diff --git a/src/device/mouse.c b/src/device/mouse.c
index f7d8c9861..0bf87934d 100644
--- a/src/device/mouse.c
+++ b/src/device/mouse.c
@@ -83,23 +83,24 @@ static const device_t mouse_internal_device = {
 
 static mouse_t mouse_devices[] = {
     // clang-format off
-    { &mouse_none_device         },
-    { &mouse_internal_device     },
-    { &mouse_logibus_device      },
-    { &mouse_msinport_device     },
+    { &mouse_none_device          },
+    { &mouse_internal_device      },
+    { &mouse_logibus_device       },
+    { &mouse_msinport_device      },
 #ifdef USE_GENIBUS
-    { &mouse_genibus_device      },
+    { &mouse_genibus_device       },
 #endif
-    { &mouse_mssystems_device    },
-    { &mouse_msserial_device     },
-    { &mouse_ltserial_device     },
-    { &mouse_ps2_device          },
+    { &mouse_mssystems_device     },
+    { &mouse_mssystems_bus_device },
+    { &mouse_msserial_device      },
+    { &mouse_ltserial_device      },
+    { &mouse_ps2_device           },
 #ifdef USE_WACOM
-    { &mouse_wacom_device        },
-    { &mouse_wacom_artpad_device },
+    { &mouse_wacom_device         },
+    { &mouse_wacom_artpad_device  },
 #endif
-    { &mouse_mtouch_device       },
-    { NULL                       }
+    { &mouse_mtouch_device        },
+    { NULL                        }
     // clang-format on
 };
 
diff --git a/src/device/mouse_serial.c b/src/device/mouse_serial.c
index 8ed4865cd..24d7ae853 100644
--- a/src/device/mouse_serial.c
+++ b/src/device/mouse_serial.c
@@ -833,10 +833,6 @@ sermouse_close(void *priv)
 {
     mouse_t *dev = (mouse_t *) priv;
 
-    /* Detach serial port from the mouse. */
-    if (dev && dev->serial && dev->serial->sd)
-        memset(dev->serial->sd, 0, sizeof(serial_device_t));
-
     free(dev);
 }
 
@@ -849,6 +845,11 @@ sermouse_init(const device_t *info)
     void (*dev_write)(struct serial_s *serial, void *priv, uint8_t data);
     void (*transmit_period_callback)(struct serial_s *serial, void *priv, double transmit_period);
 
+    if (info->local == MOUSE_TYPE_MSYSTEMSB) {
+        uintptr_t irqbase = ((device_get_config_int("irq") << 16) | (device_get_config_hex16("addr") << 20)) | ns16450_device.local;
+        device_add_params(&ns16450_device, (void*)irqbase);
+    }
+
     dev = (mouse_t *) calloc(1, sizeof(mouse_t));
     dev->name = info->name;
     dev->but  = device_get_config_int("buttons");
@@ -862,7 +863,7 @@ sermouse_init(const device_t *info)
     if (dev->but > 2)
         dev->flags |= FLAG_3BTN;
 
-    if (info->local == MOUSE_TYPE_MSYSTEMS) {
+    if (info->local == MOUSE_TYPE_MSYSTEMS || info->local == MOUSE_TYPE_MSYSTEMSB) {
         dev->format    = 0;
         dev->type      = info->local;
         dev->id_len    = 1;
@@ -893,7 +894,7 @@ sermouse_init(const device_t *info)
         }
     }
 
-    dev->port = device_get_config_int("port");
+    dev->port = (info->local == MOUSE_TYPE_MSYSTEMSB) ? SERIAL_MAX : device_get_config_int("port");
 
     /* Attach a serial port to the mouse. */
     rcr_callback = dev->rts_toggle ? sermouse_callback : NULL;
@@ -968,6 +969,76 @@ static const device_config_t msssermouse_config[] = {
   // clang-format on
 };
 
+static const device_config_t mssbusmouse_config[] = {
+    // clang-format off
+    {
+        .name           = "addr",
+        .description    = "Address",
+        .type           = CONFIG_HEX16,
+        .default_string = NULL,
+        .default_int    = 0x238,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = {
+            { .description = "0x338", .value = 0x338 },
+            { .description = "0x238", .value = 0x238 },
+            { .description = ""                      }
+        },
+        .bios           = { { 0 } }
+    },
+
+    {
+        .name           = "irq",
+        .description    = "IRQ",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 5,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = {
+            { .description = "IRQ 2",   .value =  2 },
+            { .description = "IRQ 3",   .value =  3 },
+            { .description = "IRQ 4",   .value =  4 },
+            { .description = "IRQ 5",   .value =  5 },
+            { .description = "IRQ 7",   .value =  7 },
+            { .description = "IRQ 10",  .value = 10 },
+            { .description = "IRQ 11",  .value = 11 },
+            { .description = "IRQ 12",  .value = 12 },
+            { .description = "IRQ 15",  .value = 15 },
+            { .description = ""                     }
+        },
+        .bios           = { { 0 } }
+    },
+    {
+        .name           = "buttons",
+        .description    = "Buttons",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 2,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = {
+            { .description = "Two",   .value = 2 },
+            { .description = "Three", .value = 3 },
+            { .description = ""                  }
+        },
+        .bios           = { { 0 } }
+    },
+    {
+        .name           = "rts_toggle",
+        .description    = "RTS toggle",
+        .type           = CONFIG_BINARY,
+        .default_string = NULL,
+        .default_int    = 0,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = { { 0 } },
+        .bios           = { { 0 } }
+    },
+    { .name = "", .description = "", .type = CONFIG_END }
+    // clang-format on
+  };
+
 static const device_config_t mssermouse_config[] = {
   // clang-format off
     {
@@ -1087,6 +1158,20 @@ const device_t mouse_mssystems_device = {
     .config        = msssermouse_config
 };
 
