diff -rup xc-orig/programs/Xserver/hw/xfree86/input/mouse/mouse.c xc/programs/Xserver/hw/xfree86/input/mouse/mouse.c
--- xc-orig/programs/Xserver/hw/xfree86/input/mouse/mouse.c	2003-02-10 19:33:06.000000000 -0800
+++ xc/programs/Xserver/hw/xfree86/input/mouse/mouse.c	2003-03-05 13:52:30.000000000 -0800
@@ -189,6 +189,7 @@ typedef enum {
     OPTION_X_AXIS_MAPPING,
     OPTION_Y_AXIS_MAPPING,
     OPTION_AUTO_SOFT,
+    OPTION_LOGITECH_SMS,
     OPTION_CLEAR_DTR,
     OPTION_CLEAR_RTS,
     OPTION_BAUD_RATE,
@@ -226,6 +227,7 @@ static const OptionInfoRec mouseOptions[
     { OPTION_X_AXIS_MAPPING,	"XAxisMapping",	  OPTV_STRING,	{0}, FALSE },
     { OPTION_Y_AXIS_MAPPING,	"YAxisMapping",	  OPTV_STRING,	{0}, FALSE },
     { OPTION_AUTO_SOFT,		"AutoSoft",	  OPTV_BOOLEAN, {0}, FALSE },
+    { OPTION_LOGITECH_SMS,	"SmartScroll",	  OPTV_INTEGER, {0}, FALSE },
     /* serial options */
     { OPTION_CLEAR_DTR,		"ClearDTR",	  OPTV_BOOLEAN,	{0}, FALSE },
     { OPTION_CLEAR_RTS,		"ClearRTS",	  OPTV_BOOLEAN,	{0}, FALSE },
@@ -700,6 +702,12 @@ MouseHWOptions(InputInfoPtr pInfo)
 	 = xf86SetBoolOption(pInfo->options, "AutoSoft", FALSE))) {
 	xf86Msg(X_CONFIG, "Don't initialize mouse when auto-probing\n");
     }
+    
+    pMse->smartScroll = xf86SetIntOption(pInfo->options, "SmartScroll", 1);
+    if (pMse->smartScroll) {
+        xf86Msg(X_CONFIG, "%s: SmartScroll: %d \n", pInfo->name,
+	        pMse->smartScroll);
+    }
     pMse->sampleRate = xf86SetIntOption(pInfo->options, "SampleRate", 0);
     if (pMse->sampleRate) {
 	xf86Msg(X_CONFIG, "%s: SampleRate: %d\n", pInfo->name,
@@ -1381,20 +1389,36 @@ MouseReadInput(InputInfoPtr pInfo)
 	    buttons = (pBuf[0] & 0x04) >> 1 |       /* Middle */
 		      (pBuf[0] & 0x02) >> 1 |       /* Right */
 		      (pBuf[0] & 0x01) << 2;        /* Left */
-	    dx = (pBuf[0] & 0x10) ? pBuf[1] - 256 : pBuf[1];
-	    if (((pBuf[0] & 0x48) == 0x48) &&
-		(abs(dx) > 191) &&
-		((((pBuf[2] & 0x03) << 2) | 0x02) == (pBuf[1] & 0x0f))) {
+	    
+	    /* 
+	     * PS2++ now uses 6 bits for type, 8 for data
+	     * 2 type bits were implied to be always-on
+	     */
+	    if ( ((pBuf[0] & 0x48) == 0x48) && ((pBuf[1] & 0x02) == 0x02) )
+	    {
 		/* extended data packet */
-		switch ((((pBuf[0] & 0x30) >> 2) | ((pBuf[1] & 0x30) >> 4))) {
-		case 1:		/* wheel data packet */
+		switch ( (pBuf[0] & 0x30) |
+			( (pBuf[1] & 0xf0) >> 4) ) {
+		case 0x0d:	/* P1 - wheel data, buttons 4, 5 packet */
+		    buttons |= ( pMse->lastButtons & ~0x18);
 		    buttons |= ((pBuf[2] & 0x10) ? 0x08 : 0) | /* 4th button */
 		               ((pBuf[2] & 0x20) ? 0x10 : 0);  /* 5th button */
 		    dx = dy = 0;
 		    dz = (pBuf[2] & 0x08) ? (pBuf[2] & 0x0f) - 16 :
 					    (pBuf[2] & 0x0f);
 		    break;
-		case 2:		/* Logitech reserves this packet type */
+		case 0x0e:	/* P2 - buttons 4,5,6,7,8,9,10 info - NEW */
+		    buttons |= ( pMse->lastButtons & ~0x3f8);
+		    buttons |= ((pBuf[2] & 0x7f) << 3);
+		    break;
+#if 0 
+		    /* 
+		     * formerly case 2: Logitech updated PS/2++ (MMPS2),
+		     * and I guess it broke compatibility with manufacturers
+		     * that were latching onto it
+		     * is this what PS2TPP I see in the Linux 2.5.x 
+		     * kernel source (psmouse.c) is for? 
