diff --git a/src/device/mouse.c b/src/device/mouse.c
index 46ecceec1..7a90e2c3f 100644
--- a/src/device/mouse.c
+++ b/src/device/mouse.c
@@ -32,6 +32,8 @@
 #include <86box/timer.h>
 #include <86box/gdbstub.h>
 #include <86box/mouse.h>
+#include <86box/video.h>
+#include <86box/plat.h>
 #include <86box/plat_unused.h>
 
 typedef struct mouse_t {
@@ -43,6 +45,8 @@ atomic_int mouse_x;
 atomic_int mouse_y;
 atomic_int mouse_z;
 atomic_int mouse_buttons;
+atomic_int old_mouse_x;
+atomic_int old_mouse_y;
 int mouse_mode;
 int mouse_timed = 1;
 int mouse_tablet_in_proximity = 0;
@@ -52,8 +56,10 @@ double mouse_x_abs;
 double mouse_y_abs;
 
 double mouse_sensitivity = 1.0;
-double mouse_x_error = 0.0;
-double mouse_y_error = 0.0;
+_Atomic double mouse_x_error = 0.0;
+_Atomic double mouse_y_error = 0.0;
+_Atomic double mouse_x_raw = 0.0;
+_Atomic double mouse_y_raw = 0.0;
 
 pc_timer_t mouse_timer; /* mouse event timer */
 
@@ -130,12 +136,21 @@ mouse_log(const char *fmt, ...)
 #    define mouse_log(fmt, ...)
 #endif
 
+void
+mouse_clear_coords(void)
+{
+    mouse_x = mouse_y = mouse_z = 0;
+    old_mouse_x = old_mouse_y = 0;
+    mouse_x_error = mouse_y_error = 0.0;
+    mouse_x_raw = mouse_y_raw = 0.0;
+}
+
 /* Initialize the mouse module. */
 void
 mouse_init(void)
 {
     /* Initialize local data. */
-    mouse_x = mouse_y = mouse_z = 0;
+    mouse_clear_coords();
     mouse_buttons               = 0x00;
 
     mouse_type     = MOUSE_TYPE_NONE;
@@ -159,6 +174,132 @@ mouse_close(void)
     timer_stop(&mouse_timer);
 }
 
