(struct fcb *fp);
+extern	int	_noper(void);
 
 /* 
@@ -79,6 +81,5 @@
 */
 
-static int
-waitcr()
+static int waitcr(void)
 {
 	char	c;
@@ -103,7 +104,5 @@
 */
 
-int
-ClusMap(fcp)
-struct fcb *fcp;
+int ClusMap(struct fcb *fcp)
 {
 	int	clus, nc;
@@ -172,7 +171,5 @@
 */
 
-struct fcb *
-FCBmode(fcp)
-register struct fcb *fcp;
+struct fcb *FCBmode(struct fcb *fcp)
 {
 	register unsigned short mf;
@@ -217,7 +214,5 @@
 */
 
-struct fcb *
-SnapFCB(fcp)
-register struct fcb *fcp;
+struct fcb *SnapFCB(struct fcb *fcp)
 {
 	printf("\nFCB at 0x%08lx:  [%-8.8s].[%-3.3s]\n",
@@ -257,7 +252,5 @@
 */
 
-MapFAT(fat, ncl, stops)
-register char *fat;
-short ncl, stops;
+void MapFAT(char *fat, short ncl, short stops)
 {
 	register int i;
@@ -293,7 +286,5 @@
 */
 
-FILE *
-FILEfl(fp)
-FILE *fp;
+FILE *FILEfl(FILE *fp)
 {
 	register unsigned short mf;
@@ -325,6 +316,5 @@
 */
 
-FILEpr(fp)
-FILE *fp;
+void FILEpr(FILE *fp)
 {
 	int	(*arg)(), ft;
@@ -387,7 +377,5 @@
 */
 
-struct fcb *
-fd2fcb(fd)
-short fd;
+struct fcb *fd2fcb(short fd)
 {
 	if ((fd < 0) OR (fd > MAXCHAN))
@@ -403,7 +391,5 @@
 */
 
-struct fcb *
-fp2fcb(fp)
-FILE *fp;
+struct fcb *fp2fcb(FILE *fp)
 {
 	if (fp EQ (FILE *)NULL)
Index: libcio/conin.c
===================================================================
--- libcio/conin.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/conin.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -14,14 +14,12 @@
 #include "stddefs.h"
 
-extern	char	*memcpy();
-extern	int	readbuf(), writeln();
+extern	char	*memcpy(char *s1, char *s2, int n);
+extern	int	readbuf(int dev, char *buf);
+extern	void	writeln(int unit, char *buf);
 
 char _ConBuf[258];	/* console input buffer */
 int _CBused;
 
-int
-_conin(x, buff, len)
-char *buff;
-int len;
+int _conin(char *buff, int len)
 {
 	int 	nbp;
Index: libcio/conwr.c
===================================================================
--- libcio/conwr.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/conwr.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -19,9 +19,5 @@
    ============================================================================
 */
-int
-_conwr(kind, buff, len)
-int kind;
-register char *buff;
-int len;
+int _conwr(int kind, char *buff, int len)
 {
 	register int count;
Index: libcio/dirfns.c
===================================================================
--- libcio/dirfns.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/dirfns.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,5 +9,5 @@
 #include "biosdefs.h"
 
-extern	int	sprintf();
+extern	long	sprintf(char *str, char *fmt, ...);
 
 static char atrcons[] = "ADVSHR";
@@ -19,8 +19,5 @@
 */
 
-char *
-atrstr(atr, s)
-register short atr;
-register char s[];
+char *atrstr(short atr, char s[])
 {
 	register short	i, j;
@@ -68,7 +65,5 @@
 */
 
-char *
-mname(n)
-short n;
+char *mname(short n)
 {
 	return((n < 1 || n > 12) ? mnames[0] : mnames[n]);
@@ -86,8 +81,5 @@
 */
 
-char *
-dtunpk(din, tin, s, fmt)
-short din, tin, fmt;
-char *s;
+char *dtunpk(short din, short tin, short fmt, char *s)
 {
 	register short	ftm, fdt;
Index: libcio/fgets.c
===================================================================
--- libcio/fgets.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fgets.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,7 +11,5 @@
 #define	EATCHAR	'\n'	/* character to be "eaten" on input */
 
