diff --git a/mach/minix/libsys/brk.c b/mach/minix/libsys/brk.c
index dac238afe..f6a037728 100644
--- a/mach/minix/libsys/brk.c
+++ b/mach/minix/libsys/brk.c
@@ -21,11 +21,11 @@ PUBLIC char *sbrk(incr)
 int incr;
 {
   char *newsize, *oldsize;
-  extern int endv, dorgv;
 
   oldsize = brksize;
   newsize = brksize + incr;
-  if (incr > 0 && newsize < oldsize) return( (char *) -1);
+  if (incr > 0 && newsize < oldsize || incr < 0 && newsize > oldsize)
+	return( (char *) -1);
   if (brk(newsize) == 0)
 	return(oldsize);
   else
diff --git a/mach/minix/libsys/exec.c b/mach/minix/libsys/exec.c
index 26189e1dc..cb2be5520 100644
--- a/mach/minix/libsys/exec.c
+++ b/mach/minix/libsys/exec.c
@@ -1,6 +1,6 @@
 #include "lib.h"
 
-char *nullptr[1];		/* the EXEC calls need a zero pointer */
+extern char **environ;			/* environment pointer */
 
 #define	PTRSIZE	sizeof(char *)
 
@@ -8,7 +8,7 @@ PUBLIC int execl(name, arg0)
 char *name;
 char *arg0;
 {
-  return execve(name, &arg0, nullptr);
+  return execve(name, &arg0, environ);
 }
 
 PUBLIC int execle(name, argv)
@@ -23,7 +23,7 @@ char *name, *argv;
 PUBLIC int execv(name, argv)
 char *name, *argv[];
 {
-  return execve(name, argv, nullptr);
+  return execve(name, argv, environ);
 }
 
 
diff --git a/mach/minix/libsys/ioctl.c b/mach/minix/libsys/ioctl.c
index a46a733eb..fbd0658f4 100644
--- a/mach/minix/libsys/ioctl.c
+++ b/mach/minix/libsys/ioctl.c
@@ -11,28 +11,29 @@ union {
 } u;
 
 {
-  int n;
-  long erase, kill, intr, quit, xon, xoff, eof, brk;
+  int n, ispeed, ospeed;
+  long erase, kill, intr, quit, xon, xoff, eof, brk, speed;
 
   M.TTY_REQUEST = request;
   M.TTY_LINE = fd;
 
   switch(request) {
      case TIOCSETP:
-	erase = u.argp->sg_erase & 0377;
-	kill = u.argp->sg_kill & 0377;
+	erase = u.argp->sg_erase & BYTE;
+	kill = u.argp->sg_kill & BYTE;
 	M.TTY_SPEK = (erase << 8) | kill;
 	M.TTY_FLAGS = u.argp->sg_flags;
+	M.TTY_SPEED = (u.argp->sg_ospeed << 8) | u.argp->sg_ispeed;
 	n = callx(FS, IOCTL);
   	return(n);
  
      case TIOCSETC:
-  	intr = u.argt->t_intrc & 0377;
-  	quit = u.argt->t_quitc & 0377;
-  	xon  = u.argt->t_startc & 0377;
-  	xoff = u.argt->t_stopc & 0377;
-  	eof  = u.argt->t_eofc & 0377;
-  	brk  = u.argt->t_brkc & 0377;		/* not used at the moment */
+  	intr = u.argt->t_intrc & BYTE;
+  	quit = u.argt->t_quitc & BYTE;
+  	xon  = u.argt->t_startc & BYTE;
+  	xoff = u.argt->t_stopc & BYTE;
+  	eof  = u.argt->t_eofc & BYTE;
+  	brk  = u.argt->t_brkc & BYTE;		/* not used at the moment */
   	M.TTY_SPEK = (intr<<24) | (quit<<16) | (xon<<8) | (xoff<<0);
   	M.TTY_FLAGS = (eof<<8) | (brk<<0);
   	n = callx(FS, IOCTL);
@@ -40,19 +41,22 @@ union {
   	
      case TIOCGETP:
   	n = callx(FS, IOCTL);
-	u.argp->sg_erase = (M.TTY_SPEK >> 8) & 0377;
-	u.argp->sg_kill  = (M.TTY_SPEK >> 0) & 0377;
-  	u.argp->sg_flags = M.TTY_FLAGS;
+	u.argp->sg_erase = (M.TTY_SPEK >> 8) & BYTE;
+	u.argp->sg_kill  = (M.TTY_SPEK >> 0) & BYTE;
+  	u.argp->sg_flags = M.TTY_FLAGS & 0xFFFF;
+	speed = (M.TTY_FLAGS >> 16) & 0xFFFFL;
+	u.argp->sg_ispeed = speed & BYTE;
+	u.argp->sg_ospeed = (speed >> 8) & BYTE;
   	return(n);
 