+static int
+mouse_scale_coord_x(int x, int mul)
+{
+    double temp_x = (double) x;
+    double ratio = (double) monitors[0].mon_unscaled_size_x / (double) monitors[0].mon_res_x;
+
+    if (mul)
+        temp_x *= ratio;
+    else
+        temp_x /= ratio;
+
+    return (int) temp_x;
+}
+
+static int
+mouse_scale_coord_y(int y, int mul)
+{
+    double temp_y = (double) y;
+    double ratio = (double) monitors[0].mon_efscrnsz_y / (double) monitors[0].mon_res_y;
+
+    if (mul)
+        temp_y *= ratio;
+    else
+        temp_y /= ratio;
+
+    return (int) temp_y;
+}
+
+/* It appears all host platforms give us y in the Microsoft format
+   (positive to the south), so for all non-Microsoft report formsts,
+   we have to invenrt that. */
+void
+mouse_subtract_coords(int *delta_x, int *delta_y, int *o_x, int *o_y,
+                      int min, int max, int invert, int abs)
+{
+    int real_x = mouse_x;
+    int real_y = mouse_y;
+    int smax_x;
+    int smax_y;
+    int rsmin_x;
+    int rsmin_y;
+    int smin_x;
+    int smin_y;
+
+    if (invert)
+        real_y = -real_y;
+
+    rsmin_x = mouse_scale_coord_x(min, 0);
+    rsmin_y = mouse_scale_coord_y(min, 0);
+    if (abs) {
+        smax_x = mouse_scale_coord_x(max, 0) + ABS(rsmin_x);
+        smax_y = mouse_scale_coord_y(max, 0) + ABS(rsmin_y);
+        max += ABS(min);
+        real_x += rsmin_x;
+        real_y += rsmin_y;
+        smin_x = 0;
+        smin_y = 0;
+    } else {
+        smax_x = mouse_scale_coord_x(max, 0);
+        smax_y = mouse_scale_coord_y(max, 0);
+        smin_x = rsmin_x;
+        smin_y = rsmin_y;
+    }
+
+    /* Default the X and Y overflows to 1. */
+    if (o_x != NULL)
+        *o_x = 1;
+    if (o_y != NULL)
+        *o_y = 1;
+
+    if (real_x > smax_x) {
+        if (abs)
+            *delta_x = mouse_scale_coord_x(real_x, 1);
+        else
+            *delta_x = max;
+        real_x -= smax_x;
+    } else if (real_x < smin_x) {
+        if (abs)
+            *delta_x = mouse_scale_coord_x(real_x, 1);
+         else
+            *delta_x = min;
+        real_x += ABS(smin_x);
+    } else {
+        if (abs)
+            *delta_x = mouse_scale_coord_x(real_x, 1);
+        else
+            *delta_x = mouse_scale_coord_x(real_x, 1);
+        real_x = 0;
+        if (o_x != NULL)
+            *o_x = 0;
+    }
+
+    if (real_y > smax_y) {
+        if (abs)
+            *delta_y = mouse_scale_coord_y(real_y, 1);
+        else
+            *delta_y = max;
+        real_y -= smax_y;
+    } else if (real_y < smin_y) {
+        if (abs)
+            *delta_y = mouse_scale_coord_y(real_y, 1);
+         else
+            *delta_y = min;
+        real_y += ABS(smin_y);
+    } else {
+        if (abs)
+            *delta_y = mouse_scale_coord_y(real_y, 1);
+        else
+            *delta_y = mouse_scale_coord_y(real_y, 1);
+        real_y = 0;
+        if (o_y != NULL)
+            *o_y = 0;
+    }
+
+    if (abs) {
+        real_x -= rsmin_x;
+        real_y -= rsmin_y;
+    }
+
+    if (invert)
+        real_y = -real_y;
+
+    mouse_x = real_x;
+    mouse_y = real_y;
+}
+
 static void
 mouse_timer_poll(UNUSED(void *priv))
 {
@@ -178,8 +319,11 @@ mouse_timer_poll(UNUSED(void *priv))
 void
 mouse_scale(int x, int y)
 {
-    double scaled_x = (((double) x) * mouse_sensitivity) + mouse_x_error;
-    double scaled_y = (((double) y) * mouse_sensitivity) + mouse_y_error;
+    double scaled_x = (((double) x) * mouse_sensitivity);
+    double scaled_y = (((double) y) * mouse_sensitivity);
+
+    scaled_x += mouse_x_error;
+    scaled_y += mouse_y_error;
 
     mouse_x += (int) scaled_x;
     mouse_y += (int) scaled_y;
@@ -191,21 +335,25 @@ mouse_scale(int x, int y)
 void
 mouse_scale_x(int x)
 {
-    double scaled_x = ((double) x) * mouse_sensitivity + mouse_x_error;
+    double scaled_x = (((double) x) * mouse_sensitivity);
+
+    scaled_x += mouse_x_error;
 
     mouse_x += (int) scaled_x;
 
-    mouse_x_error = scaled_x - ((double) mouse_x);
+    mouse_x_error = scaled_x - floor(scaled_x);
 }
 
 void
 mouse_scale_y(int y)
 {
-    double scaled_y = ((double) y) * mouse_sensitivity + mouse_y_error;
+    double scaled_y = (((double) y) * mouse_sensitivity);
+
+    scaled_y += mouse_y_error;
 
     mouse_y += (int) scaled_y;
 
-    mouse_y_error = scaled_y - ((double) mouse_y);
+    mouse_y_error = scaled_y - floor(scaled_y);
 }
 
 void
@@ -248,7 +396,7 @@ mouse_reset(void)
               mouse_type, mouse_devices[mouse_type].device->name);
 
