Don't require keyboard and mouse together.
 [rsc] --rw-rw-r-- M 140560 glenda sys 12362 Nov  1 07:31 sys/src/9/pc/kbd.c
	/n/sourcesdump/2005/1101/plan9/sys/src/9/pc/kbd.c:6,13 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/pc/kbd.c:6,11
	  #include	"io.h"
	  #include	"../port/error.h"
	  
	- extern void mousetrack(int, int, int, int);
	- 
	  enum {
	  	Data=		0x60,		/* data port */
	  
	/n/sourcesdump/2005/1101/plan9/sys/src/9/pc/kbd.c:170,176 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/pc/kbd.c:168,174
	  };
	  
	  int mouseshifted;
	- int kbdbuttons;
	+ void (*kbdmouse)(int);
	  
	  static Lock i8042lock;
	  static uchar ccc;
	/n/sourcesdump/2005/1101/plan9/sys/src/9/pc/kbd.c:304,309 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/pc/kbd.c:302,308
	  	int collecting;
	  	int nk;
	  	Rune kc[5];
	+ 	int buttons;
	  } kbscan;
	  
	  /*
	/n/sourcesdump/2005/1101/plan9/sys/src/9/pc/kbd.c:402,409 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/pc/kbd.c:401,409
	  		case Kmouse|3:
	  		case Kmouse|4:
	  		case Kmouse|5:
	- 			kbdbuttons &= ~(1<<(c-Kmouse-1));
	- 			mousetrack(0, 0, 0, TK2MS(MACHP(0)->ticks));
	+ 			kbscan.buttons &= ~(1<<(c-Kmouse-1));
	+ 			if(kbdmouse)
	+ 				kbdmouse(kbscan.buttons);
	  			break;
	  		}
	  		return;
	/n/sourcesdump/2005/1101/plan9/sys/src/9/pc/kbd.c:473,480 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/pc/kbd.c:473,481
	  		case Kmouse|3:
	  		case Kmouse|4:
	  		case Kmouse|5:
	- 			kbdbuttons |= 1<<(c-Kmouse-1);
	- 			mousetrack(0, 0, 0, TK2MS(MACHP(0)->ticks));
	+ 			kbscan.buttons |= 1<<(c-Kmouse-1);
	+ 			if(kbdmouse)
	+ 				kbdmouse(kbscan.buttons);
	  			return;
	  		}
	  	}
 [rsc] --rw-rw-r-- M 140560 glenda sys 13517 Nov  1 07:31 sys/src/9/port/devmouse.c
	/n/sourcesdump/2005/1101/plan9/sys/src/9/port/devmouse.c:73,83 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/port/devmouse.c:73,85
	  Cursorinfo	cursor;
	  int		mouseshifted;
	  int		kbdbuttons;
	+ void		(*kbdmouse)(int);
	  Cursor		curs;
	  
	  void	Cursortocursor(Cursor*);
	  int	mousechanged(void*);
	  static void mouseclock(void);
	+ static void xkbdmouse(int);
	  
	  enum{
	  	Qdir,
	/n/sourcesdump/2005/1101/plan9/sys/src/9/port/devmouse.c:115,120 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/port/devmouse.c:117,129
	  }
	  
	  static void
	+ mousefromkbd(int buttons)
	+ {
	+ 	kbdbuttons = buttons;
	+ 	mousetrack(0, 0, 0, TK2MS(MACHP(0)->ticks));
	+ }
	+ 
	+ static void
	  mouseinit(void)
	  {
	  	if(!conf.monitor)
	/n/sourcesdump/2005/1101/plan9/sys/src/9/port/devmouse.c:123,128 - 
	/n/sourcesdump/2005/1102/plan9/sys/src/9/port/devmouse.c:132,138
	  	curs = arrow;
	  	Cursortocursor(&arrow);
	  	cursoron(1);
	+ 	kbdmouse = mousefromkbd;
	  }
	  
	  static Chan*