-int
-agetc(ptr)
-register FILE *ptr;
+int agetc(FILE *ptr)
 {
 	register int c;
@@ -35,7 +33,5 @@
 }
 
-char *
-gets(line)
-char *line;
+char *gets(char *line)
 {
 	register char *cp;
@@ -55,9 +51,5 @@
 }
 
-char *
-fgets(s, n, fp)
-char *s;
-int n;
-FILE *fp;
+char *fgets(char *s, int n, FILE *fp)
 {
 	register int c;
Index: libcio/filesys.c
===================================================================
--- libcio/filesys.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/filesys.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -29,8 +29,9 @@
 #define	DE_NULL		((struct dirent *)0L)
 
-extern	unsigned micons();
-extern	long	miconl();
-extern	int	_ptcl12();
-extern	char	*FilName(), *FilExt();
+extern	short	micons(short wi);
+extern	long	miconl(long wi);
+extern	void	_ptcl12(unsigned *fat, unsigned cl, unsigned val);
+extern	char	*FilName(char *s, char *p);
+extern	char	*FilExt(char *s, char *p);
 
 #if DEBUGIT
@@ -65,8 +66,5 @@
 */
 
-unsigned
-_cl2lsn(bpp, clnum)
-struct bpb *bpp;
-unsigned clnum;
+unsigned _cl2lsn(struct bpb *bpp, unsigned clnum)
 {
 	return(bpp->datrec + (bpp->clsiz * (clnum - 2)) );
@@ -80,8 +78,5 @@
 */
 
-unsigned
-_gtcl12(fat, cl)
-register char *fat;
-unsigned cl;
+unsigned _gtcl12(char *fat, unsigned cl)
 {
 	register unsigned cla, clt;
@@ -109,8 +104,5 @@
 */
 
-unsigned
-_getfat(bufad, bpp, nfat)
-unsigned *bufad, nfat;
-register struct bpb *bpp;
+unsigned _getfat(unsigned *bufad, unsigned nfat, struct bpb *bpp)
 {
 	unsigned fatsec;
@@ -131,8 +123,5 @@
 */
 
-int
-_rdfat(bufad, bpp)
-unsigned *bufad;
-struct bpb *bpp;
+int _rdfat(unsigned *bufad, struct bpb *bpp)
 {
 	if (_getfat(bufad, bpp, 0)) {
@@ -154,8 +143,5 @@
 */
 
-int
-_rdroot(buf, bpp)
-unsigned *buf;
-register struct bpb *bpp;
+int _rdroot(unsigned *buf, struct bpb *bpp)
 {
 	return(BIOS(B_RDWR, 0, (char *)buf, bpp->rdlen,
@@ -176,9 +162,5 @@
 */
 
-int
-_nsic(fcp, bpp, fp)
-register struct fcb *fcp;
-struct bpb *bpp;
-char *fp;
+int _nsic(struct fcb *fcp, struct bpb *bpp, char *fp)
 {
 	register unsigned tfe;
@@ -277,7 +259,5 @@
 */
 
-struct dirent *
-_dsrch(de)
-register struct dirent *de;
+struct dirent *_dsrch(struct dirent *de)
 {
 	unsigned i, dl;
@@ -316,6 +296,5 @@
 */
 
-struct dirent *
-_dsnew()
+struct dirent *_dsnew(void)
 {
 	unsigned i, dl;
@@ -353,7 +332,5 @@
 */
 
-_deadio(fcp, err)
-register struct fcb *fcp;
-int err;
+void _deadio(struct fcb *fcp, int err)
 {
 	fcp->clsec = 0;
@@ -378,7 +355,5 @@
 */
 
-int
-_seek(fcp)
-register struct fcb *fcp;
+int _seek(struct fcb *fcp)
 {
 	register unsigned acls, rcls, nc;
@@ -486,7 +461,5 @@
 */
 
-int
-_ftrnc(dp)
-struct dirent *dp;
+int _ftrnc(struct dirent *dp)
 {
 	register unsigned acls, ncls;
@@ -552,6 +525,5 @@
 */
 
