diff --git a/src/vid_cga.c b/src/vid_cga.c
index 247dbf3..4f3d8c4 100644
--- a/src/vid_cga.c
+++ b/src/vid_cga.c
@@ -148,6 +148,7 @@ void cga_poll(void *p)
                         if (cga->displine < cga->firstline)
                         {
                                 cga->firstline = cga->displine;
+                                video_wait_for_buffer();
 //                                printf("Firstline %i\n",firstline);
                         }
                         cga->lastline = cga->displine;
diff --git a/src/vid_ega.c b/src/vid_ega.c
index 57880b5..61101eb 100644
--- a/src/vid_ega.c
+++ b/src/vid_ega.c
@@ -271,7 +271,10 @@ void ega_poll(void *p)
                 if (ega->dispon)
                 {
                         if (ega->firstline == 2000) 
+                        {
                                 ega->firstline = ega->displine;
+                                video_wait_for_buffer();
+                        }
 
                         if (ega->scrblank)
                         {
diff --git a/src/vid_hercules.c b/src/vid_hercules.c
index b9832f0..eb80b38 100644
--- a/src/vid_hercules.c
+++ b/src/vid_hercules.c
@@ -139,6 +139,7 @@ void hercules_poll(void *p)
                         if (hercules->displine < hercules->firstline)
                         {
                                 hercules->firstline = hercules->displine;
+                                video_wait_for_buffer();
                         }
                         hercules->lastline = hercules->displine;
                         cols[0] = 0;
diff --git a/src/vid_incolor.c b/src/vid_incolor.c
index c7e2e5b..722bfe5 100644
--- a/src/vid_incolor.c
+++ b/src/vid_incolor.c
@@ -861,6 +861,7 @@ void incolor_poll(void *p)
                         if (incolor->displine < incolor->firstline)
                         {
                                 incolor->firstline = incolor->displine;
+                                video_wait_for_buffer();
                         }
                         incolor->lastline = incolor->displine;
                         if ((incolor->ctrl & INCOLOR_CTRL_GRAPH) && (incolor->ctrl2 & INCOLOR_CTRL2_GRAPH))
diff --git a/src/vid_mda.c b/src/vid_mda.c
index 3897624..5b5befc 100644
--- a/src/vid_mda.c
+++ b/src/vid_mda.c
@@ -123,7 +123,8 @@ void mda_poll(void *p)
                 {
                         if (mda->displine < mda->firstline)
                         {
-                                mda->firstline = mda->displine;
+                                mda->firstline = mda->displine;                                
+                                video_wait_for_buffer();
                         }
                         mda->lastline = mda->displine;
                         cols[0] = 0;
diff --git a/src/vid_pc1512.c b/src/vid_pc1512.c
index 9fd57e4..7f2c506 100644
--- a/src/vid_pc1512.c
+++ b/src/vid_pc1512.c
@@ -179,7 +179,10 @@ static void pc1512_poll(void *p)
                 if (pc1512->dispon)
                 {
                         if (pc1512->displine < pc1512->firstline) 
+                        {
                                 pc1512->firstline = pc1512->displine;
+                                video_wait_for_buffer();
+                        }
                         pc1512->lastline = pc1512->displine;
                         for (c = 0; c < 8; c++)
                         {
diff --git a/src/vid_pcjr.c b/src/vid_pcjr.c
index 0183672..c6eae5f 100644
--- a/src/vid_pcjr.c
+++ b/src/vid_pcjr.c
@@ -217,7 +217,10 @@ void pcjr_poll(void *p)
                         uint16_t mask = 0x1fff;
                         
                         if (pcjr->displine < pcjr->firstline)
-                                pcjr->firstline = pcjr->displine;                                
+                        {
+                                pcjr->firstline = pcjr->displine;
+                                video_wait_for_buffer();
+                        }
                         pcjr->lastline = pcjr->displine;
                         cols[0] = (pcjr->array[2] & 0xf) + 16;
                         for (c = 0; c < 8; c++)
diff --git a/src/vid_svga.c b/src/vid_svga.c
index d691772..9bac226 100644
--- a/src/vid_svga.c
+++ b/src/vid_svga.c
@@ -484,8 +484,11 @@ void svga_poll(void *p)
                         svga->hdisp_on=1;
                         
