diff --git a/src/ibm.h b/src/ibm.h
index 4212fad..e59b322 100644
--- a/src/ibm.h
+++ b/src/ibm.h
@@ -300,6 +300,7 @@ enum
 	GFX_SIGMA400,	/*Sigma Designs Color 400 */
 	GFX_PGC,	/*Professional Graphics Controller */
 	GFX_IM1024,	/*Vermont Microsystems IM1024 */
+	GFX_EGAWONDER800, /*ATI EGA Wonder 800+*/
         GFX_MAX
 };
 
diff --git a/src/vid_ati18800.c b/src/vid_ati18800.c
index 7e672a0..fd00caa 100644
--- a/src/vid_ati18800.c
+++ b/src/vid_ati18800.c
@@ -19,6 +19,10 @@ typedef struct ati18800_t
         
         uint8_t regs[256];
         int index;
+        
+        int is_ega;
+        int ega_switches;
+        int ega_switch_read;
 } ati18800_t;
 
 void ati18800_out(uint16_t addr, uint8_t val, void *p)
@@ -56,6 +60,43 @@ void ati18800_out(uint16_t addr, uint8_t val, void *p)
                 }
                 break;
                 
+                case 0x3c2:
+                if (ati18800->is_ega)
+                {
+                        if ((val & 0x80) != (svga->miscout & 0x80))
+                        {
+                                int c;
+                                
+                                if (val & 0x80)
+                                {
+                                        for (c = 0; c < 256; c++)
+                                        {
+                                                ati18800->svga.pallook[c]  = makecol32(((c >> 2) & 1) * 0xaa, ((c >> 1) & 1) * 0xaa, (c & 1) * 0xaa);
+                                                ati18800->svga.pallook[c] += makecol32(((c >> 5) & 1) * 0x55, ((c >> 4) & 1) * 0x55, ((c >> 3) & 1) * 0x55);
+                                        }
+                                        ati18800->svga.vertical_linedbl = 0;
+                                }
+                                else
+                                {
+                                        for (c = 0; c < 256; c++)
+                                        {
+                                                if ((c & 0x17) == 6)
+                                                        ati18800->svga.pallook[c]  = makecol32(0xaa, 0x55, 0x00);
+                                                else
+                                                {
+                                                        ati18800->svga.pallook[c]  = makecol32(((c >> 2) & 1) * 0xaa, ((c >> 1) & 1) * 0xaa, (c & 1) * 0xaa);
+                                                        ati18800->svga.pallook[c] += makecol32(((c >> 4) & 1) * 0x55, ((c >> 4) & 1) * 0x55, ((c >> 4) & 1) * 0x55);
+                                                }
+                                        }
+                                        ati18800->svga.vertical_linedbl = 1;
+                                }
+                                
+                                svga->fullchange = changeframecount;
+                        }
+                        ati18800->ega_switch_read = val & 0xc;
+                }
+                break;
+
                 case 0x3D4:
                 svga->crtcreg = val & 0x3f;
                 return;
@@ -109,6 +150,20 @@ uint8_t ati18800_in(uint16_t addr, void *p)
                 }
                 break;
 
+                case 0x3c2:
+                if (ati18800->is_ega)
+                {
+                        switch (ati18800->ega_switch_read)
+                        {
+                                case 0xc: return (ati18800->ega_switches & 1) ? 0x10 : 0;
+                                case 0x8: return (ati18800->ega_switches & 2) ? 0x10 : 0;
+                                case 0x4: return (ati18800->ega_switches & 4) ? 0x10 : 0;
+                                case 0x0: return (ati18800->ega_switches & 8) ? 0x10 : 0;
+                        }
+                }
+                break;
+
+
                 case 0x3D4:
                 temp = svga->crtcreg;
                 break;
@@ -119,10 +174,25 @@ uint8_t ati18800_in(uint16_t addr, void *p)
                 temp = svga_in(addr, svga);
                 break;
         }
-        if (addr != 0x3da) pclog("%02X  %04X:%04X\n", temp, CS,cpu_state.pc);
+//        if (addr != 0x3da) pclog("%02X  %04X:%04X\n", temp, CS,cpu_state.pc);
         return temp;
 }
 