-int
-_newcls()
+int _newcls(void)
 {
 	register int tc, i;
@@ -576,7 +548,5 @@
 */
 
-int
-_alcnew(fcp)
-register struct fcb *fcp;
+int _alcnew(struct fcb *fcp)
 {
 	register int ac, nc, pc;
@@ -669,7 +639,5 @@
 */
 
-int
-_fmake(fcp)
-struct fcb *fcp;
+int _fmake(struct fcb *fcp)
 {
 	register struct dirent *dp;
@@ -696,6 +664,5 @@
 */
 
-int
-_opnvol()
+int _opnvol(void)
 {
 	register long drc;
@@ -783,7 +750,5 @@
 */
 
-int
-_opfcb(fcp)
-register struct fcb *fcp;
+int _opfcb(struct fcb *fcp)
 {
 	int	rc;
@@ -927,9 +892,5 @@
 */
 
-int
-_inifcb(fcp, name, ext, mode)
-register struct fcb *fcp;
-char *name, *ext;
-int mode;
+int _inifcb(struct fcb *fcp, char *name, char *ext, int mode)
 {
 	int	fl;
@@ -1063,7 +1024,5 @@
 */
 
-int
-ClsFile(fcp)
-register struct fcb *fcp;
+int ClsFile(struct fcb *fcp)
 {
 	register struct dirent *dp;
@@ -1144,5 +1103,5 @@
 */
 
-_clsvol()
+void _clsvol(void)
 {
 	if (_fatmod) {
@@ -1177,8 +1136,5 @@
 */
 
-short
-fcbinit(name, fcp)
-register char *name;
-register struct fcb *fcp;
+short fcbinit(char *name, struct fcb *fcp)
 {
 	char	tmpname[9], tmpext[4];
@@ -1197,7 +1153,5 @@
 */
 
-int
-DelFile(fcp)
-struct fcb *fcp;
+int DelFile(struct fcb *fcp)
 {
 #if	DEBUGIT
Index: libcio/filname.c
===================================================================
--- libcio/filname.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/filname.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -20,7 +20,5 @@
 */
 
-char *
-FilName(s, p)
-register char *s, *p;
+char *FilName(char *s, char *p)
 {
 	register char	*tp;
@@ -61,7 +59,5 @@
 */
 
-char *
-FilExt(s, p)
-register char *s, *p;
+char *FilExt(char *s, char *p)
 {
 	register char c, *tp;
Index: libcio/flread.c
===================================================================
--- libcio/flread.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/flread.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -19,9 +19,5 @@
 */
 
-int
-flread(buff, len, fp)
-register char *buff;
-register long len;
-FILE *fp;
+int flread(char *buff, long len, FILE *fp)
 {
 	register int	ilen;
Index: libcio/fopen.c
===================================================================
--- libcio/fopen.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fopen.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,10 +11,7 @@
 #include "stddefs.h"
 
-extern	long lseek();
+extern	long	lseek(int fd, long pos, int how);
 
-FILE *
-_opener(name, mode, aflag)
-char *name, *mode;
-int aflag;
+FILE *_opener(char *name, char *mode, int aflag)
 {
 	register FILE *fp;
@@ -73,21 +70,15 @@
 */
 
-FILE *
-fopen(name, mode)
-char *name, *mode;
+FILE *fopen(char *name, char *mode)
 {
 	return(_opener(name, mode, 0));
 }
 
-FILE *
-fopena(name, mode)
-char *name, *mode;
+FILE *fopena(char *name, char *mode)
 {
 	return(_opener(name, mode, 0));
 }
 
-FILE *
-fopenb(name, mode)
-char *name, *mode;
+FILE *fopenb(char *name, char *mode)
 {
 	return(_opener(name, mode, O_RAW));
Index: libcio/fprintf.c
===================================================================
--- libcio/fprintf.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fprintf.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -12,8 +12,8 @@
 static FILE *Stream;
 
-extern	int	dofmt_();
-extern	int	aputc();
+extern	long	dofmt_(int (*putsub)(), char *format, va_list args);
+extern	int	aputc(int c, FILE *ptr);
 