     /* Clear local data. */
-    mouse_x = mouse_y = mouse_z = 0;
+    mouse_clear_coords();
     mouse_buttons               = 0x00;
     mouse_mode                  = 0;
     mouse_timed                 = 1;
@@ -292,8 +440,7 @@ mouse_process(void)
 
     if ((mouse_mode >= 1) && mouse_poll_ex)
         mouse_poll_ex();
-
-    if ((mouse_dev_poll != NULL) || (mouse_curr->poll != NULL)) {
+    else if ((mouse_mode == 0) && ((mouse_dev_poll != NULL) || (mouse_curr->poll != NULL))) {
         if (mouse_curr->poll != NULL)
             mouse_curr->poll(mouse_x, mouse_y, mouse_z, mouse_buttons, mouse_x_abs, mouse_y_abs, mouse_priv);
         else
diff --git a/src/device/mouse_bus.c b/src/device/mouse_bus.c
index 33ac2ded3..e6229caef 100644
--- a/src/device/mouse_bus.c
+++ b/src/device/mouse_bus.c
@@ -478,7 +478,9 @@ static int
 bm_poll(int x, int y, UNUSED(int z), int b, UNUSED(double abs_x), UNUSED(double abs_y), void *priv)
 {
     mouse_t *dev = (mouse_t *) priv;
-    int xor ;
+    int delta_x;
+    int delta_y;
+    int xor;
 
     if (!mouse_capture && !video_fullscreen)
         return 1;
@@ -514,27 +516,10 @@ bm_poll(int x, int y, UNUSED(int z), int b, UNUSED(double abs_x), UNUSED(double
     if (!dev->timer_enabled) {
         /* If the counters are not frozen, update them. */
         if (!(dev->flags & FLAG_HOLD)) {
-            if (mouse_x > 127) {
-                dev->current_x = 127;
-                mouse_x -= 127;
-            } else if (mouse_x < 1-128) {
-                dev->current_x = -128;
-                mouse_x += 128;
-            } else {
-                dev->current_x = mouse_x;
-                mouse_x = 0;
-            }
+            mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 0, 0);
 
-            if (mouse_y > 127) {
-                dev->current_y = 127;
-                mouse_y -= 127;
-            } else if (mouse_y < 1-128) {
-                dev->current_y = -128;
-                mouse_y += 128;
-            } else {
-                dev->current_y = mouse_y;
-                mouse_y = 0;
-            }
+            dev->current_x = (int8_t) delta_x;
+            dev->current_y = (int8_t) delta_y;
 
             dev->current_b = dev->mouse_buttons;
         }
@@ -561,27 +546,7 @@ bm_update_data(mouse_t *dev)
     /* If the counters are not frozen, update them. */
     if ((mouse_capture || video_fullscreen) && !(dev->flags & FLAG_HOLD)) {
         /* Update the deltas and the delays. */
-        if (mouse_x > 127) {
-            delta_x = 127;
-            mouse_x -= 127;
-        } else if (mouse_x < -128) {
-            delta_x = -128;
-            mouse_x += 128;
-        } else {
-            delta_x = mouse_x;
-            mouse_x = 0;
-        }
-
-        if (mouse_y > 127) {
-            delta_y = 127;
-            mouse_y -= 127;
-        } else if (mouse_y < -128) {
-            delta_y = -128;
-            mouse_y += 128;
-        } else {
-            delta_y = mouse_y;
-            mouse_y = 0;
-        }
+        mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 0, 0);
 
         dev->current_x = (int8_t) delta_x;
         dev->current_y = (int8_t) delta_y;
diff --git a/src/device/mouse_ps2.c b/src/device/mouse_ps2.c
index f78fc55c4..048092f4c 100644
--- a/src/device/mouse_ps2.c
+++ b/src/device/mouse_ps2.c
@@ -75,35 +75,19 @@ static void
 ps2_report_coordinates(atkbc_dev_t *dev, int main)
 {
     uint8_t buff[3] = { 0x08, 0x00, 0x00 };
+    int delta_x;
+    int delta_y;
+    int overflow_x;
+    int overflow_y;
     int temp_z;
 
