diff --git a/src/mame/machine/n64.c b/src/mame/machine/n64.c
index 9c48789101d..de5cb0f72c8 100644
--- a/src/mame/machine/n64.c
+++ b/src/mame/machine/n64.c
@@ -1215,6 +1215,8 @@ void n64_periphs::pi_dma_tick()
 	UINT32 cart_addr = (pi_cart_addr & 0x0fffffff) >> 1;
 	UINT32 dram_addr = (pi_dram_addr & 0x007fffff) >> 1;
 
+    cart_addr &= ((machine().region("user2")->bytes() >> 1) - 1);
+
 	if(pi_dma_dir == 1)
 	{
 		UINT32 dma_length = pi_wr_len + 1;
diff --git a/src/mame/video/n64.c b/src/mame/video/n64.c
index 08668350816..d3771aae566 100644
--- a/src/mame/video/n64.c
+++ b/src/mame/video/n64.c
@@ -118,6 +118,11 @@ void Processor::VideoUpdate16(n64_periphs *n64, bitmap_rgb32 &bitmap)
 		hres = 640;
 	}
 
+    if (vres > bitmap.height()) // makes Perfect Dark boot w/o crashing
+    {
+        vres = bitmap.height();
+    }
+
 	UINT32 pixels = 0;
 
 	if (frame_buffer)