-static	int	fpsub();
+	static int fpsub(int c);
 
 int fprintf(FILE *stream, char *fmt, ...)
@@ -29,8 +29,5 @@
 }
 
-static
-int
-fpsub(c)
-int c;
+static int fpsub(int c)
 {
 	return(aputc(c, Stream));
Index: libcio/fputs.c
===================================================================
--- libcio/fputs.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fputs.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,7 +9,5 @@
 #include "stddefs.h"
 
-int
-puts(str)
-register char *str;
+int puts(char *str)
 {
 	while (*str)
@@ -20,8 +18,5 @@
 }
 
-int
-aputc(c,ptr)
-register int c;
-register FILE *ptr;
+int aputc(int c, FILE *ptr)
 {
 	c &= 127;
@@ -34,8 +29,5 @@
 }
 
-int
-fputs(s,fp)
-register char *s;
-FILE *fp;
+int fputs(char *s, FILE *fp)
 {
 	while ( *s )
Index: libcio/fread.c
===================================================================
--- libcio/fread.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fread.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -16,10 +16,5 @@
 */
 
-int
-fread(buffer, size, number, stream)
-register char *buffer;
-unsigned size;
-int number;
-FILE *stream;
+int fread(char *buffer, unsigned size, int number, FILE *stream)
 {
 	int total;
Index: libcio/fscanf.c
===================================================================
--- libcio/fscanf.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fscanf.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -12,7 +12,5 @@
 static FILE *scnfp;
 
-static
-int
-gchar(what)
+static int gchar(what)
 {
 	if (what EQ 0) {
@@ -28,8 +26,5 @@
 }
 
-int
-scanf(fmt, args)
-char *fmt;
-int *args;
+int scanf(char *fmt, int *args)
 {
 	scnfp = stdin;
@@ -38,9 +33,5 @@
 }
 
-int
-fscanf(fp, fmt, args)
-FILE *fp;
-char *fmt;
-int *args;
+int fscanf(FILE *fp, char *fmt, int *args)
 {
 	scnfp = fp;
Index: libcio/fseek.c
===================================================================
--- libcio/fseek.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fseek.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,5 +11,5 @@
 #include "stddefs.h"
 
-extern	long	lseek();
+extern	long	lseek(int fd, long pos, int how);
 
 /*
@@ -19,8 +19,5 @@
 */
 
-fseek(fp, pos, mode)
-register FILE *fp;
-long pos;
-int mode;
+int fseek(FILE *fp, long pos, int mode)
 {
 	register int i, lr;
Index: libcio/fsinit.c
===================================================================
--- libcio/fsinit.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fsinit.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -16,5 +16,6 @@
 extern	int	_bpbin, _dirin, _fatin, _dirmod, _fatmod;
 
-int	_badfd(), _noper();
+int	_badfd(void);
+int	_noper(void);
 
 char	*Stdbufs;			/* buffer chain pointer */
@@ -53,6 +54,5 @@
 */
 
-int
-_badfd()
+int _badfd(void)
 {
 	errno = EBADF;		/* set bad fd code */
@@ -66,6 +66,5 @@
 */
 
-int
-_noper()
+int _noper(void)
 {
 	return(SUCCESS);	/* return with a non-error indication */
@@ -82,9 +81,5 @@
 */
 
-InitCH(cp, rdi, wri, ioi, ski, cfp, charg)
-register struct channel *cp;
-char rdi, wri, ioi, ski;
-int (*cfp)();
-io_arg charg;
+void InitCH(struct channel *cp, char rdi, char wri, char ioi, char ski, int (*cfp)(), io_arg charg)
 {
 	cp->c_read  = rdi;
@@ -102,9 +97,5 @@
 */
 
-Init_CB(fp, flags, unit, bufad, bufsize)
-register FILE *fp;
-char unit, flags;
-long *bufad;
-int bufsize;
+void Init_CB(FILE *fp, char unit, char flags, long *bufad, int bufsize)
 {
 	fp->_bp     = (char *)0L;
@@ -127,5 +118,5 @@
 */
 
-InitFS()
+void InitFS(void)
 {
 	register int i;
Index: libcio/fsize.c
===================================================================
--- libcio/fsize.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fsize.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,5 +11,7 @@
 #include "stddefs.h"
 
