diff --git a/examples/veinlook.cpp b/examples/veinlook.cpp
index 5d1e7bbda..91a21f566 100644
--- a/examples/veinlook.cpp
+++ b/examples/veinlook.cpp
@@ -337,6 +337,7 @@ main(int argc, char *argv[])
     int filenum = 0;
     bool dirtybit = false;
     uint32_t blockaddr = 0;
+    uint32_t blockaddr2 = 0;
     // walk the map!
     for (;;)
     {
@@ -437,6 +438,7 @@ main(int argc, char *argv[])
                     if(i == 0 && j == 0)
                     {
                         blockaddr = DF.getBlockPtr(cursorX+i,cursorY+j,cursorZ);
+                        blockaddr2 = Block.origin;
                         if(dump)
                         {
                             hexdump(DF,blockaddr,0x1E00/*0x1DB8*/,filenum);
@@ -516,7 +518,7 @@ main(int argc, char *argv[])
             }
         }
         gotoxy (0,52);
-        cprintf("block address 0x%x",blockaddr);
+        cprintf("block address 0x%x 0x%x",blockaddr, blockaddr2);
         gotoxy (0,53);
         cprintf("dirty bit: %d",dirtybit);
         gotoxy (0,54);
diff --git a/library/DFHackAPI.cpp b/library/DFHackAPI.cpp
index 0dc311609..88cde1396 100644
--- a/library/DFHackAPI.cpp
+++ b/library/DFHackAPI.cpp
@@ -316,6 +316,7 @@ bool API::ReadBlock40d(uint32_t x, uint32_t y, uint32_t z, mapblock40d * buffer)
             g_pProcess->read (addr + d->occupancy_offset, sizeof (buffer->occupancy), (uint8_t *) buffer->occupancy);
             g_pProcess->read (addr + d->designation_offset, sizeof (buffer->designaton), (uint8_t *) buffer->designaton);
             g_pProcess->read (addr + d->biome_stuffs, sizeof (buffer->biome_indices), (uint8_t *) buffer->biome_indices);
+            buffer->origin = addr;
             uint32_t addr_of_struct = g_pProcess->readDWord(addr);
             buffer->dirty_dword = g_pProcess->readDWord(addr_of_struct);
             return true;
diff --git a/library/DFTypes.h b/library/DFTypes.h
index db47c23fc..6b9e467a5 100644
--- a/library/DFTypes.h
+++ b/library/DFTypes.h
@@ -769,7 +769,9 @@ typedef struct
     int16_t tiletypes [16][16];
     DFHack::t_designation designaton [16][16];
     DFHack::t_occupancy occupancy [16][16];
-    uint8_t biome_indices [7];
+    // really a '7', but I use 8 to make it neater :)
+    uint8_t biome_indices [8];
+    uint32_t origin; // the address where it came from
     uint32_t dirty_dword; // bit 1 set means that the block is to be included in job checks
 } mapblock40d;
 
diff --git a/shmserver/CMakeLists.txt b/shmserver/CMakeLists.txt
index 75c007678..cc4b8cc57 100644
--- a/shmserver/CMakeLists.txt
+++ b/shmserver/CMakeLists.txt
@@ -38,15 +38,16 @@ SET_SOURCE_FILES_PROPERTIES( ${PROJECT_HDRS} PROPERTIES HEADER_FILE_ONLY TRUE )
 
 LIST(APPEND PROJECT_SRCS ${PROJECT_HDRS})
 
-IF(UNIX)
-    add_definitions(-DLINUX_BUILD)
-    SET(PROJECT_LIBS rt)
-    SET(CMAKE_CXX_FLAGS "-fvisibility=hidden")
-    ADD_LIBRARY(dfconnect SHARED ${PROJECT_SRCS})
-    TARGET_LINK_LIBRARIES(dfconnect ${PROJECT_LIBS})
-ELSE(UNIX)
-    #  SET(PROJECT_LIBS psapi)
-    ADD_LIBRARY(SDL SHARED ${PROJECT_SRCS})
-    TARGET_LINK_LIBRARIES(SDL ${PROJECT_LIBS})
-ENDIF(UNIX)
-
+IF(CMAKE_SIZEOF_VOID_P EQUAL 4)
+    IF(UNIX)
+        add_definitions(-DLINUX_BUILD)
+        SET(PROJECT_LIBS rt)
+        SET(CMAKE_CXX_FLAGS "-fvisibility=hidden")
+        ADD_LIBRARY(dfconnect SHARED ${PROJECT_SRCS})
+        TARGET_LINK_LIBRARIES(dfconnect ${PROJECT_LIBS})
+    ELSE(UNIX)
+        #  SET(PROJECT_LIBS psapi)
+        ADD_LIBRARY(SDL SHARED ${PROJECT_SRCS})
+        TARGET_LINK_LIBRARIES(SDL ${PROJECT_LIBS})
+    ENDIF(UNIX)
+ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 4)
diff --git a/shmserver/mod-maps.cpp b/shmserver/mod-maps.cpp
index a67d040db..a34f01975 100644
--- a/shmserver/mod-maps.cpp
+++ b/shmserver/mod-maps.cpp
@@ -77,6 +77,8 @@ void ReadBlockByCoords (void * data)
         memcpy(&(SHMBLOCK->occupancy), block + offsets.occupancy_offset, sizeof(SHMBLOCK->occupancy));
         memcpy(&(SHMBLOCK->biome_indices), block + offsets.biome_stuffs, sizeof(SHMBLOCK->biome_indices));
         SHMBLOCK->dirty_dword = *block->ptr_to_dirty;
+        
+        SHMBLOCK->origin = reinterpret_cast<uint32_t>(block);
         SHMHDR->error = false;
     }
     else