+static void ega_wonder_800_recalctimings(svga_t *svga)
+{
+        ati18800_t *ati18800 = (ati18800_t *)svga->p;
+        int clksel = ((svga->miscout & 0xc) >> 2) | ((ati18800->regs[0xbe] & 0x10) ? 4 : 0);
+
+        switch (clksel)
+        {
+                case 0: svga->clock = (cpuclock * (double)(1ull << 32)) / 25175000.0; break;
+                case 1: svga->clock = (cpuclock * (double)(1ull << 32)) / 28322000.0; break;
+                case 4: svga->clock = (cpuclock * (double)(1ull << 32)) / 14318181.0; break;
+                case 5: svga->clock = (cpuclock * (double)(1ull << 32)) / 16257000.0; break;
+                case 7: default: svga->clock = (cpuclock * (double)(1ull << 32)) / 36000000.0; break;
+        }
+}
+
 void *ati18800_init()
 {
         ati18800_t *ati18800 = malloc(sizeof(ati18800_t));
@@ -146,11 +216,51 @@ void *ati18800_init()
         return ati18800;
 }
 
+void *ega_wonder_800_init()
+{
+        int c;
+        
+        ati18800_t *ati18800 = malloc(sizeof(ati18800_t));
+        memset(ati18800, 0, sizeof(ati18800_t));
+        
+        rom_init(&ati18800->bios_rom, "ATI EGA Wonder 800+ N1.00.BIN", 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);
+        
+        svga_init(&ati18800->svga, ati18800, 1 << 18, /*256kb*/
+                   ega_wonder_800_recalctimings,
+                   ati18800_in, ati18800_out,
+                   NULL,
+                   NULL);
+
+        io_sethandler(0x01ce, 0x0002, ati18800_in, NULL, NULL, ati18800_out, NULL, NULL, ati18800);
+        io_sethandler(0x03c0, 0x0006, ati18800_in, NULL, NULL, ati18800_out, NULL, NULL, ati18800);
+        io_sethandler(0x03ca, 0x0016, ati18800_in, NULL, NULL, ati18800_out, NULL, NULL, ati18800);
+
+        ati18800->svga.miscout = 1;
+
+        for (c = 0; c < 256; c++)
+        {
+                ati18800->svga.pallook[c]  = makecol32(((c >> 2) & 1) * 0xaa, ((c >> 1) & 1) * 0xaa, (c & 1) * 0xaa);
+                ati18800->svga.pallook[c] += makecol32(((c >> 5) & 1) * 0x55, ((c >> 4) & 1) * 0x55, ((c >> 3) & 1) * 0x55);
+        }
+
+        ati_eeprom_load(&ati18800->eeprom, "egawonder800.nvr", 0);
+        
+        ati18800->is_ega = 1;
+        ati18800->ega_switches = 9;
+
+        return ati18800;
+}
+
 static int ati18800_available()
 {
         return rom_present("vgaedge16.vbi");
 }
 
+static int ega_wonder_800_available()
+{
+        return rom_present("ATI EGA Wonder 800+ N1.00.BIN");
+}
+
 void ati18800_close(void *p)
 {
         ati18800_t *ati18800 = (ati18800_t *)p;
@@ -193,3 +303,14 @@ device_t ati18800_device =
         ati18800_add_status_info
 };
 