                         svga->ma &= svga->vrammask;
-                        if (svga->firstline == 2000) 
+                        if (svga->firstline == 2000)
+                        {
                                 svga->firstline = svga->displine;
+                                video_wait_for_buffer();
+                        }
                         
                         if (svga->hwcursor_on || svga->overlay_on)
                                 svga->changedvram[svga->ma >> 12] = svga->changedvram[(svga->ma >> 12) + 1] = 2;
diff --git a/src/vid_tandy.c b/src/vid_tandy.c
index 87b618a..c4b3112 100644
--- a/src/vid_tandy.c
+++ b/src/vid_tandy.c
@@ -236,6 +236,7 @@ void tandy_poll(void *p)
                         if (tandy->displine < tandy->firstline)
                         {
                                 tandy->firstline = tandy->displine;
+                                video_wait_for_buffer();
 //                                printf("Firstline %i\n",firstline);
                         }
                         tandy->lastline = tandy->displine;
diff --git a/src/vid_tandysl.c b/src/vid_tandysl.c
index cacc20b..3843a52 100644
--- a/src/vid_tandysl.c
+++ b/src/vid_tandysl.c
@@ -283,6 +283,7 @@ static void tandysl_poll(void *p)
                         if (tandy->displine < tandy->firstline)
                         {
                                 tandy->firstline = tandy->displine;
+                                video_wait_for_buffer();
 //                                printf("Firstline %i\n",firstline);
                         }
                         tandy->lastline = tandy->displine;
diff --git a/src/vid_voodoo.c b/src/vid_voodoo.c
index 6d83fd3..2b0aa96 100644
--- a/src/vid_voodoo.c
+++ b/src/vid_voodoo.c
@@ -4202,7 +4202,10 @@ void voodoo_callback(void *p)
                                 voodoo->dirty_line[voodoo->line] = 0;
                                 
                                 if (voodoo->line < voodoo->dirty_line_low)
+                                {
                                         voodoo->dirty_line_low = voodoo->line;
+                                        video_wait_for_buffer();
+                                }
                                 if (voodoo->line > voodoo->dirty_line_high)
                                         voodoo->dirty_line_high = voodoo->line;
                                 
diff --git a/src/video.c b/src/video.c
index eac9554..2ee75dc 100644
--- a/src/video.c
+++ b/src/video.c
@@ -9,6 +9,7 @@
 #include "io.h"
 #include "cpu.h"
 #include "rom.h"
+#include "thread.h"
 #include "timer.h"
 
 #include "vid_ati18800.h"
@@ -213,8 +214,8 @@ int video_timing_b, video_timing_w, video_timing_l;
 
 int video_res_x, video_res_y, video_bpp;
 
-void (*video_blit_memtoscreen)(int x, int y, int y1, int y2, int w, int h);
-void (*video_blit_memtoscreen_8)(int x, int y, int w, int h);
+void (*video_blit_memtoscreen_func)(int x, int y, int y1, int y2, int w, int h);
+void (*video_blit_memtoscreen_8_func)(int x, int y, int w, int h);
 
 void video_init()
 {
@@ -359,6 +360,19 @@ void loadfont(char *s, int format)
         fclose(f);
 }
 
+static struct
+{
+        int x, y, y1, y2, w, h, blit8;
+        int busy;
+        int buffer_in_use;
+
+        thread_t *blit_thread;
+        event_t *wake_blit_thread;
+        event_t *blit_complete;
+        event_t *buffer_not_in_use;
+} blit_data;
+
+static void blit_thread(void *param);
 
 void initvideo()
 {
@@ -413,12 +427,85 @@ void initvideo()
         for (c = 0; c < 65536; c++)
                 video_16to32[c] = ((c & 31) << 3) | (((c >> 5) & 63) << 10) | (((c >> 11) & 31) << 19);
 
