Apply by doing
	cd /sys
	patch -p0 < apm.patch

*** arch/i386/i386/apm.c.orig	Wed Dec 10 20:11:23 1997
--- arch/i386/i386/apm.c	Wed Dec 10 20:12:14 1997
***************
*** 746,757 ****
  	int flag, mode;
  	struct proc *p;
  {
! 	struct apm_softc *sc = apm_cd.cd_devs[APMUNIT(dev)];
  
  	/* apm0 only */
! 	if (APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
  	switch (APMDEV(dev)) {
  	case APMDEV_CTL:
  		if (!(flag & FWRITE))
--- 746,759 ----
  	int flag, mode;
  	struct proc *p;
  {
! 	struct apm_softc *sc;
  
  	/* apm0 only */
! 	if (!apm_cd.cd_ndevs || APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
+ 	sc = apm_cd.cd_devs[APMUNIT(dev)];
+ 
  	switch (APMDEV(dev)) {
  	case APMDEV_CTL:
  		if (!(flag & FWRITE))
***************
*** 778,789 ****
  	int flag, mode;
  	struct proc *p;
  {
! 	struct apm_softc *sc = apm_cd.cd_devs[APMUNIT(dev)];
  
  	/* apm0 only */
! 	if (APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
  	DPRINTF(("apmclose: pid %d flag %x mode %x\n", p->p_pid, flag, mode));
  
  	switch (APMDEV(dev)) {
--- 780,793 ----
  	int flag, mode;
  	struct proc *p;
  {
! 	struct apm_softc *sc;
  
  	/* apm0 only */
! 	if (!apm_cd.cd_ndevs || APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
+ 	sc = apm_cd.cd_devs[APMUNIT(dev)];
+ 
  	DPRINTF(("apmclose: pid %d flag %x mode %x\n", p->p_pid, flag, mode));
  
  	switch (APMDEV(dev)) {
***************
*** 809,815 ****
  	int flag;
  	struct proc *p;
  {
! 	struct apm_softc *sc = apm_cd.cd_devs[APMUNIT(dev)];
  	struct apm_power_info *powerp;
  	struct apm_event_info *evp;
  	struct apmregs regs;
--- 813,819 ----
  	int flag;
  	struct proc *p;
  {
! 	struct apm_softc *sc;
  	struct apm_power_info *powerp;
  	struct apm_event_info *evp;
  	struct apmregs regs;
***************
*** 817,825 ****
  	struct apm_ctl *actl;
  
  	/* apm0 only */
! 	if (APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
  	switch (cmd) {
  		/* some ioctl names from linux */
  	case APM_IOC_STANDBY:
--- 821,831 ----
  	struct apm_ctl *actl;
  
  	/* apm0 only */
! 	if (!apm_cd.cd_ndevs || APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
+ 	sc = apm_cd.cd_devs[APMUNIT(dev)];
+ 
  	switch (cmd) {
  		/* some ioctl names from linux */
  	case APM_IOC_STANDBY:
***************
*** 901,912 ****
  	int rw;
  	struct proc *p;
  {
! 	struct apm_softc *sc = apm_cd.cd_devs[APMUNIT(dev)];
  
  	/* apm0 only */
! 	if (APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
  	switch (rw) {
  	case FREAD:
  		if (sc->event_count)
--- 907,920 ----
  	int rw;
  	struct proc *p;
  {
! 	struct apm_softc *sc;
  
  	/* apm0 only */
! 	if (!apm_cd.cd_ndevs || APMUNIT(dev) != 0 || sc == NULL)
  		return ENXIO;
  	
+ 	sc = apm_cd.cd_devs[APMUNIT(dev)];
+ 
  	switch (rw) {
  	case FREAD:
  		if (sc->event_count)