-extern	short	_gtcl12(), _opnvol(), _filecl();
+extern	unsigned	_gtcl12(char *fat, unsigned cl);
+extern	int	_opnvol(void);
+extern	int	_filecl(struct fcb *fp);
 
 extern	unsigned _thefat[];
@@ -25,8 +27,5 @@
 */
 
-long
-fsize(fp, how)
-FILE *fp;
-short how;
+long fsize(FILE *fp, short how)
 {
 	register struct channel *chp;
@@ -71,7 +70,5 @@
 */
 
-short
-dspace(which)
-short which;
+short dspace(short which)
 {
 	register short maxcl, clcount, nc;
Index: libcio/fstubs.c
===================================================================
--- libcio/fstubs.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fstubs.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -40,8 +40,5 @@
 */
 
-int
-readbuf(dev, buf)
-int dev;
-char *buf;
+int readbuf(int dev, char *buf)
 {
 	xtrap15();
Index: libcio/ftell.c
===================================================================
--- libcio/ftell.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/ftell.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -17,5 +17,5 @@
 #endif
 
-extern	int	_filecl();
+extern	int	_filecl(struct fcb *fp);
 
 /*
@@ -25,7 +25,5 @@
 */
 
-long
-ftell(fp)
-register FILE *fp;
+long ftell(FILE *fp)
 {
 	register struct fcb *fcp;
Index: libcio/fwrite.c
===================================================================
--- libcio/fwrite.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/fwrite.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -20,9 +20,5 @@
 */
 
-int
-fwrite(buffer, size, number, stream)
-register char *buffer;
-register int size, number;
-register FILE *stream;
+int fwrite(char *buffer, int size, int number, FILE *stream)
 {
 	register int i, j;
Index: libcio/getbuff.c
===================================================================
--- libcio/getbuff.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/getbuff.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,6 +9,5 @@
 #include "stddefs.h"
 
-getbuff(ptr)
-register FILE *ptr;
+void getbuff(FILE *ptr)
 {
 	char *buffer;
Index: libcio/getc.c
===================================================================
--- libcio/getc.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/getc.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,7 +9,5 @@
 #include "stddefs.h"
 
-int
-getc(ptr)
-register FILE *ptr;
+int getc(FILE *ptr)
 {
 	register int len;
Index: libcio/getl.c
===================================================================
--- libcio/getl.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/getl.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -8,5 +8,5 @@
 #include "stdio.h"
 
-extern	int	fgetc();
+extern	int	getc(FILE *ptr);
 
 /*
@@ -19,7 +19,5 @@
 */
 
-long
-getl(stream)
-register FILE *stream;
+long getl(FILE *stream)
 {
 	long temp;
Index: libcio/getw.c
===================================================================
--- libcio/getw.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/getw.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -8,5 +8,5 @@
 #include "stdio.h"
 
-extern	int	fgetc();
+extern	int	getc(FILE *ptr);
 
 /*
@@ -19,7 +19,5 @@
 */
 
-int
-getw(stream)
-register FILE *stream;
+int getw(FILE *stream)
 {
 	int temp;
Index: libcio/lseek.c
===================================================================
--- libcio/lseek.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/lseek.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -13,5 +13,5 @@
 #include "stddefs.h"
 
-extern	int	_seek();
+extern	int	_seek(struct fcb *fcp);
 
 #if	DEBUGIT
@@ -19,9 +19,5 @@
 #endif
 
-long
-lseek(fd, pos, how)
-int fd;
-register long pos;
-int how;
+long lseek(int fd, long pos, int how)
 {
 	register struct fcb *fp;
Index: libcio/open.c
===================================================================
--- libcio/open.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/open.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -12,10 +12,14 @@
 #include "stddefs.h"
 