-    if (mouse_x > 255) {
-        buff[0] |= 0x40;
-        buff[1] = 255;
-        mouse_x -= 255;
-    } else if (mouse_x < -256) {
-        buff[0] |= (0x40 | 0x10);
-        mouse_x += 256;
-    } else {
-        if (mouse_x < 0)
-            buff[0] |= 0x10;
-        buff[1] = mouse_x;
-        mouse_x = 0;
-    }
-
-    if (mouse_y < -255) {
-        buff[0] |= 0x80;
-        buff[2] = 255;
-        mouse_y += 255;
-    } else if (mouse_y > 256) {
-        buff[0] |= (0x80 | 0x20);
-        mouse_y -= 256;
-    } else {
-        if (mouse_y > 0)
-            buff[0] |= 0x20;
-        buff[2] = -mouse_y;
-        mouse_y = 0;
-    }
+    mouse_subtract_coords(&delta_x, &delta_y, &overflow_x, &overflow_y,
+                          -256, 255, 1, 0);
+    buff[0] = (overflow_y << 7) | (overflow_x << 6) |
+              ((delta_y & 0x0100) >> 3) | ((delta_x & 0x0100) >> 4) |
+              (mouse_buttons & ((dev->flags & FLAG_INTELLI) ? 0x07 : 0x03));
+    buff[1] = (delta_x & 0x00ff);
+    buff[2] = (delta_y & 0x00ff);
 
     if (dev->z < -7) {
         temp_z = 7;
@@ -116,8 +100,6 @@ ps2_report_coordinates(atkbc_dev_t *dev, int main)
         mouse_z = 0;
     }
 
-    buff[0] |= (mouse_buttons & ((dev->flags & FLAG_INTELLI) ? 0x07 : 0x03));
-
     kbc_at_dev_queue_add(dev, buff[0], main);
     kbc_at_dev_queue_add(dev, buff[1], main);
     kbc_at_dev_queue_add(dev, buff[2], main);
diff --git a/src/device/mouse_serial.c b/src/device/mouse_serial.c
index 09df1e409..986d18b74 100644
--- a/src/device/mouse_serial.c
+++ b/src/device/mouse_serial.c
@@ -82,8 +82,6 @@ typedef struct mouse_t {
     int8_t      type;  /* type of this device */
     int8_t      port;
 
-    int         abs_x;
-    int         abs_y;
     int         old_buttons;
     int         state;
     int         bps;
@@ -177,89 +175,13 @@ sermouse_transmit(mouse_t *dev, int len, int from_report, int to_report)
         sermouse_set_period(dev, dev->transmit_period);
 }
 
-/* It appears all host platforms give us y in the Microsoft format
-   (positive to the south), so for all non-Microsoft report formsts,
-   we have to invenrt that. */
-static void
-sermouse_subtract_coords(mouse_t *dev, int *delta_x, int *delta_y, int min, int max, int invert, int abs)
-{
-    int real_y = mouse_y;
-    int abs_max = max + ABS(min);
-
-    if (invert)
-        real_y = -real_y;
-
-    if (mouse_x > max) {
-        if (abs) {
-            dev->abs_x += max;
-            *delta_x = dev->abs_x;
-        } else
-            *delta_x = max;
-        mouse_x -= max;
-    } else if (mouse_x < min) {
-        if (abs) {
-            dev->abs_x += min;
-            *delta_x = dev->abs_x;
-        } else
-            *delta_x = min;
-        mouse_x += ABS(min);
-    } else {
-        if (abs) {
-            dev->abs_x += mouse_x;
-            *delta_x = dev->abs_x;
-        } else
-            *delta_x = mouse_x;
-        mouse_x = 0;
-    }
-
-    if (real_y > max) {
-        if (abs) {
-            dev->abs_y += max;
-            *delta_y = dev->abs_y;
-        } else
-            *delta_y = max;
-        real_y -= max;
-    } else if (real_y < min) {
-        if (abs) {
-            dev->abs_y += min;
-            *delta_y = dev->abs_y;
-        } else
-            *delta_y = min;
-        real_y += ABS(min);
-    } else {
-        if (abs) {
-            dev->abs_y += real_y;
-            *delta_y = dev->abs_y;
-        } else
-            *delta_y = real_y;
-        real_y = 0;
-    }
-
-    if (abs) {
-        if (dev->abs_x < 0)
-            *delta_x = 0;
-        else if (dev->abs_x > abs_max)
-            *delta_x = abs_max;
-
-        if (dev->abs_y < 0)
-            *delta_y = 0;
-        else if (dev->abs_y > abs_max)
-            *delta_y = abs_max;
-    }
-
-    if (invert)
-        real_y = -real_y;
-
-    mouse_y = real_y;
-}
-
 static uint8_t
 sermouse_report_msystems(mouse_t *dev)
 {
     int delta_x = 0;
     int delta_y = 0;
 
