diff --git a/src_rebuild/Game/ASM/d2mapasm.c b/src_rebuild/Game/ASM/d2mapasm.c
index 203dffb8..84d85d01 100644
--- a/src_rebuild/Game/ASM/d2mapasm.c
+++ b/src_rebuild/Game/ASM/d2mapasm.c
@@ -98,7 +98,7 @@ sdPlane* sdGetCell_alpha16(VECTOR* pos)
 	cellPos_z = pos->vz - 512;
 
 	buffer = *(short**)((int)RoadMapDataRegions + (cellPos_x >> 14 & 4U ^ cellPos_z >> 13 & 8U ^ sdSelfModifyingCode));	// pointless, but i'll keep it there
-
+	
 	cell.x = cellPos_x & 1023;
 	cell.y = cellPos_z & 1023;
 
@@ -170,7 +170,8 @@ int RoadInCell_alpha16(VECTOR *pos)
 	cellPos_x = pos->vx - 512;
 	cellPos_z = pos->vz - 512;
 	
-	buffer = RoadMapDataRegions[cellPos_x >> 0x10 & 1U ^ (cells_across >> 6 & 1U) + (cellPos_z >> 0xf & 2U) ^ cells_down >> 5 & 2U];
+	buffer = RoadMapDataRegions[(cellPos_x >> 16 & 1U) ^ (regions_across / 2 & 1) +
+								(cellPos_z >> 15 & 2U) ^ (regions_down & 2)];
 	
 	if (*buffer == 2) 
 	{
diff --git a/src_rebuild/Game/C/dr2roads.c b/src_rebuild/Game/C/dr2roads.c
index c1134ef9..37c7b014 100644
--- a/src_rebuild/Game/C/dr2roads.c
+++ b/src_rebuild/Game/C/dr2roads.c
@@ -254,7 +254,7 @@ int sdHeightOnPlane(VECTOR *pos, sdPlane *plane)
 		if ((plane->surface & 0xE000) == 0x4000 && plane->b == 0)
 		{
 			// calculate curve point
-			curve = Driver2CurvesPtr + ((plane->surface & 0x1fff) - 32);
+			curve = &Driver2CurvesPtr[(plane->surface & 0x1fff) - 32];
 			angle = ratan2(curve->Midz - pos->vz, curve->Midx - pos->vx);
 
 			return ((curve->gradient * (angle + 2048 & 0xfff)) / ONE) - curve->height;
@@ -324,13 +324,14 @@ sdPlane* sdGetCell(VECTOR *pos)
 	// [A] WARNING!
 	// retail version of game with exe dated before 20th October 2000 (so called 1.0) is only supported
 	// the later version of the game do have problem with height or BSP, so Havana's secret base ground is not solid
-
-	// Oct 17 2000:			RoadMapDataRegions[(v4 >> 16) & 1 ^ (((cells_across >> 6) & 1) + (((v3 - 512) >> 15) & 2)) ^ (cells_down >> 5) & 2];
-	// Oct 29 2000:			RoadMapDataRegions[(cellPos.x >> 16) & 1 ^ (((cellPos.y >> 15) & 2) + 1) ^ 2];
+	// reason is unknown
 
 	buffer = RoadMapDataRegions[(cellPos.x >> 16 & 1U) ^ (regions_across / 2 & 1) + 
 								(cellPos.y >> 15 & 2U) ^ (regions_down & 2)];
 
+	// Alpha 1.6 code, works too; not widely tested yet
+	//buffer = *(short**)((int)RoadMapDataRegions + (cellPos.x >> 14 & 4U ^ cellPos.y >> 13 & 8U ^ sdSelfModifyingCode));
+
 	plane = NULL;
 	
 	if (*buffer == 2)