+        blit_data.wake_blit_thread = thread_create_event();
+        blit_data.blit_complete = thread_create_event();
+        blit_data.buffer_not_in_use = thread_create_event();
+        blit_data.blit_thread = thread_create(blit_thread, NULL);
 }
 
 void closevideo()
 {
+        thread_kill(blit_data.blit_thread);
+        thread_destroy_event(blit_data.buffer_not_in_use);
+        thread_destroy_event(blit_data.blit_complete);
+        thread_destroy_event(blit_data.wake_blit_thread);
+
         free(video_15to32);
         free(video_16to32);
         destroy_bitmap(buffer);
         destroy_bitmap(buffer32);
 }
+
+
+static void blit_thread(void *param)
+{
+        while (1)
+        {
+                thread_wait_event(blit_data.wake_blit_thread, -1);
+                thread_reset_event(blit_data.wake_blit_thread);
+                
+                if (blit_data.blit8)
+                        video_blit_memtoscreen_8_func(blit_data.x, blit_data.y, blit_data.w, blit_data.h);
+                else
+                        video_blit_memtoscreen_func(blit_data.x, blit_data.y, blit_data.y1, blit_data.y2, blit_data.w, blit_data.h);
+                
+                blit_data.busy = 0;
+                thread_set_event(blit_data.blit_complete);
+        }
+}
+
+void video_blit_complete()
+{
+        blit_data.buffer_in_use = 0;
+        thread_set_event(blit_data.buffer_not_in_use);
+}
+
+void video_wait_for_blit()
+{
+        while (blit_data.busy)
+                thread_wait_event(blit_data.blit_complete, -1);
+        thread_reset_event(blit_data.blit_complete);
+}
+void video_wait_for_buffer()
+{
+        while (blit_data.buffer_in_use)
+                thread_wait_event(blit_data.buffer_not_in_use, -1);
+        thread_reset_event(blit_data.buffer_not_in_use);
+}
+
+void video_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
+{
+        video_wait_for_blit();
+        blit_data.busy = 1;
+        blit_data.buffer_in_use = 1;
+        blit_data.x = x;
+        blit_data.y = y;
+        blit_data.y1 = y1;
+        blit_data.y2 = y2;
+        blit_data.w = w;
+        blit_data.h = h;
+        blit_data.blit8 = 0;
+        thread_set_event(blit_data.wake_blit_thread);
+}
+
+void video_blit_memtoscreen_8(int x, int y, int w, int h)
+{
+        video_wait_for_blit();
+        blit_data.busy = 1;
+        blit_data.x = x;
+        blit_data.y = y;
+        blit_data.w = w;
+        blit_data.h = h;
+        blit_data.blit8 = 1;
+        thread_set_event(blit_data.wake_blit_thread);
+}
diff --git a/src/video.h b/src/video.h
index 9183e7d..9c8dd77 100644
--- a/src/video.h
+++ b/src/video.h
@@ -67,8 +67,11 @@ extern int readflash;
 
 extern void (*video_recalctimings)();
 
-extern void (*video_blit_memtoscreen)(int x, int y, int y1, int y2, int w, int h);
-extern void (*video_blit_memtoscreen_8)(int x, int y, int w, int h);
+void video_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h);
+void video_blit_memtoscreen_8(int x, int y, int w, int h);
+
+extern void (*video_blit_memtoscreen_func)(int x, int y, int y1, int y2, int w, int h);
+extern void (*video_blit_memtoscreen_8_func)(int x, int y, int w, int h);
 
 extern int video_timing_b, video_timing_w, video_timing_l;
 extern int video_speed;
@@ -76,3 +79,6 @@ extern int video_speed;
 extern int video_res_x, video_res_y, video_bpp;
 
 extern int vid_resize;
+
+void video_wait_for_blit();
+void video_wait_for_buffer();
diff --git a/src/win-d3d-fs.cc b/src/win-d3d-fs.cc
index 4005cb5..9eeae57 100644
--- a/src/win-d3d-fs.cc
+++ b/src/win-d3d-fs.cc
@@ -17,6 +17,8 @@ static void d3d_fs_close_objects();
 static void d3d_fs_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h);
 static void d3d_fs_blit_memtoscreen_8(int x, int y, int w, int h);
 