-    sermouse_subtract_coords(dev, &delta_x, &delta_y, -128, 127, 1, 0);
+    mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 1, 0);
 
     dev->buf[0] = 0x80;
     dev->buf[0] |= (mouse_buttons & 0x01) ? 0x00 : 0x04; /* left button */
@@ -282,7 +204,7 @@ sermouse_report_3bp(mouse_t *dev)
     int delta_x = 0;
     int delta_y = 0;
 
-    sermouse_subtract_coords(dev, &delta_x, &delta_y, -128, 127, 1, 0);
+    mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 1, 0);
 
     dev->buf[0] = 0x80;
     dev->buf[0] |= (mouse_buttons & 0x01) ? 0x04 : 0x00; /* left button */
@@ -303,7 +225,7 @@ sermouse_report_mmseries(mouse_t *dev)
     int delta_x = 0;
     int delta_y = 0;
 
-    sermouse_subtract_coords(dev, &delta_x, &delta_y, -127, 127, 1, 0);
+    mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -127, 127, 1, 0);
 
     dev->buf[0] = 0x80;
     if (delta_x >= 0)
@@ -328,7 +250,7 @@ sermouse_report_bp1(mouse_t *dev, int abs)
     int delta_x = 0;
     int delta_y = 0;
 
-    sermouse_subtract_coords(dev, &delta_x, &delta_y, -2048, 2047, 1, abs);
+    mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -2048, 2047, 1, abs);
 
     dev->buf[0] = 0x80;
     dev->buf[0] |= (mouse_buttons & 0x01) ? 0x10 : 0x00; /* left button */
@@ -351,7 +273,7 @@ sermouse_report_ms(mouse_t *dev)
     int delta_y = 0;
     int delta_z = 0;
 
-    sermouse_subtract_coords(dev, &delta_x, &delta_y, -128, 127, 0, 0);
+    mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 0, 0);
 
     dev->buf[0] = 0x40;
     dev->buf[0] |= (((delta_y >> 6) & 0x03) << 2);
@@ -409,7 +331,7 @@ sermouse_report_hex(mouse_t *dev)
     int delta_x = 0;
     int delta_y = 0;
 
-    sermouse_subtract_coords(dev, &delta_x, &delta_y, -128, 127, 1, 0);
+    mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 1, 0);
 
     but |= (mouse_buttons & 0x01) ? 0x04 : 0x00; /* left button */
     if (dev->but >= 3)
@@ -669,7 +591,7 @@ ltsermouse_process_command(mouse_t *dev)
 
         case 0x41:
             /* Absolute Bit Pad One Packed Binary Format */
-            dev->abs_x = dev->abs_y = 0;
+            mouse_clear_coords();
             fallthrough;
         case 0x42:    /* Relative Bit Pad One Packed Binary Format */
         case 0x53:    /* MM Series Data Format */
diff --git a/src/include/86box/86box.h b/src/include/86box/86box.h
index 2f16c92d7..f65f58f63 100644
--- a/src/include/86box/86box.h
+++ b/src/include/86box/86box.h
@@ -143,8 +143,10 @@ extern int is_pentium; /* TODO: Move back to cpu/cpu.h when it's figured out,
 extern int    fixed_size_x;
 extern int    fixed_size_y;
 extern double mouse_sensitivity;            /* (C) Mouse sensitivity scale */
-extern double mouse_x_error;     /* Mouse error accumulator - Y */
-extern double mouse_y_error;     /* Mouse error accumulator - Y */
+#ifdef _Atomic
+extern _Atomic double mouse_x_error;     /* Mouse error accumulator - Y */
+extern _Atomic double mouse_y_error;     /* Mouse error accumulator - Y */
+#endif
 extern int    pit_mode;                     /* (C) force setting PIT mode */
 extern int    fm_driver;                    /* (C) select FM sound driver */
 
diff --git a/src/include/86box/mouse.h b/src/include/86box/mouse.h
index d8d609fbb..6bc125623 100644
--- a/src/include/86box/mouse.h
+++ b/src/include/86box/mouse.h
@@ -26,7 +26,7 @@
 #endif
 