+const device_t mouse_mssystems_bus_device = {
+    .name          = "Mouse Systems Bus Mouse",
+    .internal_name = "mssystems_bus",
+    .flags         = DEVICE_ISA,
+    .local         = MOUSE_TYPE_MSYSTEMSB,
+    .init          = sermouse_init,
+    .close         = sermouse_close,
+    .reset         = NULL,
+    .available     = NULL,
+    .speed_changed = sermouse_speed_changed,
+    .force_redraw  = NULL,
+    .config        = mssbusmouse_config
+};
+
 const device_t mouse_msserial_device = {
     .name          = "Microsoft Serial Mouse",
     .internal_name = "msserial",
diff --git a/src/device/serial.c b/src/device/serial.c
index deb97225a..c00cfad10 100644
--- a/src/device/serial.c
+++ b/src/device/serial.c
@@ -38,7 +38,7 @@
 #include <86box/serial.h>
 #include <86box/mouse.h>
 
-serial_port_t com_ports[SERIAL_MAX];
+serial_port_t com_ports[SERIAL_MAX + 1];
 
 enum {
     SERIAL_INT_LSR       = 1,
@@ -53,7 +53,7 @@ enum {
 void    serial_update_ints(serial_t *dev);
 
 static int             next_inst = 0;
-static serial_device_t serial_devices[SERIAL_MAX];
+static serial_device_t serial_devices[SERIAL_MAX + 1];
 
 static void            serial_xmit_d_empty_evt(void *priv);
 
@@ -884,10 +884,10 @@ serial_close(void *priv)
 {
     serial_t *dev = (serial_t *) priv;
 
-    next_inst--;
-
-    if (com_ports[dev->inst].enabled)
+    if (dev->sd) {
+        memset(dev->sd, 0, sizeof(serial_device_t));
         fifo_close(dev->rcvr_fifo);
+    }
 
     free(dev);
 }
@@ -897,7 +897,7 @@ serial_reset(void *priv)
 {
     serial_t *dev = (serial_t *) priv;
 
-    if (com_ports[dev->inst].enabled) {
+    if (dev->sd) {
         timer_disable(&dev->transmit_timer);
         timer_disable(&dev->timeout_timer);
         timer_disable(&dev->receive_timer);
@@ -930,16 +930,28 @@ static void *
 serial_init(const device_t *info)
 {
     serial_t *dev = (serial_t *) calloc(1, sizeof(serial_t));
+    int orig_inst = next_inst;
+
+    if (info->local & 0xFFF00000) {
+        next_inst = SERIAL_MAX;
+    }
 
     dev->inst = next_inst;
 
-    if (com_ports[next_inst].enabled) {
+    if (com_ports[next_inst].enabled || (info->local & 0xFFF00000)) {
         serial_log("Adding serial port %i...\n", next_inst);
         dev->type = info->local;
         memset(&(serial_devices[next_inst]), 0, sizeof(serial_device_t));
         dev->sd         = &(serial_devices[next_inst]);
         dev->sd->serial = dev;
-        if (next_inst == 6)
+
+        if (info->local & 0xFFF00000) {
+            dev->base_address = info->local >> 20;
+            dev->irq          = (info->local >> 16) & 0xF;
+            io_sethandler(dev->base_address, 0x0008, serial_read, NULL, NULL, serial_write, NULL, NULL, dev);
+            next_inst = orig_inst;
+        }
+        else if (next_inst == 6)
             serial_setup(dev, COM7_ADDR, COM7_IRQ);
         else if (next_inst == 5)
             serial_setup(dev, COM6_ADDR, COM6_IRQ);
@@ -984,7 +996,8 @@ serial_init(const device_t *info)
         serial_reset_port(dev);
     }
 
-    next_inst++;
+    if (!(info->local & 0xFFF00000))
+        next_inst++;
 
     return dev;
 }
diff --git a/src/include/86box/mouse.h b/src/include/86box/mouse.h
index 333849846..8dd3bad2d 100644
--- a/src/include/86box/mouse.h
+++ b/src/include/86box/mouse.h
@@ -41,6 +41,7 @@
 #define MOUSE_TYPE_PS2       11 /* PS/2 series Bus Mouse */
 #define MOUSE_TYPE_WACOM     12 /* WACOM tablet */
 #define MOUSE_TYPE_WACOMARTP 13 /* WACOM tablet (ArtPad) */
+#define MOUSE_TYPE_MSYSTEMSB 14 /* Mouse Systems bus mouse */
 
 #define MOUSE_TYPE_ONBOARD   0x80 /* Mouse is an on-board version of one of the above. */
 
@@ -68,6 +69,7 @@ extern const device_t mouse_msinport_device;
 extern const device_t mouse_genibus_device;
 #    endif
 extern const device_t mouse_mssystems_device;
+extern const device_t mouse_mssystems_bus_device;
 extern const device_t mouse_msserial_device;
 extern const device_t mouse_ltserial_device;
 extern const device_t mouse_ps2_device;
diff --git a/src/include/86box/serial.h b/src/include/86box/serial.h
index 31c77ce5a..c6259d7bc 100644
--- a/src/include/86box/serial.h
+++ b/src/include/86box/serial.h
@@ -116,7 +116,7 @@ typedef struct serial_port_s {
     uint8_t enabled;
 } serial_port_t;
 
-extern serial_port_t com_ports[SERIAL_MAX];
+extern serial_port_t com_ports[SERIAL_MAX + 1];
 
 extern serial_t *serial_attach_ex(int port,
                                   void (*rcr_callback)(struct serial_s *serial, void *priv),