+device_t ati_ega_wonder_800_device =
+{
+        "ATI EGA Wonder 800+",
+        0,
+        ega_wonder_800_init,
+        ati18800_close,
+        ega_wonder_800_available,
+        ati18800_speed_changed,
+        ati18800_force_redraw,
+        ati18800_add_status_info
+};
diff --git a/src/vid_ati18800.h b/src/vid_ati18800.h
index 83fe2c0..0d667ab 100644
--- a/src/vid_ati18800.h
+++ b/src/vid_ati18800.h
@@ -1 +1,2 @@
 extern device_t ati18800_device;
+extern device_t ati_ega_wonder_800_device;
diff --git a/src/vid_ati_eeprom.c b/src/vid_ati_eeprom.c
index 3586894..ce13701 100644
--- a/src/vid_ati_eeprom.c
+++ b/src/vid_ati_eeprom.c
@@ -37,7 +37,7 @@ void ati_eeprom_load(ati_eeprom_t *eeprom, char *fn, int type)
         f = nvrfopen(eeprom->fn, "rb");
         if (!f)
         {
-                memset(eeprom->data, 0, eeprom->type ? 512 : 128);
+                memset(eeprom->data, 0xff, eeprom->type ? 512 : 128);
                 return;
         }
         fread(eeprom->data, 1, eeprom->type ? 512 : 128, f);
diff --git a/src/vid_svga.c b/src/vid_svga.c
index 538b131..3418ae1 100644
--- a/src/vid_svga.c
+++ b/src/vid_svga.c
@@ -582,6 +582,11 @@ void svga_poll(void *p)
                                 svga->ma = svga->maback;
                         }
                 }
+                svga->hsync_divisor = !svga->hsync_divisor;
+                
+                if (svga->hsync_divisor && (svga->crtc[0x17] & 4))
+                        return;
+
                 svga->vc++;
                 svga->vc &= 2047;
 
@@ -1296,7 +1301,10 @@ void svga_doblit(int y1, int y2, int wx, int wy, svga_t *svga)
                 if (xsize<64) xsize=656;
                 if (ysize<32) ysize=200;
 
-                updatewindowsize(xsize,ysize);
+                if (svga->vertical_linedbl)
+                        updatewindowsize(xsize,ysize*2);
+                else
+                        updatewindowsize(xsize,ysize);
         }
         if (vid_resize)
         {
diff --git a/src/vid_svga.h b/src/vid_svga.h
index 08f5111..5a7efa3 100644
--- a/src/vid_svga.h
+++ b/src/vid_svga.h
@@ -129,6 +129,11 @@ typedef struct svga_t
         void *p;
 
         uint8_t ksc5601_sbyte_mask;
+        
+        int vertical_linedbl;
+        
+        /*Used to implement CRTC[0x17] bit 2 hsync divisor*/
+        int hsync_divisor;
 } svga_t;
 
 extern int svga_init(svga_t *svga, void *p, int memsize, 
diff --git a/src/video.c b/src/video.c
index 7eb151d..3b31973 100644
--- a/src/video.c
+++ b/src/video.c
@@ -83,6 +83,7 @@ static VIDEO_CARD video_cards[] =
 {
         {"ATI Graphics Pro Turbo (Mach64 GX)",     "mach64gx",       &mach64gx_device,                  GFX_MACH64GX,        VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_BUS, 2,  2,  1,  20, 20, 21}},
         {"ATI Video Xpression (Mach64 VT2)",       "mach64vt2",      &mach64vt2_device,                 GFX_MACH64VT2,       VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_BUS, 2,  2,  1,  20, 20, 21}},
+        {"ATI EGA Wonder 800+ (ATI-18800)",        "egawonder800",   &ati_ega_wonder_800_device,        GFX_EGAWONDER800,    VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_ISA, 8, 16, 32,   8, 16, 32}},
         {"ATI Korean VGA (ATI-28800)",             "ati28800k",      &ati28800k_device,                 GFX_ATIKOREANVGA,    VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_ISA, 3,  3,  6,   5,  5, 10}},
         {"ATI VGA Charger (ATI-28800)",            "ati28800",       &ati28800_device,                  GFX_VGACHARGER,      VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_ISA, 3,  3,  6,   5,  5, 10}},
         {"ATI VGA Edge-16 (ATI-18800)",            "ati18800",       &ati18800_device,                  GFX_VGAEDGE16,       VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_ISA, 8, 16, 32,   8, 16, 32}},