+extern "C" void video_blit_complete();
+
 static LPDIRECT3D9             d3d        = NULL;
 static LPDIRECT3DDEVICE9       d3ddev     = NULL; 
 static LPDIRECT3DVERTEXBUFFER9 v_buffer   = NULL;
@@ -120,8 +122,8 @@ void d3d_fs_init(HWND h)
         
         d3d_fs_init_objects();
         
-        video_blit_memtoscreen   = d3d_fs_blit_memtoscreen;
-        video_blit_memtoscreen_8 = d3d_fs_blit_memtoscreen_8;
+        video_blit_memtoscreen_func   = d3d_fs_blit_memtoscreen;
+        video_blit_memtoscreen_8_func = d3d_fs_blit_memtoscreen_8;
 }
 
 static void d3d_fs_close_objects()
@@ -307,7 +309,31 @@ static void d3d_fs_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
         double l, t, r, b;
 
 	if (y1 == y2)
+	{
+                video_blit_complete();
 		return; /*Nothing to do*/
+        }
+
+        if (hr == D3D_OK && !(y1 == 0 && y2 == 0))
+        {
+                RECT lock_rect;
+                
+                lock_rect.top    = y1;
+                lock_rect.left   = 0;
+                lock_rect.bottom = y2;
+                lock_rect.right  = 2047;
+
+                if (FAILED(d3dTexture->LockRect(0, &dr, &lock_rect, 0)))
+                   fatal("LockRect failed\n");
+        
+                for (yy = y1; yy < y2; yy++)
+                        memcpy(dr.pBits + ((yy - y1) * dr.Pitch), &(((uint32_t *)buffer32->line[yy + y])[x]), w * 4);
+
+                video_blit_complete();
+                d3dTexture->UnlockRect(0);
+        }
+        else
+                video_blit_complete();
 
         d3d_verts[0].tu = d3d_verts[2].tu = d3d_verts[3].tu = 0;
         d3d_verts[0].tv = d3d_verts[3].tv = d3d_verts[4].tv = 0;
@@ -337,24 +363,6 @@ static void d3d_fs_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
         if (hr == D3D_OK)
                 hr = v_buffer->Unlock();
 
-        if (hr == D3D_OK && !(y1 == 0 && y2 == 0))
-        {
-                RECT lock_rect;
-                
-                lock_rect.top    = y1;
-                lock_rect.left   = 0;
-                lock_rect.bottom = y2;
-                lock_rect.right  = 2047;
-
-                if (FAILED(d3dTexture->LockRect(0, &dr, &lock_rect, 0)))
-                   fatal("LockRect failed\n");
-        
-                for (yy = y1; yy < y2; yy++)
-                        memcpy(dr.pBits + ((yy - y1) * dr.Pitch), &(((uint32_t *)buffer32->line[yy + y])[x]), w * 4);
-
-                d3dTexture->UnlockRect(0);
-        }
-
         if (hr == D3D_OK)        
                 hr = d3ddev->BeginScene();
 
@@ -400,8 +408,40 @@ static void d3d_fs_blit_memtoscreen_8(int x, int y, int w, int h)
         double l, t, r, b;
 
 	if (!h)
+	{
+                video_blit_complete();
 		return; /*Nothing to do*/
+        }
 
