diff --git a/hw/display/Kconfig b/hw/display/Kconfig
index 910dccb2f7..cbdf7b1a67 100644
--- a/hw/display/Kconfig
+++ b/hw/display/Kconfig
@@ -130,3 +130,5 @@ config ATI_VGA
     default y if PCI_DEVICES
     depends on PCI
     select VGA
+    select BITBANG_I2C
+    select DDC
diff --git a/hw/display/ati.c b/hw/display/ati.c
index 76595d9511..0cb1173848 100644
--- a/hw/display/ati.c
+++ b/hw/display/ati.c
@@ -26,6 +26,7 @@
 #include "qapi/error.h"
 #include "hw/hw.h"
 #include "ui/console.h"
+#include "hw/display/i2c-ddc.h"
 #include "trace.h"
 
 #define ATI_DEBUG_HW_CURSOR 0
@@ -215,6 +216,24 @@ static void ati_cursor_draw_line(VGACommonState *vga, uint8_t *d, int scr_y)
     }
 }
 
+static uint64_t ati_i2c(bitbang_i2c_interface *i2c, uint64_t data, int base)
+{
+    bool c = (data & BIT(base + 17) ? !!(data & BIT(base + 1)) : 1);
+    bool d = (data & BIT(base + 16) ? !!(data & BIT(base)) : 1);
+
+    bitbang_i2c_set(i2c, BITBANG_I2C_SCL, c);
+    d = bitbang_i2c_set(i2c, BITBANG_I2C_SDA, d);
+
+    data &= ~0xf00ULL;
+    if (c) {
+        data |= BIT(base + 9);
+    }
+    if (d) {
+        data |= BIT(base + 8);
+    }
+    return data;
+}
+
 static inline uint64_t ati_reg_read_offs(uint32_t reg, int offs,
                                          unsigned int size)
 {
@@ -266,7 +285,16 @@ static uint64_t ati_mm_read(void *opaque, hwaddr addr, unsigned int size)
     case DAC_CNTL:
         val = s->regs.dac_cntl;
         break;
-/*    case GPIO_MONID: FIXME hook up DDC I2C here */
+    case GPIO_VGA_DDC:
+        val = s->regs.gpio_vga_ddc;
+        break;
+    case GPIO_DVI_DDC:
+        val = s->regs.gpio_dvi_ddc;
+        break;
+    case GPIO_MONID ... GPIO_MONID + 3:
+        val = ati_reg_read_offs(s->regs.gpio_monid,
+                                addr - GPIO_MONID, size);
+        break;
     case PALETTE_INDEX:
         /* FIXME unaligned access */
         val = vga_ioport_read(&s->vga, VGA_PEL_IR) << 16;
@@ -391,9 +419,15 @@ static uint64_t ati_mm_read(void *opaque, hwaddr addr, unsigned int size)
         break;
     case DEFAULT_OFFSET:
         val = s->regs.default_offset;
+        if (s->dev_id != PCI_DEVICE_ID_ATI_RAGE128_PF) {
+            val >>= 10;
+            val |= s->regs.default_pitch << 16;
+            val |= s->regs.default_tile << 30;
+        }
         break;
     case DEFAULT_PITCH:
         val = s->regs.default_pitch;
+        val |= s->regs.default_tile << 16;
         break;
     case DEFAULT_SC_BOTTOM_RIGHT:
         val = s->regs.default_sc_bottom_right;
@@ -497,7 +531,33 @@ static void ati_mm_write(void *opaque, hwaddr addr,
         s->regs.dac_cntl = data & 0xffffe3ff;
         s->vga.dac_8bit = !!(data & DAC_8BIT_EN);
         break;
-/*    case GPIO_MONID: FIXME hook up DDC I2C here */
+    case GPIO_VGA_DDC:
+        if (s->dev_id != PCI_DEVICE_ID_ATI_RAGE128_PF) {
+            /* FIXME: Maybe add a property to select VGA or DVI port? */
+        }
+        break;
+    case GPIO_DVI_DDC:
+        if (s->dev_id != PCI_DEVICE_ID_ATI_RAGE128_PF) {
+            s->regs.gpio_dvi_ddc = ati_i2c(s->bbi2c, data, 0);
+        }
+        break;
+    case GPIO_MONID ... GPIO_MONID + 3:
+        /* FIXME What does Radeon have here? */
+        if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
+            ati_reg_write_offs(&s->regs.gpio_monid,