      case TIOCGETC:
   	n = callx(FS, IOCTL);
-  	u.argt->t_intrc  = (M.TTY_SPEK >> 24) & 0377;
-  	u.argt->t_quitc  = (M.TTY_SPEK >> 16) & 0377;
-  	u.argt->t_startc = (M.TTY_SPEK >>  8) & 0377;
-  	u.argt->t_stopc  = (M.TTY_SPEK >>  0) & 0377;
-  	u.argt->t_eofc   = (M.TTY_FLAGS >> 8) & 0377;
-  	u.argt->t_brkc   = (M.TTY_FLAGS >> 8) & 0377;
+  	u.argt->t_intrc  = (M.TTY_SPEK >> 24) & BYTE;
+  	u.argt->t_quitc  = (M.TTY_SPEK >> 16) & BYTE;
+  	u.argt->t_startc = (M.TTY_SPEK >>  8) & BYTE;
+  	u.argt->t_stopc  = (M.TTY_SPEK >>  0) & BYTE;
+  	u.argt->t_eofc   = (M.TTY_FLAGS >> 8) & BYTE;
+  	u.argt->t_brkc   = (M.TTY_FLAGS >> 8) & BYTE;
   	return(n);
 
      default:
diff --git a/mach/minix/libsys/syslib.c b/mach/minix/libsys/syslib.c
index fd696bc0a..182b296ee 100644
--- a/mach/minix/libsys/syslib.c
+++ b/mach/minix/libsys/syslib.c
@@ -150,6 +150,18 @@ phys_clicks *basep, *sizep;	/* base and size for free_mem() */
 #endif
 
 
+PUBLIC sys_kill(proc, sig)
+int proc;			/* which proc has exited */
+int sig;			/* signal number: 1 - 16 */
+{
+/* A proc has to be signaled via MM.  Tell the kernel. */
+
+  M.m6_i1 = proc;
+  M.m6_i2 = sig;
+  callx(SYSTASK, SYS_KILL);
+}
+
+
 PUBLIC int tell_fs(what, p1, p2, p3)
 int what, p1, p2, p3;
 {
diff --git a/mach/minix/libsys/wait.c b/mach/minix/libsys/wait.c
index c1472a093..2d8728fd2 100644
--- a/mach/minix/libsys/wait.c
+++ b/mach/minix/libsys/wait.c
@@ -5,6 +5,6 @@ int *status;
 {
   int k;
   k = callm1(MM, WAIT, 0, 0, 0, NIL_PTR, NIL_PTR, NIL_PTR);
-  if (status != 0) *status = M.m2_i1;
+  if (k >= 0 && status != 0) *status = M.m2_i1;
   return(k);
 }
diff --git a/mach/minixST/libsys/brk.c b/mach/minixST/libsys/brk.c
index dac238afe..f6a037728 100644
--- a/mach/minixST/libsys/brk.c
+++ b/mach/minixST/libsys/brk.c
@@ -21,11 +21,11 @@ PUBLIC char *sbrk(incr)
 int incr;
 {
   char *newsize, *oldsize;
-  extern int endv, dorgv;
 
   oldsize = brksize;
   newsize = brksize + incr;
-  if (incr > 0 && newsize < oldsize) return( (char *) -1);
+  if (incr > 0 && newsize < oldsize || incr < 0 && newsize > oldsize)
+	return( (char *) -1);
   if (brk(newsize) == 0)
 	return(oldsize);
   else
diff --git a/mach/minixST/libsys/exec.c b/mach/minixST/libsys/exec.c
index 26189e1dc..cb2be5520 100644
--- a/mach/minixST/libsys/exec.c
+++ b/mach/minixST/libsys/exec.c
@@ -1,6 +1,6 @@
 #include "lib.h"
 
-char *nullptr[1];		/* the EXEC calls need a zero pointer */
+extern char **environ;			/* environment pointer */
 
 #define	PTRSIZE	sizeof(char *)
 
@@ -8,7 +8,7 @@ PUBLIC int execl(name, arg0)
 char *name;
 char *arg0;
 {
-  return execve(name, &arg0, nullptr);
+  return execve(name, &arg0, environ);
 }
 
 PUBLIC int execle(name, argv)
@@ -23,7 +23,7 @@ char *name, *argv;
 PUBLIC int execv(name, argv)
 char *name, *argv[];
 {
-  return execve(name, argv, nullptr);
+  return execve(name, argv, environ);
 }
 
 
diff --git a/mach/minixST/libsys/ioctl.c b/mach/minixST/libsys/ioctl.c
index a46a733eb..fbd0658f4 100644
--- a/mach/minixST/libsys/ioctl.c
+++ b/mach/minixST/libsys/ioctl.c
@@ -11,28 +11,29 @@ union {
 } u;
 
 {
-  int n;
-  long erase, kill, intr, quit, xon, xoff, eof, brk;
+  int n, ispeed, ospeed;
+  long erase, kill, intr, quit, xon, xoff, eof, brk, speed;
 
