--- /n/sources/plan9/sys/src/cmd/cpu.c	Thu Jul 22 22:25:23 2010
+++ /sys/src/cmd/cpu.c	Sun Feb 28 00:00:00 2016
@@ -15,7 +15,7 @@
 #define	Maxfdata 8192
 #define MaxStr 128
 
-void	remoteside(int);
+void	remoteside(void);
 void	fatal(int, char*, ...);
 void	lclnoteproc(int);
 void	rmtnoteproc(void);
@@ -171,12 +171,8 @@
 	case 'f':
 		/* ignored but accepted for compatibility */
 		break;
-	case 'O':
-		p9authproto = "p9sk2";
-		remoteside(1);				/* From listen */
-		break;
 	case 'R':				/* From listen */
-		remoteside(0);
+		remoteside();
 		break;
 	case 'h':
 		system = EARGF(usage());
@@ -285,49 +281,9 @@
 
 char *negstr = "negotiating authentication method";
 
-char bug[256];
-
-int
-old9p(int fd)
-{
-	int p[2];
-
-	if(pipe(p) < 0)
-		fatal(1, "pipe");
-
-	switch(rfork(RFPROC|RFFDG|RFNAMEG)) {
-	case -1:
-		fatal(1, "rfork srvold9p");
-	case 0:
-		if(fd != 1){
-			dup(fd, 1);
-			close(fd);
-		}
-		if(p[0] != 0){
-			dup(p[0], 0);
-			close(p[0]);
-		}
-		close(p[1]);
-		if(0){
-			fd = open("/sys/log/cpu", OWRITE);
-			if(fd != 2){
-				dup(fd, 2);
-				close(fd);
-			}
-			execl("/bin/srvold9p", "srvold9p", "-ds", nil);
-		} else
-			execl("/bin/srvold9p", "srvold9p", "-s", nil);
-		fatal(1, "exec srvold9p");
-	default:
-		close(fd);
-		close(p[0]);
-	}
-	return p[1];	
-}
-
 /* Invoked with stdin, stdout and stderr connected to the network connection */
 void
-remoteside(int old)
+remoteside(void)
 {
 	char user[MaxStr], home[MaxStr], buf[MaxStr], xdir[MaxStr], cmd[MaxStr];
 	int i, n, fd, badchdir, gotcmd;
@@ -384,9 +340,6 @@
 	if(n != 2 || buf[0] != 'O' || buf[1] != 'K')
 		exits("remote tree");
 
-	if(old)
-		fd = old9p(fd);
-
 	/* make sure buffers are big by doing fversion explicitly; pick a huge number; other side will trim */
 	strcpy(buf, VERSION9P);
 	if(fversion(fd, 64*1024, buf, sizeof buf) < 0)
--- /n/sources/plan9/sys/man/1/cpu	Sun Dec  2 23:42:11 2007
+++ /sys/man/1/cpu	Sun Feb 28 00:00:00 2016
@@ -29,8 +29,6 @@
 .B cpu
 [
 .B -R
-|
-.B -O
 ]
 .SH DESCRIPTION
 .I Cpu
@@ -170,12 +168,6 @@
 to run the server (remote) side of the protocol.
 It is run from service files such as
 .BR /bin/service/tcp17010 .
-The
-.B -O
-flag is similar but simulates the pre-9P2000 version
-of the 
-.I cpu
-protocol.
 .SH FILES
 The name space of the terminal side of the
 .I cpu