diff --git a/src/chipset/intel_i450kx.c b/src/chipset/intel_i450kx.c
index f4779546c..3435dc8ae 100644
--- a/src/chipset/intel_i450kx.c
+++ b/src/chipset/intel_i450kx.c
@@ -66,9 +66,9 @@ i450kx_log(const char *fmt, ...)
 
 /* SMRAM */
 #define SMRAM_ADDR (((dev->pb_pci_conf[0xb9] << 8) | dev->pb_pci_conf[0xb8]) << 17)
-#define SMRAM_SIZE (1 << (((dev->pb_pci_conf[0xbb] >> 4) + 1) * 16))
 #define SMRAM_ADDR_MC (((dev->mc_pci_conf[0xb9] << 8) | dev->mc_pci_conf[0xb8]) << 16)
-#define SMRAM_SIZE_MC (1 << (((dev->mc_pci_conf[0xbb] >> 4) + 1) * 16))
+#define SMRAM_SIZE (((dev->pb_pci_conf[0xbb] >> 4) + 1) * 64)
+#define SMRAM_SIZE_MC (((dev->mc_pci_conf[0xbb] >> 4) + 1) * 64)
 
 /* Miscellaneous */
 #define ENABLE_SEGMENT (MEM_READ_EXTANY | MEM_WRITE_EXTANY)
@@ -101,10 +101,7 @@ void i450kx_smm(uint32_t smram_addr, uint32_t smram_size, i450kx_t *dev)
     smram_disable_all();
 
     if ((smram_addr != 0) && !!(dev->mc_pci_conf[0x57] & 8))
-    {
         smram_enable(dev->smram, smram_addr, smram_addr, smram_size, !!(dev->pb_pci_conf[0x57] & 8), 1);
-        mem_set_mem_state_smram_ex(1, smram_addr, smram_size, 0x03);
-    }
 
     flushmmucache();
 }
@@ -263,11 +260,7 @@ pb_write(int func, int addr, uint8_t val, void *priv)
     case 0xb8:
     case 0xb9:
     case 0xbb:
-        if (addr == 0xbb)
-            dev->pb_pci_conf[addr] = val & 0xf0;
-        else
-            dev->pb_pci_conf[addr] = val;
-
+        dev->pb_pci_conf[addr] = !(addr == 0xbb) ? val : (val & 0xf0);
         i450kx_smm(SMRAM_ADDR, SMRAM_SIZE, dev);
         break;
 
@@ -324,7 +317,6 @@ mc_write(int func, int addr, uint8_t val, void *priv)
 
     case 0x58:
         dev->mc_pci_conf[addr] = val & 2;
-        mem_set_mem_state_both(0xa0000, 0x20000, (val & 2) ? ENABLE_SEGMENT : DISABLE_SEGMENT);
         break;
 
     case 0x59:
@@ -354,8 +346,8 @@ mc_write(int func, int addr, uint8_t val, void *priv)
     case 0x6d:
     case 0x6e:
     case 0x6f:
-        dev->mc_pci_conf[addr] = ((addr & 0x0f) % 2) ? val : (val & 7);
-        spd_write_drbs(dev->mc_pci_conf, 0x60, 0x6f, 1);
+        dev->mc_pci_conf[addr] = ((addr & 0x0f) % 2) ? 0 : (val & 0x7f);
+        spd_write_drbs(dev->mc_pci_conf, 0x60, 0x6f, 4);
         break;
 
     case 0x74:
@@ -447,10 +439,7 @@ mc_write(int func, int addr, uint8_t val, void *priv)
     case 0xb8:
     case 0xb9:
     case 0xbb:
-        if (addr == 0xbb)
-            dev->mc_pci_conf[addr] = val & 0xf0;
-        else
-            dev->mc_pci_conf[addr] = val;
+        dev->mc_pci_conf[addr] = !(addr == 0xbb) ? val : (val & 0xf0);
 