   M.TTY_REQUEST = request;
   M.TTY_LINE = fd;
 
   switch(request) {
      case TIOCSETP:
-	erase = u.argp->sg_erase & 0377;
-	kill = u.argp->sg_kill & 0377;
+	erase = u.argp->sg_erase & BYTE;
+	kill = u.argp->sg_kill & BYTE;
 	M.TTY_SPEK = (erase << 8) | kill;
 	M.TTY_FLAGS = u.argp->sg_flags;
+	M.TTY_SPEED = (u.argp->sg_ospeed << 8) | u.argp->sg_ispeed;
 	n = callx(FS, IOCTL);
   	return(n);
  
      case TIOCSETC:
-  	intr = u.argt->t_intrc & 0377;
-  	quit = u.argt->t_quitc & 0377;
-  	xon  = u.argt->t_startc & 0377;
-  	xoff = u.argt->t_stopc & 0377;
-  	eof  = u.argt->t_eofc & 0377;
-  	brk  = u.argt->t_brkc & 0377;		/* not used at the moment */
+  	intr = u.argt->t_intrc & BYTE;
+  	quit = u.argt->t_quitc & BYTE;
+  	xon  = u.argt->t_startc & BYTE;
+  	xoff = u.argt->t_stopc & BYTE;
+  	eof  = u.argt->t_eofc & BYTE;
+  	brk  = u.argt->t_brkc & BYTE;		/* not used at the moment */
   	M.TTY_SPEK = (intr<<24) | (quit<<16) | (xon<<8) | (xoff<<0);
   	M.TTY_FLAGS = (eof<<8) | (brk<<0);
   	n = callx(FS, IOCTL);
@@ -40,19 +41,22 @@ union {
   	
      case TIOCGETP:
   	n = callx(FS, IOCTL);
-	u.argp->sg_erase = (M.TTY_SPEK >> 8) & 0377;
-	u.argp->sg_kill  = (M.TTY_SPEK >> 0) & 0377;
-  	u.argp->sg_flags = M.TTY_FLAGS;
+	u.argp->sg_erase = (M.TTY_SPEK >> 8) & BYTE;
+	u.argp->sg_kill  = (M.TTY_SPEK >> 0) & BYTE;
+  	u.argp->sg_flags = M.TTY_FLAGS & 0xFFFF;
+	speed = (M.TTY_FLAGS >> 16) & 0xFFFFL;
+	u.argp->sg_ispeed = speed & BYTE;
+	u.argp->sg_ospeed = (speed >> 8) & BYTE;
   	return(n);
 
      case TIOCGETC:
   	n = callx(FS, IOCTL);
-  	u.argt->t_intrc  = (M.TTY_SPEK >> 24) & 0377;
-  	u.argt->t_quitc  = (M.TTY_SPEK >> 16) & 0377;
-  	u.argt->t_startc = (M.TTY_SPEK >>  8) & 0377;
-  	u.argt->t_stopc  = (M.TTY_SPEK >>  0) & 0377;
-  	u.argt->t_eofc   = (M.TTY_FLAGS >> 8) & 0377;
-  	u.argt->t_brkc   = (M.TTY_FLAGS >> 8) & 0377;
+  	u.argt->t_intrc  = (M.TTY_SPEK >> 24) & BYTE;
+  	u.argt->t_quitc  = (M.TTY_SPEK >> 16) & BYTE;
+  	u.argt->t_startc = (M.TTY_SPEK >>  8) & BYTE;
+  	u.argt->t_stopc  = (M.TTY_SPEK >>  0) & BYTE;
+  	u.argt->t_eofc   = (M.TTY_FLAGS >> 8) & BYTE;
+  	u.argt->t_brkc   = (M.TTY_FLAGS >> 8) & BYTE;
   	return(n);
 
      default:
diff --git a/mach/minixST/libsys/syslib.c b/mach/minixST/libsys/syslib.c
index fd696bc0a..182b296ee 100644
--- a/mach/minixST/libsys/syslib.c
+++ b/mach/minixST/libsys/syslib.c
@@ -150,6 +150,18 @@ phys_clicks *basep, *sizep;	/* base and size for free_mem() */
 #endif
 
 
+PUBLIC sys_kill(proc, sig)
+int proc;			/* which proc has exited */
+int sig;			/* signal number: 1 - 16 */
+{
+/* A proc has to be signaled via MM.  Tell the kernel. */
+
+  M.m6_i1 = proc;
+  M.m6_i2 = sig;
+  callx(SYSTASK, SYS_KILL);
+}
+
+
 PUBLIC int tell_fs(what, p1, p2, p3)
 int what, p1, p2, p3;
 {
diff --git a/mach/minixST/libsys/wait.c b/mach/minixST/libsys/wait.c
index c1472a093..2d8728fd2 100644
--- a/mach/minixST/libsys/wait.c
+++ b/mach/minixST/libsys/wait.c
@@ -5,6 +5,6 @@ int *status;
 {
   int k;
   k = callm1(MM, WAIT, 0, 0, 0, NIL_PTR, NIL_PTR, NIL_PTR);
-  if (status != 0) *status = M.m2_i1;
+  if (k >= 0 && status != 0) *status = M.m2_i1;
   return(k);
 }