+		     */
 		    /* 
 		     * IBM ScrollPoint uses this packet to encode its
 		     * stick movement.
@@ -1405,7 +1429,7 @@ MouseReadInput(InputInfoPtr pInfo)
 					    ((pBuf[2] >> 4) & 0x0f);
 		    dw = (pBuf[2] & 0x08) ? (pBuf[2] & 0x0f) - 16 :
 					    (pBuf[2] & 0x0f);
-		    break;
+#endif
 		case 0:		/* device type packet - shouldn't happen */
 		default:
 		    buttons |= (pMse->lastButtons & ~0x07);
@@ -2635,7 +2659,12 @@ initMouseHW(InputInfoPtr pInfo)
 				  pMse->resolution);
 	    } else {
 		unsigned char c2[2];
-		
+		unsigned char sms[] = { 0xe6,
+			0xe8, 0, 0xe8, 3,
+			0xe8, 0, 0xe8, 2,
+			0xe8, 0, 0xe8, 0,
+			0xe8, 0, 0xe8, 0 };
+
 		c = 0xE6;	/*230*/	/* 1:1 scaling */
 		if (!ps2SendPacket(pInfo,&c,1)) {
 		    if (!count--)
@@ -2664,6 +2693,18 @@ initMouseHW(InputInfoPtr pInfo)
 			return TRUE;
 		    goto REDO;
 		}
+		/* 
+		 * this is on by default, but some users (me)
+		 * like it off
+		 */
+		if (pMse->smartScroll) 
+			sms[16] |= 1;
+		if (!ps2SendPacket(pInfo, sms, 17)) {
+			if (!count--)
+				return TRUE;
+			goto REDO;
+		}
+
 		c2[0] = 0xE8; /*232*/	/* set device resolution */
 		if (pMse->resolution > 0) {
 		    if (pMse->resolution >= 200)
@@ -2677,11 +2718,20 @@ initMouseHW(InputInfoPtr pInfo)
 		} else {
 		    c2[1] = 2;
 		}
-		if (!ps2SendPacket(pInfo,c2,2)) {
+		if (pMse->resolution >= 800) {
+		/* for Logitech mice that support it */
+			unsigned char cpi800[] = { 0xe6, 0xe6, 0xe6, 0xe8, 3 };
+			if (!ps2SendPacket(pInfo, cpi800, 5)) {
+				if (!count--)
+					return TRUE;
+				goto REDO;
+			}
+		} else if (!ps2SendPacket(pInfo,c2,2)) {
 		    if (!count--)
 			return TRUE;
 		    goto REDO;
-		}
+		}	
+			
 		usleep(30000);
 		xf86FlushInput(pInfo->fd);
 		if (!ps2EnableDataReporting(pInfo)) {
--- xc/programs/Xserver/hw/xfree86/os-support/xf86OSmouse.h.orig	2004-08-11 15:06:24.000000000 -0400
+++ xc/programs/Xserver/hw/xfree86/os-support/xf86OSmouse.h	2004-08-11 15:07:13.000000000 -0400
@@ -268,6 +268,7 @@
     dataGoodProc	dataGood;
     int			angleOffset;
     pointer		pDragLock;	/* drag lock area */
+	int			smartScroll;
     int			xisbscale;	/* buffer size for 1 event */
 } MouseDevRec, *MouseDevPtr;