 #define MOUSE_TYPE_NONE     0 /* no mouse configured */
-#define MOUSE_TYPE_INTERNAL 1 /* machine has internal mouse */
+#define MOUSE_TYPE_INTERNAL 1 /* achine has internal mouse */
 #define MOUSE_TYPE_LOGIBUS  2 /* Logitech/ATI Bus Mouse */
 #define MOUSE_TYPE_INPORT   3 /* Microsoft InPort Mouse */
 #if 0
@@ -62,8 +62,10 @@ extern double mouse_x_abs;
 extern double mouse_y_abs;
 extern int    tablet_tool_type;
 extern double mouse_sensitivity;
-extern double mouse_x_error;
-extern double mouse_y_error;
+#ifdef _Atomic
+extern _Atomic double mouse_x_error;
+extern _Atomic double mouse_y_error;
+#endif
 
 #ifdef EMU_DEVICE_H
 extern const device_t *mouse_get_device(int mouse);
@@ -83,8 +85,11 @@ extern const device_t mouse_wacom_device;
 extern const device_t mouse_wacom_artpad_device;
 #endif
 
+extern void mouse_clear_coords(void);
 extern void mouse_init(void);
 extern void mouse_close(void);
+extern void mouse_subtract_coords(int *delta_x, int *delta_y, int *o_x, int *o_y,
+                                  int min, int max, int invert, int abs);
 extern void mouse_reset(void);
 extern void mouse_set_buttons(int buttons);
 extern void mouse_set_poll_ex(void (*poll_ex)(void));
diff --git a/src/include/86box/plat.h b/src/include/86box/plat.h
index 03f5584c1..44b0c691f 100644
--- a/src/include/86box/plat.h
+++ b/src/include/86box/plat.h
@@ -143,6 +143,7 @@ extern void     plat_vid_reload_options(void);
 extern uint32_t plat_language_code(char *langcode);
 extern void     plat_language_code_r(uint32_t lcid, char *outbuf, int len);
 extern void     plat_get_cpu_string(char *outbuf, uint8_t len);
+extern double   plat_get_dpi(void);
 
 /* Resource management. */
 extern void     set_language(uint32_t id);
diff --git a/src/pic.c b/src/pic.c
index fdfed7d26..6999aa6d8 100644
--- a/src/pic.c
+++ b/src/pic.c
@@ -236,7 +236,12 @@ pic_update_pending_at(void)
     if (!(pic2.flags & PIC_FREEZE)) {
         pic2.int_pending = (find_best_interrupt(&pic2) != -1);
 
-        pic_cascade(pic2.int_pending);
+        // pic_cascade(pic2.int_pending);
+
+        if (pic2.int_pending)
+            pic.irr |= (1 << pic2.icw3);
+        else
+            pic.irr &= ~(1 << pic2.icw3);
     }
 
     if (!(pic.flags & PIC_FREEZE))
@@ -375,6 +380,7 @@ pic_action(pic_t *dev, uint8_t irq, uint8_t eoi, uint8_t rotate)
         if (rotate)
             dev->priority = (irq + 1) & 7;
 
+        pic_update_request(dev, irq);
         update_pending();
     }
 }
@@ -414,13 +420,10 @@ pic_latch_read(UNUSED(uint16_t addr), UNUSED(void *priv))
 {
     uint8_t ret = 0xff;
 
-    pic_log("pic_latch_read(%04X): %02X%02X\n", enabled_latches, latched_irqs & 0x10, latched_irqs & 0x02);
+    pic_log("pic_latch_read(%04X): %04X\n", enabled_latches, latched_irqs & 0x1002);
 
-    if ((latched_irqs & enabled_latches) & 0x0002)
-        picintc(0x0002);
-
-    if ((latched_irqs & enabled_latches) & 0x1000)
-        picintc(0x1000);
+    if (latched_irqs & 0x1002)
+        picintc(latched_irqs & 0x1002);
 
