diff --git a/src/cpu/x86.c b/src/cpu/x86.c
index 1b0de661b..1090f22a1 100644
--- a/src/cpu/x86.c
+++ b/src/cpu/x86.c
@@ -283,7 +283,7 @@ reset_common(int hard)
         cr0 = 1 << 30;
     else
         cr0 = 0;
-    if (is386 && !is486 && (fpu_type == FPU_387))
+    if (is386 && !is486 && ((fpu_type == FPU_387) || (fpu_type == FPU_NONE)))
         cr0 |= 0x10;
     cpu_cache_int_enabled = 0;  
     cpu_update_waitstates();
diff --git a/src/include/86box/chipset.h b/src/include/86box/chipset.h
index 10d1fa471..31bfc09d6 100644
--- a/src/include/86box/chipset.h
+++ b/src/include/86box/chipset.h
@@ -135,6 +135,7 @@ extern const device_t opti481_device;
 extern const device_t opti493_device;
 extern const device_t opti495slc_device;
 extern const device_t opti495sx_device;
+extern const device_t opti496_device;
 extern const device_t opti498_device;
 extern const device_t opti499_device;
 extern const device_t opti601_device;
diff --git a/src/include/86box/machine.h b/src/include/86box/machine.h
index 0afa881e2..06fdd00b8 100644
--- a/src/include/86box/machine.h
+++ b/src/include/86box/machine.h
@@ -263,6 +263,7 @@ enum {
     MACHINE_CHIPSET_OPTI_493,
     MACHINE_CHIPSET_OPTI_495SLC,
     MACHINE_CHIPSET_OPTI_495SX,
+    MACHINE_CHIPSET_OPTI_496,
     MACHINE_CHIPSET_OPTI_498,
     MACHINE_CHIPSET_OPTI_499,
     MACHINE_CHIPSET_OPTI_895_802G,
@@ -566,6 +567,9 @@ extern int             machine_at_neat_init(const machine_t *);
 /* NEATsx */
 extern int             machine_at_if386sx_init(const machine_t *);
 
+/* OPTi 283 */
+extern int             machine_at_svc386sxp1_init(const machine_t *);
+
 /* OPTi 291 */
 extern int             machine_at_awardsx_init(const machine_t *);
 
@@ -648,6 +652,9 @@ extern int             machine_at_cs4031_init(const machine_t *);
 /* OPTi 381 */
 extern int             machine_at_ga486l_init(const machine_t *);
 
+/* OPTi 493 */
+extern int             machine_at_svc486wb_init(const machine_t *);
+
 /* OPTi 498 */
 extern int             machine_at_mvi486_init(const machine_t *);
 
diff --git a/src/machine/m_at_386sx.c b/src/machine/m_at_386sx.c
index d52cd6611..82ae3b79d 100644
--- a/src/machine/m_at_386sx.c
+++ b/src/machine/m_at_386sx.c
@@ -447,6 +447,29 @@ machine_at_if386sx_init(const machine_t *model)
     return ret;
 }
 
+/* OPTi 283 */
+int
+machine_at_svc386sxp1_init(const machine_t *model)
+{
+    int ret;
+
+    ret = bios_load_linear("roms/machines/svc386sxp1/svc-386sx-am27c512dip28-6468c04f09d89320349795.bin",
+                           0x000f0000, 65536, 0);
+
+    if (bios_only || !ret)
+        return ret;
+
+    machine_at_common_init(model);
+
+    device_add(&opti283_device);
+    device_add(&kbc_at_ami_device);
+
+    if (fdc_current[0] == FDC_INTERNAL)
+        device_add(&fdc_at_device);
+
+    return ret;
+}
+
 /* OPTi 291 */
 int
 machine_at_awardsx_init(const machine_t *model)
diff --git a/src/machine/m_at_socket1.c b/src/machine/m_at_socket1.c
index c854792ad..960bbce07 100644
--- a/src/machine/m_at_socket1.c
+++ b/src/machine/m_at_socket1.c
@@ -92,6 +92,28 @@ machine_at_ga486l_init(const machine_t *model)
     return ret;
 }
 
