--- a/backend.c	Sun Feb 10 11:58:23 2019 -0800
+++ b/backend.c	Tue Feb 12 09:58:04 2019 -0800
@@ -93,6 +93,31 @@
 	return NULL;
 }
 
+void * get_native_write_pointer(uint32_t address, void ** mem_pointers, cpu_options * opts)
+{
+	memmap_chunk const * memmap = opts->memmap;
+	address &= opts->address_mask;
+	for (uint32_t chunk = 0; chunk < opts->memmap_chunks; chunk++)
+	{
+		if (address >= memmap[chunk].start && address < memmap[chunk].end) {
+			if (!(memmap[chunk].flags & (MMAP_WRITE))) {
+				return NULL;
+			}
+			uint8_t * base = memmap[chunk].flags & MMAP_PTR_IDX
+				? mem_pointers[memmap[chunk].ptr_index]
+				: memmap[chunk].buffer;
+			if (!base) {
+				if (memmap[chunk].flags & MMAP_AUX_BUFF) {
+					return memmap[chunk].buffer + (address & memmap[chunk].aux_mask);
+				}
+				return NULL;
+			}
+			return base + (address & memmap[chunk].mask);
+		}
+	}
+	return NULL;
+}
+
 uint16_t read_word(uint32_t address, void **mem_pointers, cpu_options *opts, void *context)
 {
 	memmap_chunk const *chunk = find_map_chunk(address, opts, 0, NULL);