+        if (hr == D3D_OK)
+        {
+                RECT lock_rect;
+                
+                lock_rect.top    = 0;
+                lock_rect.left   = 0;
+                lock_rect.bottom = 2047;
+                lock_rect.right  = 2047;
+
+                if (FAILED(d3dTexture->LockRect(0, &dr, &lock_rect, 0)))
+                        fatal("LockRect failed\n");
+        
+                for (yy = 0; yy < h; yy++)
+                {
+                        uint32_t *p = (uint32_t *)(dr.pBits + (yy * dr.Pitch));
+                        if ((y + yy) >= 0 && (y + yy) < buffer->h)
+                        {
+                                for (xx = 0; xx < w; xx++)
+                                        p[xx] = pal_lookup[buffer->line[y + yy][x + xx]];
+                        }
+                }
+                
+                video_blit_complete();
+
+                d3dTexture->UnlockRect(0);
+        }
+        else
+                video_blit_complete();
+      
         d3d_verts[0].tu = d3d_verts[2].tu = d3d_verts[3].tu = 0;
         d3d_verts[0].tv = d3d_verts[3].tv = d3d_verts[4].tv = 0;
         d3d_verts[1].tu = d3d_verts[4].tu = d3d_verts[5].tu = (float)w / 2048.0;
@@ -430,31 +470,6 @@ static void d3d_fs_blit_memtoscreen_8(int x, int y, int w, int h)
         if (hr == D3D_OK)
                 hr = v_buffer->Unlock();
 
-        if (hr == D3D_OK)
-        {
-                RECT lock_rect;
-                
-                lock_rect.top    = 0;
-                lock_rect.left   = 0;
-                lock_rect.bottom = 2047;
-                lock_rect.right  = 2047;
-
-                if (FAILED(d3dTexture->LockRect(0, &dr, &lock_rect, 0)))
-                        fatal("LockRect failed\n");
-        
-                for (yy = 0; yy < h; yy++)
-                {
-                        uint32_t *p = (uint32_t *)(dr.pBits + (yy * dr.Pitch));
-                        if ((y + yy) >= 0 && (y + yy) < buffer->h)
-                        {
-                                for (xx = 0; xx < w; xx++)
-                                        p[xx] = pal_lookup[buffer->line[y + yy][x + xx]];
-                        }
-                }
-
-                d3dTexture->UnlockRect(0);
-        }
-      
         if (hr == D3D_OK)        
                 hr = d3ddev->BeginScene();
 
diff --git a/src/win-d3d.cc b/src/win-d3d.cc
index d239c2c..c08f887 100644
--- a/src/win-d3d.cc
+++ b/src/win-d3d.cc
@@ -10,6 +10,7 @@ extern "C" void fatal(const char *format, ...);
 extern "C" void pclog(const char *format, ...);
 
 extern "C" void device_force_redraw();
+extern "C" void video_blit_complete();
 
 void d3d_init_objects();
 void d3d_close_objects();
@@ -98,8 +99,8 @@ void d3d_init(HWND h)
         
         d3d_init_objects();
         
-        video_blit_memtoscreen = d3d_blit_memtoscreen;
-        video_blit_memtoscreen_8 = d3d_blit_memtoscreen_8;
+        video_blit_memtoscreen_func = d3d_blit_memtoscreen;
+        video_blit_memtoscreen_8_func = d3d_blit_memtoscreen_8;
 }
 
 void d3d_close_objects()
@@ -231,9 +232,31 @@ void d3d_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
         RECT r;
         uint32_t *p, *src;
         int yy;
-        
+
         if (y1 == y2)
+        {
+                video_blit_complete();
         	return; /*Nothing to do*/
+        }
+
+        r.top    = y1;
+        r.left   = 0;
+        r.bottom = y2;
+        r.right  = 2047;
+
+        if (hr == D3D_OK)
+        {        
+                if (FAILED(d3dTexture->LockRect(0, &dr, &r, 0)))
+                   fatal("LockRect failed\n");
+        
+                for (yy = y1; yy < y2; yy++)
+                        memcpy(dr.pBits + ((yy - y1) * dr.Pitch), &(((uint32_t *)buffer32->line[yy + y])[x]), w * 4);
+
+                video_blit_complete();
+                d3dTexture->UnlockRect(0);
+        }
+        else
+                video_blit_complete();
 
         d3d_verts[0].tu = d3d_verts[2].tu = d3d_verts[3].tu = 0;//0.5 / 2048.0;
         d3d_verts[0].tv = d3d_verts[3].tv = d3d_verts[4].tv = 0;//0.5 / 2048.0;
@@ -253,22 +276,6 @@ void d3d_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
         if (hr == D3D_OK)
                 hr = v_buffer->Unlock();    // unlock the vertex buffer
 