     /* Return FF - we just lower IRQ 1 and IRQ 12. */
     return ret;
diff --git a/src/qt/qt_platform.cpp b/src/qt/qt_platform.cpp
index bddcd295c..7a028bfac 100644
--- a/src/qt/qt_platform.cpp
+++ b/src/qt/qt_platform.cpp
@@ -42,9 +42,12 @@
 #include <QLibrary>
 #include <QElapsedTimer>
 
+#include <QScreen>
+
 #include "qt_rendererstack.hpp"
 #include "qt_mainwindow.hpp"
 #include "qt_progsettings.hpp"
+#include "qt_util.hpp"
 
 #ifdef Q_OS_UNIX
 #    include <sys/mman.h>
@@ -641,7 +644,7 @@ plat_get_global_config_dir(char* strptr)
 }
 
 void
-plat_init_rom_paths()
+plat_init_rom_paths(void)
 {
     auto paths = QStandardPaths::standardLocations(QStandardPaths::GenericDataLocation);
 
@@ -727,4 +730,10 @@ plat_get_cpu_string(char *outbuf, uint8_t len) {
 
     qstrncpy(outbuf, cpu_string.toUtf8().constData(), len);
 
-}
\ No newline at end of file
+}
+
+double
+plat_get_dpi(void)
+{
+    return util::screenOfWidget(main_window)->devicePixelRatio();
+}
diff --git a/src/qt/qt_renderercommon.cpp b/src/qt/qt_renderercommon.cpp
index c2b38cd52..0f16257d7 100644
--- a/src/qt/qt_renderercommon.cpp
+++ b/src/qt/qt_renderercommon.cpp
@@ -27,6 +27,7 @@
 
 extern "C" {
 #include <86box/86box.h>
+#include <86box/plat.h>
 #include <86box/video.h>
 }
 
@@ -51,62 +52,71 @@ integer_scale(double *d, double *g)
 void
 RendererCommon::onResize(int width, int height)
 {
-    if ((video_fullscreen == 0) && (video_fullscreen_scale_maximized ? ((parentWidget->isMaximized() == false) && (main_window->isAncestorOf(parentWidget) && main_window->isMaximized() == false)) : 1)) {
+    /* This is needed so that the if below does not take like, 5 lines. */
+    bool is_fs = (video_fullscreen == 0);
+    bool parent_max = (parentWidget->isMaximized() == false);
+    bool main_is_ancestor = main_window->isAncestorOf(parentWidget);
+    bool main_max = main_window->isMaximized();
+    bool main_is_max = (main_is_ancestor && main_max == false);
+
+    if (is_fs && (video_fullscreen_scale_maximized ? (parent_max && main_is_max) : 1))
         destination.setRect(0, 0, width, height);
-        return;
-    }
-    double dx;
-    double dy;
-    double dw;
-    double dh;
-    double gsr;
+    else {
+        double dx;
+        double dy;
+        double dw;
+        double dh;
+        double gsr;
 
-    double hw  = width;
-    double hh  = height;
-    double gw  = source.width();
-    double gh  = source.height();
-    double hsr = hw / hh;
+        double hw  = width;
+        double hh  = height;
+        double gw  = source.width();
+        double gh  = source.height();
+        double hsr = hw / hh;
 
-    switch (video_fullscreen_scale) {
-        case FULLSCR_SCALE_INT:
-            gsr = gw / gh;
-            if (gsr <= hsr) {
-                dw = hh * gsr;
-                dh = hh;
-            } else {
-                dw = hw;
-                dh = hw / gsr;
-            }
-            integer_scale(&dw, &gw);
-            integer_scale(&dh, &gh);
-            dx = (hw - dw) / 2.0;
-            dy = (hh - dh) / 2.0;
-            destination.setRect(dx, dy, dw, dh);
-            break;
-        case FULLSCR_SCALE_43:
-        case FULLSCR_SCALE_KEEPRATIO:
-            if (video_fullscreen_scale == FULLSCR_SCALE_43) {
-                gsr = 4.0 / 3.0;
-            } else {
+        switch (video_fullscreen_scale) {
+            case FULLSCR_SCALE_INT:
                 gsr = gw / gh;
-            }
+                if (gsr <= hsr) {
+                    dw = hh * gsr;
+                    dh = hh;
+                } else {
+                    dw = hw;
+                    dh = hw / gsr;
+                }
+                integer_scale(&dw, &gw);
+                integer_scale(&dh, &gh);
+                dx = (hw - dw) / 2.0;
+                dy = (hh - dh) / 2.0;
+                destination.setRect((int) dx, (int) dy, (int) dw, (int) dh);
+                break;
+            case FULLSCR_SCALE_43:
+            case FULLSCR_SCALE_KEEPRATIO:
+                if (video_fullscreen_scale == FULLSCR_SCALE_43)
+                    gsr = 4.0 / 3.0;
+                else
+                    gsr = gw / gh;
 