+/* OPTi 493 */
+int
+machine_at_svc486wb_init(const machine_t *model)
+{
+    int ret;
+
+    ret = bios_load_linear("roms/machines/svc486wb/svc486wb-AM27C512DIP28.BIN",
+                           0x000f0000, 65536, 0);
+
+    if (bios_only || !ret)
+        return ret;
+
+    machine_at_common_init(model);
+
+    device_add(&opti493_device);
+
+    device_add(&kbc_at_ami_device);
+    device_add(&ide_isa_device);
+
+    return ret;
+}
+
 /* OPTi 498 */
 int
 machine_at_mvi486_init(const machine_t *model)
diff --git a/src/machine/machine_table.c b/src/machine/machine_table.c
index 4930910d5..39bced303 100644
--- a/src/machine/machine_table.c
+++ b/src/machine/machine_table.c
@@ -121,6 +121,7 @@ const machine_filter_t machine_chipsets[] = {
     { "OPTi 493",                   MACHINE_CHIPSET_OPTI_493            },
     { "OPTi 495SLC",                MACHINE_CHIPSET_OPTI_495SLC         },
     { "OPTi 495SX",                 MACHINE_CHIPSET_OPTI_495SX          },
+    { "OPTi 496",                   MACHINE_CHIPSET_OPTI_496            },
     { "OPTi 498",                   MACHINE_CHIPSET_OPTI_498            },
     { "OPTi 499",                   MACHINE_CHIPSET_OPTI_499            },
     { "OPTi 895/802G",              MACHINE_CHIPSET_OPTI_895_802G       },
@@ -5312,6 +5313,49 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
+    /* Has AMI KBC firmware of uknown revision, maybe '8'. */
+    {
+        .name = "[OPTi 283] Silicon Valley SVC386SX/P1",
+        .internal_name = "svc386sxp1",
+        .type = MACHINE_TYPE_386SX,
+        .chipset = MACHINE_CHIPSET_OPTI_283,
+        .init = machine_at_svc386sxp1_init,
+        .p1_handler = NULL,
+        .gpio_handler = NULL,
+        .available_flag = MACHINE_AVAILABLE,
+        .gpio_acpi_handler = NULL,
+        .cpu = {
+            .package = CPU_PKG_386SX,
+            .block = CPU_BLOCK_NONE,
+            .min_bus = 0,
+            .max_bus = 0,
+            .min_voltage = 0,
+            .max_voltage = 0,
+            .min_multi = 0,
+            .max_multi = 0
+        },
+        .bus_flags = MACHINE_AT,
+        .flags = MACHINE_APM,
+        .ram = {
+            .min = 1024,
+            .max = 16384,
+            .step = 1024
+        },
+        .nvrmask = 127,
+        .jumpered_ecp_dma = 0,
+        .default_jumpered_ecp_dma = -1,
+        .kbc_device = NULL,
+        .kbc_p1 = 0xff,
+        .gpio = 0xffffffff,
+        .gpio_acpi = 0xffffffff,
+        .device = NULL,
+        .kbd_device = NULL,
+        .fdc_device = NULL,
+        .sio_device = NULL,
+        .vid_device = NULL,
+        .snd_device = NULL,
+        .net_device = NULL
+    },
     /* Has IBM AT KBC firmware. */
     {
         .name = "[OPTi 291] DTK PPM-3333P",
@@ -6923,6 +6967,49 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
+    /* Uses the AMIKey 'F' keyboard controller firmware. */
+    {
+        .name = "[OPTi 493] Silicon Valley Computer 486WB",
+        .internal_name = "svc486wb",
+        .type = MACHINE_TYPE_486,
+        .chipset = MACHINE_CHIPSET_OPTI_493,
+        .init = machine_at_svc486wb_init,
+        .p1_handler = NULL,
+        .gpio_handler = NULL,
+        .available_flag = MACHINE_AVAILABLE,
+        .gpio_acpi_handler = NULL,
+        .cpu = {
+            .package = CPU_PKG_SOCKET1,
+            .block = CPU_BLOCK_NONE,
+            .min_bus = 20000000,
+            .max_bus = 33333333,
+            .min_voltage = 0,
+            .max_voltage = 0,
+            .min_multi = 0,
+            .max_multi = 2.0
+        },
+        .bus_flags = MACHINE_AT,
+        .flags = MACHINE_IDE | MACHINE_APM,
+        .ram = {
+            .min = 1024,
+            .max = 32768,
+            .step = 1024
+        },
+        .nvrmask = 127,
+        .jumpered_ecp_dma = 0,
+        .default_jumpered_ecp_dma = -1,
+        .kbc_device = NULL,
+        .kbc_p1 = 0xff,
+        .gpio = 0xffffffff,
+        .gpio_acpi = 0xffffffff,
+        .device = NULL,
+        .kbd_device = NULL,
+        .fdc_device = NULL,
+        .sio_device = NULL,
+        .vid_device = NULL,
+        .snd_device = NULL,
+        .net_device = NULL
+    },
     /* Uses some variant of Phoenix MultiKey/42 as the Intel 8242 chip has a Phoenix
        copyright. */
     {