-        r.top    = y1;
-        r.left   = 0;
-        r.bottom = y2;
-        r.right  = 2047;
-
-        if (hr == D3D_OK)
-        {        
-                if (FAILED(d3dTexture->LockRect(0, &dr, &r, 0)))
-                   fatal("LockRect failed\n");
-        
-                for (yy = y1; yy < y2; yy++)
-                        memcpy(dr.pBits + ((yy - y1) * dr.Pitch), &(((uint32_t *)buffer32->line[yy + y])[x]), w * 4);
-
-                d3dTexture->UnlockRect(0);
-        }
-
         if (hr == D3D_OK)        
                 hr = d3ddev->BeginScene();
 
@@ -310,25 +317,10 @@ void d3d_blit_memtoscreen_8(int x, int y, int w, int h)
         HRESULT hr = D3D_OK;
 
 	if (h == 0)
+	{
+                video_blit_complete();
 		return; /*Nothing to do*/
-
-        d3d_verts[0].tu = d3d_verts[2].tu = d3d_verts[3].tu = 0;//0.5 / 2048.0;
-        d3d_verts[0].tv = d3d_verts[3].tv = d3d_verts[4].tv = 0;//0.5 / 2048.0;
-        d3d_verts[1].tu = d3d_verts[4].tu = d3d_verts[5].tu = (float)w / 2048.0;
-        d3d_verts[1].tv = d3d_verts[2].tv = d3d_verts[5].tv = (float)h / 2048.0;
-
-        GetClientRect(d3d_hwnd, &r);
-        d3d_verts[0].x = d3d_verts[2].x = d3d_verts[3].x = -0.5;
-        d3d_verts[0].y = d3d_verts[3].y = d3d_verts[4].y = -0.5;
-        d3d_verts[1].x = d3d_verts[4].x = d3d_verts[5].x = (r.right  - r.left) - 0.5;
-        d3d_verts[1].y = d3d_verts[2].y = d3d_verts[5].y = (r.bottom - r.top) - 0.5;
-
-        if (hr == D3D_OK)
-                hr = v_buffer->Lock(0, 0, (void**)&pVoid, 0);    // lock the vertex buffer
-        if (hr == D3D_OK)
-                memcpy(pVoid, d3d_verts, sizeof(d3d_verts));    // copy the vertices to the locked buffer
-        if (hr == D3D_OK)
-                hr = v_buffer->Unlock();    // unlock the vertex buffer
+        }
 
         r.top    = 0;
         r.left   = 0;
@@ -349,10 +341,31 @@ void d3d_blit_memtoscreen_8(int x, int y, int w, int h)
                                         p[xx] = pal_lookup[buffer->line[y + yy][x + xx]];
                         }
                 }
+                video_blit_complete();
 
                 d3dTexture->UnlockRect(0);
         }
+        else
+                video_blit_complete();
       
+        d3d_verts[0].tu = d3d_verts[2].tu = d3d_verts[3].tu = 0;//0.5 / 2048.0;
+        d3d_verts[0].tv = d3d_verts[3].tv = d3d_verts[4].tv = 0;//0.5 / 2048.0;
+        d3d_verts[1].tu = d3d_verts[4].tu = d3d_verts[5].tu = (float)w / 2048.0;
+        d3d_verts[1].tv = d3d_verts[2].tv = d3d_verts[5].tv = (float)h / 2048.0;
+
+        GetClientRect(d3d_hwnd, &r);
+        d3d_verts[0].x = d3d_verts[2].x = d3d_verts[3].x = -0.5;
+        d3d_verts[0].y = d3d_verts[3].y = d3d_verts[4].y = -0.5;
+        d3d_verts[1].x = d3d_verts[4].x = d3d_verts[5].x = (r.right  - r.left) - 0.5;
+        d3d_verts[1].y = d3d_verts[2].y = d3d_verts[5].y = (r.bottom - r.top) - 0.5;
+
+        if (hr == D3D_OK)
+                hr = v_buffer->Lock(0, 0, (void**)&pVoid, 0);    // lock the vertex buffer
+        if (hr == D3D_OK)
+                memcpy(pVoid, d3d_verts, sizeof(d3d_verts));    // copy the vertices to the locked buffer
+        if (hr == D3D_OK)
+                hr = v_buffer->Unlock();    // unlock the vertex buffer
+
         if (hr == D3D_OK)        
                 hr = d3ddev->BeginScene();
 