-            if (gsr <= hsr) {
-                dw = hh * gsr;
-                dh = hh;
-            } else {
-                dw = hw;
-                dh = hw / gsr;
-            }
-            dx = (hw - dw) / 2.0;
-            dy = (hh - dh) / 2.0;
-            destination.setRect(dx, dy, dw, dh);
-            break;
-        case FULLSCR_SCALE_FULL:
-        default:
-            destination.setRect(0, 0, hw, hh);
-            break;
+                if (gsr <= hsr) {
+                    dw = hh * gsr;
+                    dh = hh;
+                } else {
+                    dw = hw;
+                    dh = hw / gsr;
+                }
+                dx = (hw - dw) / 2.0;
+                dy = (hh - dh) / 2.0;
+                destination.setRect((int) dx, (int) dy, (int) dw, (int) dh);
+                break;
+            case FULLSCR_SCALE_FULL:
+            default:
+                destination.setRect(0, 0, (int) hw, (int) hh);
+                break;
+        }
     }
+
+    monitors[r_monitor_index].mon_res_x = (int) ((double) destination.width() * plat_get_dpi());
+    monitors[r_monitor_index].mon_res_y = (int) ((double) destination.height() * plat_get_dpi());
 }
 
 bool
diff --git a/src/qt/qt_renderercommon.hpp b/src/qt/qt_renderercommon.hpp
index 34b28fb30..4385a0b73 100644
--- a/src/qt/qt_renderercommon.hpp
+++ b/src/qt/qt_renderercommon.hpp
@@ -38,8 +38,10 @@ public:
     virtual bool hasBlitFunc() { return false; }
     virtual void blit(int x, int y, int w, int h) { }
 
+    int      r_monitor_index = 0;
+
 protected:
-    bool eventDelegate(QEvent *event, bool &result);
+    bool     eventDelegate(QEvent *event, bool &result);
 
     QRect    source { 0, 0, 0, 0 };
     QRect    destination;
diff --git a/src/qt/qt_rendererstack.cpp b/src/qt/qt_rendererstack.cpp
index 7618327c4..54f81d80c 100644
--- a/src/qt/qt_rendererstack.cpp
+++ b/src/qt/qt_rendererstack.cpp
@@ -552,3 +552,19 @@ RendererStack::event(QEvent* event)
     }
     return QStackedWidget::event(event);
 }
+
+void
+RendererStack::setFocusRenderer()
+{
+    if (current)
+        current->setFocus();
+}
+
+void
+RendererStack::onResize(int width, int height)
+{
+    if (rendererWindow) {
+        rendererWindow->r_monitor_index = m_monitor_index;
+        rendererWindow->onResize(width, height);
+    }
+}
diff --git a/src/qt/qt_rendererstack.hpp b/src/qt/qt_rendererstack.hpp
index 7c0820190..f59849dda 100644
--- a/src/qt/qt_rendererstack.hpp
+++ b/src/qt/qt_rendererstack.hpp
@@ -71,16 +71,8 @@ public:
     /* Returns options dialog for current renderer */
     QDialog *getOptions(QWidget *parent) { return rendererWindow ? rendererWindow->getOptions(parent) : nullptr; }
 
-    void setFocusRenderer()
-    {
-        if (current)
-            current->setFocus();
-    }
-    void onResize(int width, int height)
-    {
-        if (rendererWindow)
-            rendererWindow->onResize(width, height);
-    }
+    void setFocusRenderer();
+    void onResize(int width, int height);
 
     void (*mouse_capture_func)(QWindow *window) = nullptr;
     void (*mouse_uncapture_func)()              = nullptr;