-extern	int	_badfd(), _noper();
-extern	int	_inifcb(), _opfcb();
-
-extern	char	*FilName(), *FilExt();
-
-int	_fileop(), _filecl();
+extern	int	_badfd(void);
+extern	int	_noper(void);
+extern	int	_inifcb(struct fcb *fcp, char *name, char *ext, int mode);
+extern	int	_opfcb(struct fcb *fcp);
+
+extern	char	*FilName(char *s, char *p);
+extern	char	*FilExt(char *s, char *p);
+
+int	_fileop(char *name, int flag, int mode, struct channel *chp, struct devtabl *dp);
+int	_filecl(struct fcb *fp);
 
 static struct device condev  = { 2, 2, 1, 0, _noper  };
@@ -51,8 +55,5 @@
 */
 
-int
-open(name, flag, mode)
-char *name;
-int flag, mode;
+int open(char *name, int flag, int mode)
 {
 	register struct devtabl	*dp;
@@ -130,8 +131,5 @@
 */
 
-int
-opena(name, flag, mode)
-char *name;
-int flag, mode;
+int opena(char *name, int flag, int mode)
 {
 	return(open(name, flag, mode));
@@ -147,8 +145,5 @@
 */
 
-int
-openb(name, flag, mode)
-char *name;
-int flag, mode;
+int openb(char *name, int flag, int mode)
 {
 	return(open(name, flag|O_RAW, mode));
@@ -169,8 +164,5 @@
 */
 
-int
-creat(name, mode)
-char *name;
-int mode;
+int creat(char *name, int mode)
 {
 	return(open(name, O_WRONLY|O_TRUNC|O_CREAT, mode));
@@ -191,8 +183,5 @@
 */
 
-int
-creata(name, mode)
-char *name;
-int mode;
+int creata(char *name, int mode)
 {
 	return(open(name, O_WRONLY|O_TRUNC|O_CREAT, mode));
@@ -209,8 +198,5 @@
 */
 
-int
-creatb(name, mode)
-char *name;
-int mode;
+int creatb(char *name, int mode)
 {
 	return(open(name, O_WRONLY|O_TRUNC|O_CREAT|O_RAW, mode));
@@ -229,10 +215,5 @@
 */
 
-int
-_fileop(name, flag, mode, chp, dp)
-char *name;
-int flag, mode;
-struct channel *chp;
-struct devtabl *dp;
+int _fileop(char *name, int flag, int mode, struct channel *chp, struct devtabl *dp)
 {
 	register struct fcb *fp;
Index: libcio/posit.c
===================================================================
--- libcio/posit.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/posit.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,5 +11,5 @@
 #include "stddefs.h"
 
-extern	int	_seek();
+extern	int	_seek(struct fcb *fcp);
 
 /*
@@ -19,8 +19,5 @@
 */
 
-int
-posit(fd, pos)
-int fd;
-unsigned pos;
+int posit(int fd, unsigned pos)
 {
 	register struct fcb *fp;
Index: libcio/putc.c
===================================================================
--- libcio/putc.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/putc.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,5 +9,7 @@
 #include "stddefs.h"
 
-extern	int	write(), getbuff(), close();
+extern	int	write(int fd, char *buff, unsigned len);
+extern	void	getbuff(FILE *ptr);
+extern	int	close(int fd);
 
 extern int (*_clsall)();
@@ -17,5 +19,5 @@
 int	_ClFlag;
 
-int	fclose();
+int	fclose(FILE *ptr);
 
 /*
@@ -25,6 +27,5 @@
 */
 
-static
-closall()
+static void closall(void)
 {
 	register FILE *fp;
@@ -46,8 +47,5 @@
 */
 
-int
-flush_(ptr, data)
-register FILE *ptr;
-int data;
+int flush_(FILE *ptr, int data)
 {
 	register int size;
@@ -107,7 +105,5 @@
 */
 
-int
-fflush(ptr)
-FILE *ptr;
+int fflush(FILE *ptr)
 {
 	return(flush_(ptr, -1));
@@ -120,7 +116,5 @@
 */
 
-int
-fclose(ptr)
-register FILE *ptr;
+int fclose(FILE *ptr)
 {
 	int err;
@@ -156,8 +150,5 @@
 */
 
-int
-putc(c, ptr)
-int c;
-register FILE *ptr;
+int putc(int c, FILE *ptr)
 {
 	if (ptr->_bp GE ptr->_bend)
@@ -173,6 +164,5 @@
 */
 