diff --git a/src/win-ddraw-fs.cc b/src/win-ddraw-fs.cc
index 4919dd7..993c397 100644
--- a/src/win-ddraw-fs.cc
+++ b/src/win-ddraw-fs.cc
@@ -13,6 +13,8 @@ extern "C" void device_force_redraw();
 extern "C" void ddraw_fs_init(HWND h);
 extern "C" void ddraw_fs_close();
 
+extern "C" void video_blit_complete();
+
 static void ddraw_fs_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h);
 static void ddraw_fs_blit_memtoscreen_8(int x, int y, int w, int h);
 
@@ -105,8 +107,8 @@ void ddraw_fs_init(HWND h)
            
         pclog("DDRAW_INIT complete\n");
         ddraw_hwnd = h;
-        video_blit_memtoscreen   = ddraw_fs_blit_memtoscreen;
-        video_blit_memtoscreen_8 = ddraw_fs_blit_memtoscreen_8;
+        video_blit_memtoscreen_func   = ddraw_fs_blit_memtoscreen;
+        video_blit_memtoscreen_8_func = ddraw_fs_blit_memtoscreen_8;
 }
 
 void ddraw_fs_close()
@@ -207,9 +209,14 @@ static void ddraw_fs_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h
                 lpdds_back->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL);
                 device_force_redraw();
         }
-        if (!ddsd.lpSurface) return;
+        if (!ddsd.lpSurface)
+        {
+                video_blit_complete();
+                return;
+        }
         for (yy = y1; yy < y2; yy++)
             memcpy(ddsd.lpSurface + (yy * ddsd.lPitch), &(((uint32_t *)buffer32->line[y + yy])[x]), w * 4);
+        video_blit_complete();
         lpdds_back->Unlock(NULL);
         
         window_rect.left = 0;
@@ -274,7 +281,11 @@ static void ddraw_fs_blit_memtoscreen_8(int x, int y, int w, int h)
                 lpdds_back->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL);
                 device_force_redraw();
         }
-        if (!ddsd.lpSurface) return;
+        if (!ddsd.lpSurface)
+        {
+                video_blit_complete();
+                return;
+        }
         for (yy = 0; yy < h; yy++)
         {
                 if ((y + yy) >= 0 && (y + yy) < buffer->h)
@@ -284,6 +295,7 @@ static void ddraw_fs_blit_memtoscreen_8(int x, int y, int w, int h)
                             p[xx] = pal_lookup[buffer->line[y + yy][x + xx]];
                 }
         }
+        video_blit_complete();
         lpdds_back->Unlock(NULL);
 
         window_rect.left = 0;
diff --git a/src/win-ddraw.cc b/src/win-ddraw.cc
index 42df38f..c658a7a 100644
--- a/src/win-ddraw.cc
+++ b/src/win-ddraw.cc
@@ -13,6 +13,8 @@ extern "C" void device_force_redraw();
 extern "C" void ddraw_init(HWND h);
 extern "C" void ddraw_close();
 
+extern "C" void video_blit_complete();
+
 static void ddraw_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h);
 static void ddraw_blit_memtoscreen_8(int x, int y, int w, int h);
 