+                               addr - GPIO_MONID, data, size);
+            /*
+             * Rage128p accesses DDC used to get EDID via these bits.
+             * Only touch i2c when write overlaps 3rd byte because some
+             * drivers access this reg via multiple partial writes and
+             * without this spurious bits would be sent.
+             */
+            if ((s->regs.gpio_monid & BIT(25)) &&
+                addr <= GPIO_MONID + 2 && addr + size > GPIO_MONID + 2) {
+                s->regs.gpio_monid = ati_i2c(s->bbi2c, s->regs.gpio_monid, 1);
+            }
+        }
+        break;
     case PALETTE_INDEX ... PALETTE_INDEX + 3:
         if (size == 4) {
             vga_ioport_write(&s->vga, VGA_PEL_IR, (data >> 16) & 0xff);
@@ -628,22 +688,22 @@ static void ati_mm_write(void *opaque, hwaddr addr,
         break;
     case SRC_PITCH_OFFSET:
         if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
-            s->regs.src_offset = (data & 0x1fffff) << 5;
-            s->regs.src_pitch = (data >> 21) & 0x3ff;
+            s->regs.src_offset = (data & 0x1fffff) << 4;
+            s->regs.src_pitch = (data & 0x7fe00000) >> 21;
             s->regs.src_tile = data >> 31;
         } else {
-            s->regs.src_offset = (data & 0x3fffff) << 11;
+            s->regs.src_offset = (data & 0x3fffff) << 10;
             s->regs.src_pitch = (data & 0x3fc00000) >> 16;
             s->regs.src_tile = (data >> 30) & 1;
         }
         break;
     case DST_PITCH_OFFSET:
         if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
-            s->regs.dst_offset = (data & 0x1fffff) << 5;
-            s->regs.dst_pitch = (data >> 21) & 0x3ff;
+            s->regs.dst_offset = (data & 0x1fffff) << 4;
+            s->regs.dst_pitch = (data & 0x7fe00000) >> 21;
             s->regs.dst_tile = data >> 31;
         } else {
-            s->regs.dst_offset = (data & 0x3fffff) << 11;
+            s->regs.dst_offset = (data & 0x3fffff) << 10;
             s->regs.dst_pitch = (data & 0x3fc00000) >> 16;
             s->regs.dst_tile = data >> 30;
         }
@@ -723,13 +783,19 @@ static void ati_mm_write(void *opaque, hwaddr addr,
         s->regs.dp_write_mask = data;
         break;
     case DEFAULT_OFFSET:
-        data &= (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF ?
-                 0x03fffc00 : 0xfffffc00);
-        s->regs.default_offset = data;
+        if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
+            s->regs.default_offset = data & 0xfffffff0;
+        } else {
+            /* Radeon has DEFAULT_PITCH_OFFSET here like DST_PITCH_OFFSET */
+            s->regs.default_offset = (data & 0x3fffff) << 10;
+            s->regs.default_pitch = (data & 0x3fc00000) >> 16;
+            s->regs.default_tile = data >> 30;
+        }
         break;
     case DEFAULT_PITCH:
         if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
-            s->regs.default_pitch = data & 0x103ff;
+            s->regs.default_pitch = data & 0x3fff;
+            s->regs.default_tile = (data >> 16) & 1;
         }
         break;
     case DEFAULT_SC_BOTTOM_RIGHT:
@@ -788,6 +854,12 @@ static void ati_vga_realize(PCIDevice *dev, Error **errp)
         vga->cursor_draw_line = ati_cursor_draw_line;
     }
 