-int
-puterr(c)
+int puterr(c)
 {
 	return(putc(c, stderr));
Index: libcio/putl.c
===================================================================
--- libcio/putl.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/putl.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,7 +11,5 @@
 #include "stddefs.h"
 
-putl(w, stream)
-register long w;
-register FILE *stream;
+void putl(long w, FILE *stream)
 {
 	if (putc(((w >> 24) & 0xFF), stream) < 0 ) 
Index: libcio/putw.c
===================================================================
--- libcio/putw.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/putw.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -11,7 +11,5 @@
 #include "stddefs.h"
 
-putw(w, stream)
-register unsigned w;
-FILE *stream;
+void putw(unsigned w, FILE *stream)
 {
 	if (putc(((w >> 8) & 0xFF), stream) < 0 ) 
Index: libcio/read.c
===================================================================
--- libcio/read.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/read.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -46,9 +46,11 @@
 #endif
 
-extern	int	_badfd(), _conin(), _seek();
+extern	int	_badfd(void);
+extern	int	_conin(char *buff, int len);
+extern	int	_seek(struct fcb *fcp);
 
-extern	char	*memcpy();
+extern	char	*memcpy(char *s1, char *s2, int n);
 
-int	_filerd();
+int	_filerd(struct fcb *fp, char *buffer, unsigned len);
 
 static int (*t_read[])() = {
@@ -70,9 +72,5 @@
 */
 
-int
-read(fd, buff, len)
-int fd;
-char *buff;
-unsigned len;
+int read(int fd, char *buff, unsigned len)
 {
 	register struct channel *chp;
@@ -99,9 +97,5 @@
 */
 
-int
-_getsec(fp, buf, len)
-register struct fcb *fp;
-char *buf;
-unsigned len;
+int _getsec(struct fcb *fp, char *buf, unsigned len)
 {
 	if ((errno = ReadRN(fp, Wrkbuf)) NE 0)	/* get current sector */
@@ -132,9 +126,5 @@
 */
 
-int
-_filerd(fp, buffer, len)
-register struct fcb *fp;
-char *buffer;
-unsigned len;
+int _filerd(struct fcb *fp, char *buffer, unsigned len)
 {
 	register unsigned l;
Index: libcio/readrn.c
===================================================================
--- libcio/readrn.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/readrn.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -27,9 +27,9 @@
 
 #if	TBUFFER
-extern	long	_secrd();
+extern	long	_secrd(char *buf, short rec);
 #endif
 
 extern	long	_berrno;
-extern	int	_seek();
+extern	int	_seek(struct fcb *fcp);
 
 /* 
@@ -44,8 +44,5 @@
 */
 
-int
-ReadRN(fcp, buf)
-struct fcb *fcp;
-char *buf;
+int ReadRN(struct fcb *fcp, char *buf)
 {
 	int	sv;		/* seek return code */
Index: libcio/rename.c
===================================================================
--- libcio/rename.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/rename.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -6,6 +6,5 @@
 */
 
-rename(old, new)
-char *old, *new;
+int rename(char *old, char *new)
 {
 	char buff[60];
Index: libcio/scan.c
===================================================================
--- libcio/scan.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/scan.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -13,5 +13,5 @@
 static int (*gsub)();
 
-extern char *index();
+extern char *index(char *str, char c);
 
 static char *scnstr;
@@ -22,10 +22,5 @@
 */
 
-static
-long
-getnum(list, values, base)
-char *list;
-char *values;
-int base;
+static long getnum(char *list, char *values, int base)
 {
 	register long val;
@@ -71,6 +66,5 @@
 */
 
-static
-skipblk()
+static int skipblk(void)
 {
 	while (isspace((*gsub)(0)))
@@ -83,6 +77,5 @@
 }
 
-static
-sgetc(what)
+static int sgetc(what)
 {
 	if (what EQ 0) {
@@ -106,8 +99,5 @@
 */
 
-scanfmt(getsub, fmt, args)
-int (*getsub)();
-register char *fmt;
-int **args;
+int scanfmt(int (*getsub)(), char *fmt, int **args)
 {
 