@@ -109,8 +111,8 @@ void ddraw_init(HWND h)
 
         pclog("DDRAW_INIT complete\n");
         ddraw_hwnd = h;
-        video_blit_memtoscreen   = ddraw_blit_memtoscreen;
-        video_blit_memtoscreen_8 = ddraw_blit_memtoscreen_8;
+        video_blit_memtoscreen_func   = ddraw_blit_memtoscreen;
+        video_blit_memtoscreen_8_func = ddraw_blit_memtoscreen_8;
 }
 
 void ddraw_close()
@@ -150,7 +152,6 @@ static void ddraw_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
         POINT po;
         uint32_t *p;
         HRESULT hr;
-        
 //        pclog("Blit memtoscreen %i,%i %i %i %i,%i\n", x, y, y1, y2, w, h);
 
         memset(&ddsd, 0, sizeof(ddsd));
@@ -163,12 +164,17 @@ static void ddraw_blit_memtoscreen(int x, int y, int y1, int y2, int w, int h)
                 lpdds_back->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL);
                 device_force_redraw();
         }
-        if (!ddsd.lpSurface) return;
+        if (!ddsd.lpSurface)
+        {
+                video_blit_complete();
+                return;
+        }
         for (yy = y1; yy < y2; yy++)
         {
                 if ((y + yy) >= 0 && (y + yy) < buffer->h)
                         memcpy(ddsd.lpSurface + (yy * ddsd.lPitch), &(((uint32_t *)buffer32->line[y + yy])[x]), w * 4);
         }
+        video_blit_complete();
         lpdds_back->Unlock(NULL);
 
         po.x = po.y = 0;
@@ -238,7 +244,11 @@ static void ddraw_blit_memtoscreen_8(int x, int y, int w, int h)
                 lpdds_back->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL);
                 device_force_redraw();
         }
-        if (!ddsd.lpSurface) return;
+        if (!ddsd.lpSurface)
+        {
+                video_blit_complete();
+                return;
+        }
         for (yy = 0; yy < h; yy++)
         {
                 if ((y + yy) >= 0 && (y + yy) < buffer->h)
@@ -250,7 +260,8 @@ static void ddraw_blit_memtoscreen_8(int x, int y, int w, int h)
         }
         p = (uint32_t *)(ddsd.lpSurface + (4 * ddsd.lPitch));
         lpdds_back->Unlock(NULL);
-
+        video_blit_complete();
+        
         po.x = po.y = 0;
         
         ClientToScreen(ddraw_hwnd, &po);
diff --git a/src/win.c b/src/win.c
index 8d6c972..8f383a0 100644
--- a/src/win.c
+++ b/src/win.c
@@ -181,6 +181,7 @@ void mainthread(LPVOID param)
                 if (!video_fullscreen && win_doresize)
                 {
                         RECT r;
+                        video_wait_for_blit();
                         GetWindowRect(ghwnd, &r);
                         MoveWindow(ghwnd, r.left, r.top,
                                 winsizex + (GetSystemMetrics(SM_CXFIXEDFRAME) * 2),
@@ -953,6 +954,7 @@ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM
                         
                         case IDM_VID_DDRAW: case IDM_VID_D3D:
                         startblit();
+                        video_wait_for_blit();
                         CheckMenuItem(hmenu, IDM_VID_DDRAW + vid_api, MF_UNCHECKED);
                         vid_apis[0][vid_api].close();
                         vid_api = LOWORD(wParam) - IDM_VID_DDRAW;
@@ -970,6 +972,7 @@ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM
                                 MessageBox(hwnd, "Use CTRL + ALT + PAGE DOWN to return to windowed mode", "PCem", MB_OK);
                         }
                         startblit();
+                        video_wait_for_blit();
                         mouse_close();
                         vid_apis[0][vid_api].close();
                         video_fullscreen = 1;
@@ -1268,6 +1271,7 @@ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM
                 if (vid_apis[video_fullscreen][vid_api].resize)
                 {
                         startblit();
+                        video_wait_for_blit();
                         vid_apis[video_fullscreen][vid_api].resize(winsizex, winsizey);
                         endblit();
                 }