         i450kx_smm(SMRAM_ADDR_MC, SMRAM_SIZE_MC, dev);
         break;
@@ -500,7 +489,7 @@ i450kx_reset(void *priv)
     dev->pb_pci_conf[0x05] = 4;
     dev->pb_pci_conf[0x06] = 0x40;
     dev->pb_pci_conf[0x07] = 2;
-    dev->pb_pci_conf[0x08] = 1;
+    dev->pb_pci_conf[0x08] = 2;
     dev->pb_pci_conf[0x0b] = 6;
     dev->pb_pci_conf[0x0c] = 8;
     dev->pb_pci_conf[0x0d] = 0x20;
@@ -526,7 +515,7 @@ i450kx_reset(void *priv)
     dev->mc_pci_conf[0x02] = 0xc5;
     dev->mc_pci_conf[0x03] = 0x84;
     dev->mc_pci_conf[0x06] = 0x80;
-    dev->mc_pci_conf[0x08] = 1;
+    dev->mc_pci_conf[0x08] = 4;
     dev->mc_pci_conf[0x0b] = 5;
     dev->mc_pci_conf[0x49] = 0x14;
     dev->mc_pci_conf[0x4c] = 0x0b;
diff --git a/src/chipset/sis_85c496.c b/src/chipset/sis_85c496.c
index f309e3a36..e06dc54c5 100644
--- a/src/chipset/sis_85c496.c
+++ b/src/chipset/sis_85c496.c
@@ -299,7 +299,7 @@ sis_85c49x_pci_write(int func, int addr, uint8_t val, void *priv)
 
 			smram_disable_all();
 
-			if (val & 0x06) {
+			if (val & 0x02) {
 				host_base = 0x00060000;
 				ram_base = 0x000a0000;
 				size = 0x00010000;
@@ -453,6 +453,12 @@ sis_85c49x_pci_read(int func, int addr, void *priv)
     uint8_t ret = dev->pci_conf[addr];
 
     switch (addr) {
+	case 0xa0:
+		ret &= 0x10;
+		break;
+	case 0xa1:
+		ret = 0x00;
+		break;
 	case 0x82: /*Port 22h Mirror*/
 		ret = dev->cur_reg;
 		break;
@@ -517,6 +523,7 @@ sis_85c496_reset(void *priv)
     sis_85c49x_pci_write(0, 0x58, 0x00, dev);
     sis_85c49x_pci_write(0, 0x59, 0x00, dev);
     sis_85c49x_pci_write(0, 0x5a, 0x00, dev);
+    // sis_85c49x_pci_write(0, 0x5a, 0x06, dev);
 
     for (i = 0; i < 8; i++)
 	sis_85c49x_pci_write(0, 0x48 + i, 0x00, dev);
@@ -589,7 +596,7 @@ static void
 
     pci_add_card(PCI_ADD_NORTHBRIDGE, sis_85c49x_pci_read, sis_85c49x_pci_write, dev);
 
-    sis_85c497_isa_reset(dev);
+    // sis_85c497_isa_reset(dev);
 
     dev->port_92 = device_add(&port_92_device);
     port_92_set_period(dev->port_92, 2ULL * TIMER_USEC);
@@ -609,6 +616,8 @@ static void
 
     timer_add(&dev->rmsmiblk_timer, sis_85c496_rmsmiblk_count, dev, 0);
 
+    sis_85c496_reset(dev);
+
     return dev;
 }
 
diff --git a/src/config.c b/src/config.c
index ab42cca31..2b01cf8a5 100644
--- a/src/config.c
+++ b/src/config.c
@@ -450,7 +450,9 @@ load_general(void)
     char temp[512];
     char *p;
 
-    vid_resize = !!config_get_int(cat, "vid_resize", 0);
+    vid_resize = config_get_int(cat, "vid_resize", 0);
+    if (vid_resize & ~3)
+	vid_resize &= 3;
 
     memset(temp, '\0', sizeof(temp));
     p = config_get_string(cat, "vid_renderer", "default");
@@ -488,6 +490,25 @@ load_general(void)
 	window_w = window_h = window_x = window_y = 0;
     }
 
+    if (vid_resize & 2) {
+	p = config_get_string(cat, "window_fixed_res", NULL);
+	if (p == NULL)
+		p = "120x120";
+	sscanf(p, "%ix%i", &fixed_size_x, &fixed_size_y);
+	if (fixed_size_x < 120)
+		fixed_size_x = 120;
+	if (fixed_size_x > 2048)
+		fixed_size_x = 2048;
+	if (fixed_size_y < 120)
+		fixed_size_y = 120;
+	if (fixed_size_y > 2048)
+		fixed_size_y = 2048;
+    } else {
+	config_delete_var(cat, "window_fixed_res");
+
+	fixed_size_x = fixed_size_y = 120;
+    }
+
     sound_gain = config_get_int(cat, "sound_gain", 0);
 
     confirm_reset = config_get_int(cat, "confirm_reset", 1);
@@ -1720,6 +1741,7 @@ config_load(void)
 	fpu_type = fpu_get_type(cpu_f, cpu, "none");
 	gfxcard = video_get_video_from_internal_name("cga");
 	vid_api = plat_vidapi("default");
+	vid_resize = 0;
 	time_sync = TIME_SYNC_ENABLED;
 	hdc_current = hdc_get_from_internal_name("none");
 	serial_enabled[0] = 1;
@@ -1857,6 +1879,12 @@ save_general(void)
 	config_delete_var(cat, "window_coordinates");
     }
 