+    /* ddc, edid */
+    I2CBus *i2cbus = i2c_init_bus(DEVICE(s), "ati-vga.ddc");
+    s->bbi2c = bitbang_i2c_init(i2cbus);
+    I2CSlave *i2cddc = I2C_SLAVE(qdev_create(BUS(i2cbus), TYPE_I2CDDC));
+    i2c_set_slave_address(i2cddc, 0x50);
+
     /* mmio register space */
     memory_region_init_io(&s->mm, OBJECT(s), &ati_mm_ops, s,
                           "ati.mmregs", 0x4000);
@@ -813,6 +885,7 @@ static void ati_vga_exit(PCIDevice *dev)
     ATIVGAState *s = ATI_VGA(dev);
 
     graphic_console_close(s->vga.con);
+    g_free(s->bbi2c);
 }
 
 static Property ati_vga_properties[] = {
@@ -837,7 +910,7 @@ static void ati_vga_class_init(ObjectClass *klass, void *data)
     k->class_id = PCI_CLASS_DISPLAY_VGA;
     k->vendor_id = PCI_VENDOR_ID_ATI;
     k->device_id = PCI_DEVICE_ID_ATI_RAGE128_PF;
-    k->romfile = "vgabios-stdvga.bin";
+    k->romfile = "vgabios-ati.bin";
     k->realize = ati_vga_realize;
     k->exit = ati_vga_exit;
 }
diff --git a/hw/display/ati_2d.c b/hw/display/ati_2d.c
index d83c29c6d9..2dbf53f039 100644
--- a/hw/display/ati_2d.c
+++ b/hw/display/ati_2d.c
@@ -51,8 +51,9 @@ void ati_2d_blt(ATIVGAState *s)
             s->vga.vbe_start_addr, surface_data(ds), surface_stride(ds),
             surface_bits_per_pixel(ds),
             (s->regs.dp_mix & GMC_ROP3_MASK) >> 16);
-    DPRINTF("%d %d, %d %d, (%d,%d) -> (%d,%d) %dx%d\n", s->regs.src_offset,
-            s->regs.dst_offset, s->regs.src_pitch, s->regs.dst_pitch,
+    DPRINTF("%d %d %d, %d %d %d, (%d,%d) -> (%d,%d) %dx%d\n",
+            s->regs.src_offset, s->regs.dst_offset, s->regs.default_offset,
+            s->regs.src_pitch, s->regs.dst_pitch, s->regs.default_pitch,
             s->regs.src_x, s->regs.src_y, s->regs.dst_x, s->regs.dst_y,
             s->regs.dst_width, s->regs.dst_height);
     switch (s->regs.dp_mix & GMC_ROP3_MASK) {
@@ -60,10 +61,16 @@ void ati_2d_blt(ATIVGAState *s)
     {
         uint8_t *src_bits, *dst_bits, *end;
         int src_stride, dst_stride, bpp = ati_bpp_from_datatype(s);
-        src_bits = s->vga.vram_ptr + s->regs.src_offset;
-        dst_bits = s->vga.vram_ptr + s->regs.dst_offset;
-        src_stride = s->regs.src_pitch;
-        dst_stride = s->regs.dst_pitch;
+        src_bits = s->vga.vram_ptr +
+                   (s->regs.dp_gui_master_cntl & GMC_SRC_PITCH_OFFSET_CNTL ?
+                    s->regs.src_offset : s->regs.default_offset);
+        dst_bits = s->vga.vram_ptr +
+                   (s->regs.dp_gui_master_cntl & GMC_DST_PITCH_OFFSET_CNTL ?
+                    s->regs.dst_offset : s->regs.default_offset);
+        src_stride = (s->regs.dp_gui_master_cntl & GMC_SRC_PITCH_OFFSET_CNTL ?
+                      s->regs.src_pitch : s->regs.default_pitch);
+        dst_stride = (s->regs.dp_gui_master_cntl & GMC_DST_PITCH_OFFSET_CNTL ?
+                      s->regs.dst_pitch : s->regs.default_pitch);
 