@@ -389,7 +379,5 @@
 */
 
-sscanf(string, fmt, args)
-char *string, *fmt;
-int *args;
+int sscanf(char *string, char *fmt, int *args)
 {
 	scnstr = string;
Index: libcio/setbuf.c
===================================================================
--- libcio/setbuf.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/setbuf.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -8,7 +8,5 @@
 #include "stdio.h"
 
-setbuf(stream, buffer)
-register FILE *stream;
-char *buffer;
+void setbuf(FILE *stream, char *buffer)
 {
 	if (stream->_buff)
Index: libcio/ungetc.c
===================================================================
--- libcio/ungetc.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/ungetc.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -9,8 +9,5 @@
 #include "stddefs.h"
 
-int
-ungetc(c, ptr)
-register int c;
-register FILE *ptr;
+int ungetc(int c, FILE *ptr)
 {
 	if ((c EQ EOF) OR (ptr->_bp LE ptr->_buff))
Index: libcio/unlink.c
===================================================================
--- libcio/unlink.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/unlink.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -17,5 +17,5 @@
 #endif
 
-extern	int	DelFile();
+extern	int	DelFile(struct fcb *fcp);
 
 /*
@@ -25,7 +25,5 @@
 */
 
-int
-unlink(name)
-char *name;
+int unlink(char *name)
 {
 	struct fcb delfcb;
Index: libcio/write.c
===================================================================
--- libcio/write.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/write.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -13,13 +13,18 @@
 #include "stddefs.h"
 
-int	_filewr();
-
-extern	int	_badfd(), _conwr(), blkwr();
-extern	int	ReadRN(), WriteRN();
-extern	int	_newcls(), micons(), _ptcl12();
-
-extern	long	miconl();
-
-extern	char	*memset();
+int	_filewr(struct fcb *fp, char *buffer, unsigned len);
+
+extern	int	_badfd(void);
+extern	int	_conwr(int kind, char *buff, int len);
+extern	int	blkwr(struct fcb *fcp, char *buf, int ns);
+extern	int	ReadRN(struct fcb *fcp, char *buf);
+extern	int	WriteRN(struct fcb *fcp, char *buf);
+extern	int	_newcls(void);
+extern	short	micons(short wi);
+extern	void	_ptcl12(unsigned *fat, unsigned cl, unsigned val);
+
+extern	long	miconl(long wi);
+
+extern	char	*memset(char *sp, char c, int n);
 
 extern	short	_fatmod;
@@ -50,9 +55,5 @@
 */
 
-int
-_putsec(fp, buf, len)
-register struct fcb *fp;
-char *buf;
-unsigned len;
+int _putsec(struct fcb *fp, char *buf, unsigned len)
 {
 #if DEBUGIT
@@ -125,9 +126,5 @@
 */
 
-int
-_filewr(fp, buffer, len)
-register struct fcb *fp;
-register char *buffer;
-register unsigned len;
+int _filewr(struct fcb *fp, char *buffer, unsigned len)
 {
 	register unsigned j, k, l;
@@ -248,9 +245,5 @@
 */
 
-int
-write(fd, buff, len)
-int fd;
-char *buff;
-unsigned len;
+int write(int fd, char *buff, unsigned len)
 {
 	register struct channel *chp;
Index: libcio/writern.c
===================================================================
--- libcio/writern.c	(revision 1127e68946488c825c8908c4b11f641470f94a44)
+++ libcio/writern.c	(revision 342a56fb7d496f8e81315e423dc9309308a74300)
@@ -23,5 +23,5 @@
 
 extern	long	_berrno;
-extern	int	_seek();
+extern	int	_seek(struct fcb *fcp);
 
 #if DEBUGIT
@@ -30,5 +30,5 @@
 
 #if	TBUFFER
-extern	long	_secwr();		/* update buffer function */
+extern	long	_secwr(char *buf, short rec);
 #endif
 
@@ -44,8 +44,5 @@
 */
 
-int
-WriteRN(fcp, buf)
-struct fcb *fcp;
-char *buf;
+int WriteRN(struct fcb *fcp, char *buf)
 {
 	int	sv;		/* seek return code */