         if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
             src_bits += s->regs.crtc_offset & 0x07ffffff;
@@ -111,8 +118,11 @@ void ati_2d_blt(ATIVGAState *s)
         uint8_t *dst_bits, *end;
         int dst_stride, bpp = ati_bpp_from_datatype(s);
         uint32_t filler = 0;
-        dst_bits = s->vga.vram_ptr + s->regs.dst_offset;
-        dst_stride = s->regs.dst_pitch;
+        dst_bits = s->vga.vram_ptr +
+                   (s->regs.dp_gui_master_cntl & GMC_DST_PITCH_OFFSET_CNTL ?
+                    s->regs.dst_offset : s->regs.default_offset);
+        dst_stride = (s->regs.dp_gui_master_cntl & GMC_DST_PITCH_OFFSET_CNTL ?
+                      s->regs.dst_pitch : s->regs.default_pitch);
 
         if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
             dst_bits += s->regs.crtc_offset & 0x07ffffff;
diff --git a/hw/display/ati_dbg.c b/hw/display/ati_dbg.c
index b045f81d06..88b3a11315 100644
--- a/hw/display/ati_dbg.c
+++ b/hw/display/ati_dbg.c
@@ -19,6 +19,8 @@ static struct ati_regdesc ati_reg_names[] = {
     {"CRTC_GEN_CNTL", 0x0050},
     {"CRTC_EXT_CNTL", 0x0054},
     {"DAC_CNTL", 0x0058},
+    {"GPIO_VGA_DDC", 0x0060},
+    {"GPIO_DVI_DDC", 0x0064},
     {"GPIO_MONID", 0x0068},
     {"I2C_CNTL_1", 0x0094},
     {"PALETTE_INDEX", 0x00b0},
diff --git a/hw/display/ati_int.h b/hw/display/ati_int.h
index 2f426064cf..9b67d0022a 100644
--- a/hw/display/ati_int.h
+++ b/hw/display/ati_int.h
@@ -10,6 +10,7 @@
 #define ATI_INT_H
 
 #include "hw/pci/pci.h"
+#include "hw/i2c/bitbang_i2c.h"
 #include "vga_int.h"
 
 /*#define DEBUG_ATI*/
@@ -35,6 +36,9 @@ typedef struct ATIVGARegs {
     uint32_t crtc_gen_cntl;
     uint32_t crtc_ext_cntl;
     uint32_t dac_cntl;
+    uint32_t gpio_vga_ddc;
+    uint32_t gpio_dvi_ddc;
+    uint32_t gpio_monid;
     uint32_t crtc_h_total_disp;
     uint32_t crtc_h_sync_strt_wid;
     uint32_t crtc_v_total_disp;
@@ -70,6 +74,7 @@ typedef struct ATIVGARegs {
     uint32_t dp_write_mask;
     uint32_t default_offset;
     uint32_t default_pitch;
+    uint32_t default_tile;
     uint32_t default_sc_bottom_right;
 } ATIVGARegs;
 
@@ -83,6 +88,7 @@ typedef struct ATIVGAState {
     uint16_t cursor_size;
     uint32_t cursor_offset;
     QEMUCursor *cursor;
+    bitbang_i2c_interface *bbi2c;
     MemoryRegion io;
     MemoryRegion mm;
     ATIVGARegs regs;
diff --git a/hw/display/ati_regs.h b/hw/display/ati_regs.h
index 923bfd33ce..d7155c93d5 100644
--- a/hw/display/ati_regs.h
+++ b/hw/display/ati_regs.h
@@ -37,6 +37,8 @@
 #define CRTC_GEN_CNTL                           0x0050
 #define CRTC_EXT_CNTL                           0x0054
 #define DAC_CNTL                                0x0058
+#define GPIO_VGA_DDC                            0x0060
+#define GPIO_DVI_DDC                            0x0064
 #define GPIO_MONID                              0x0068
 #define I2C_CNTL_1                              0x0094
 #define PALETTE_INDEX                           0x00b0
@@ -368,8 +370,8 @@
 #define BRUSH_SOLIDCOLOR                        0x00000d00
 
 /* DP_GUI_MASTER_CNTL bit constants */
-#define GMC_SRC_PITCH_OFFSET_DEFAULT            0x00000000
-#define GMC_DST_PITCH_OFFSET_DEFAULT            0x00000000
+#define GMC_SRC_PITCH_OFFSET_CNTL               0x00000001
+#define GMC_DST_PITCH_OFFSET_CNTL               0x00000002
 #define GMC_SRC_CLIP_DEFAULT                    0x00000000
 #define GMC_DST_CLIP_DEFAULT                    0x00000000
 #define GMC_BRUSH_SOLIDCOLOR                    0x000000d0
diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index 5dfc72d9d7..3cb0509b02 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -12,7 +12,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/hw.h"
-#include "bitbang_i2c.h"
+#include "hw/i2c/bitbang_i2c.h"
 #include "hw/sysbus.h"
 #include "qemu/module.h"
 
diff --git a/hw/i2c/ppc4xx_i2c.c b/hw/i2c/ppc4xx_i2c.c
index d606d3dbeb..5fb4f86c38 100644
--- a/hw/i2c/ppc4xx_i2c.c
+++ b/hw/i2c/ppc4xx_i2c.c
@@ -30,7 +30,6 @@
 #include "cpu.h"
 #include "hw/hw.h"
 #include "hw/i2c/ppc4xx_i2c.h"
-#include "bitbang_i2c.h"
 
 #define PPC4xx_I2C_MEM_SIZE 18
 
diff --git a/hw/i2c/versatile_i2c.c b/hw/i2c/versatile_i2c.c
index e07be9890c..24b6e36b6d 100644
--- a/hw/i2c/versatile_i2c.c
+++ b/hw/i2c/versatile_i2c.c
@@ -23,7 +23,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/sysbus.h"
-#include "bitbang_i2c.h"
+#include "hw/i2c/bitbang_i2c.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 
diff --git a/hw/i2c/bitbang_i2c.h b/include/hw/i2c/bitbang_i2c.h
similarity index 80%
rename from hw/i2c/bitbang_i2c.h
rename to include/hw/i2c/bitbang_i2c.h
index 9443021710..3a7126d5de 100644
--- a/hw/i2c/bitbang_i2c.h
+++ b/include/hw/i2c/bitbang_i2c.h
@@ -3,6 +3,8 @@
 
 #include "hw/i2c/i2c.h"
 
+typedef struct bitbang_i2c_interface bitbang_i2c_interface;
+
 #define BITBANG_I2C_SDA 0
 #define BITBANG_I2C_SCL 1
 
diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h
index 8e236f7bb4..75c5bd638b 100644
--- a/include/hw/i2c/i2c.h
+++ b/include/hw/i2c/i2c.h
@@ -81,8 +81,6 @@ uint8_t i2c_recv(I2CBus *bus);
 
 DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr);
 
-typedef struct bitbang_i2c_interface bitbang_i2c_interface;
-
 /* lm832x.c */
 void lm832x_key_event(DeviceState *dev, int key, int state);
 
diff --git a/include/hw/i2c/ppc4xx_i2c.h b/include/hw/i2c/ppc4xx_i2c.h
index aa2a2bf9de..8437bf070b 100644
--- a/include/hw/i2c/ppc4xx_i2c.h
+++ b/include/hw/i2c/ppc4xx_i2c.h
@@ -28,7 +28,7 @@
 #define PPC4XX_I2C_H
 
 #include "hw/sysbus.h"
-#include "hw/i2c/i2c.h"
+#include "hw/i2c/bitbang_i2c.h"
 
 #define TYPE_PPC4xx_I2C "ppc4xx-i2c"
 #define PPC4xx_I2C(obj) OBJECT_CHECK(PPC4xxI2CState, (obj), TYPE_PPC4xx_I2C)
diff --git a/pc-bios/vgabios-ati.bin b/pc-bios/vgabios-ati.bin
new file mode 100644
index 0000000000..79644708ff
Binary files /dev/null and b/pc-bios/vgabios-ati.bin differ
diff --git a/roms/config.vga-ati b/roms/config.vga-ati
new file mode 100644
index 0000000000..12506b6644
--- /dev/null
+++ b/roms/config.vga-ati
@@ -0,0 +1,4 @@
+CONFIG_QEMU=y
+CONFIG_BUILD_VGABIOS=y
+CONFIG_VGA_ATI=y
+CONFIG_VGA_PCI=y