+    if (vid_resize & 2) {
+	sprintf(temp, "%ix%i", fixed_size_x, fixed_size_y);
+	config_set_string(cat, "window_fixed_res", temp);
+    } else
+	config_delete_var(cat, "window_fixed_res");
+
     if (sound_gain != 0)
 	config_set_int(cat, "sound_gain", sound_gain);
     else
diff --git a/src/cpu/386_common.c b/src/cpu/386_common.c
index 9324976af..5aa1d4b3c 100644
--- a/src/cpu/386_common.c
+++ b/src/cpu/386_common.c
@@ -1027,7 +1027,7 @@ enter_smm(int in_hlt)
     uint32_t smram_state = smbase + 0x10000;
 
     /* If it's a CPU on which SMM is not supported, do nothing. */
-    if (!is_am486 && !is_pentium && !is_k5 && !is_k6 && !is_p6 && !is_cx6x86)
+    if (!is_am486 && !is_pentium && !is_k5 && !is_k6 && !is_p6 && !is_cxsmm)
 	return;
 
     x386_common_log("enter_smm(): smbase = %08X\n", smbase);
@@ -1066,7 +1066,7 @@ enter_smm(int in_hlt)
     smram_backup_all();
     smram_recalc_all(0);
 
-    if (cpu_iscyrix) {
+    if (is_cxsmm) {
 	if (!(cyrix.smhr & SMHR_VALID))
 		cyrix.smhr = (cyrix.arr[3].base + cyrix.arr[3].size) | SMHR_VALID;
 	smram_state = cyrix.smhr & SMHR_ADDR_MASK;
@@ -1074,11 +1074,11 @@ enter_smm(int in_hlt)
 
     memset(saved_state, 0x00, SMM_SAVE_STATE_MAP_SIZE * sizeof(uint32_t));
 
-    if (cpu_iscyrix)			/* Cx6x86 */
+    if (is_cxsmm)			/* Cx6x86 */
 	smram_save_state_cyrix(saved_state, in_hlt);
-    if (is_pentium || is_am486)		/* Am486 / 5x86 / Intel P5 (Pentium) */
+    else if (is_pentium || is_am486)	/* Am486 / 5x86 / Intel P5 (Pentium) */
 	smram_save_state_p5(saved_state, in_hlt);
-    else if (is_k5 || is_k6)	/* AMD K5 and K6 */
+    else if (is_k5 || is_k6)		/* AMD K5 and K6 */
 	smram_save_state_amd_k(saved_state, in_hlt);
     else if (is_p6)			/* Intel P6 (Pentium Pro, Pentium II, Celeron) */
 	smram_save_state_p6(saved_state, in_hlt);
@@ -1091,8 +1091,11 @@ enter_smm(int in_hlt)
 
     dr[7] = 0x400;
 
-    if (cpu_iscyrix) {
+    if (is_cxsmm) {
 	cpu_state.pc = 0x0000;
+	cpl_override = 1;
+	cyrix_write_seg_descriptor(smram_state - 0x20, &cpu_state.seg_cs);
+	cpl_override = 0;
 	cpu_state.seg_cs.seg = (cyrix.arr[3].base >> 4);
 	cpu_state.seg_cs.base = cyrix.arr[3].base;
 	cpu_state.seg_cs.limit = 0xffffffff;
@@ -1137,15 +1140,14 @@ enter_smm(int in_hlt)
     cpu_state.op32 = use32;
 
     cpl_override = 1;
-    if (cpu_iscyrix) {
+    if (is_cxsmm) {
 	writememl(0, smram_state - 0x04, saved_state[0]);
 	writememl(0, smram_state - 0x08, saved_state[1]);
 	writememl(0, smram_state - 0x0c, saved_state[2]);
 	writememl(0, smram_state - 0x10, saved_state[3]);
 	writememl(0, smram_state - 0x14, saved_state[4]);
 	writememl(0, smram_state - 0x18, saved_state[5]);
-	cyrix_write_seg_descriptor(smram_state - 0x20, &cpu_state.seg_cs);
-	writememl(0, smram_state - 0x18, saved_state[6]);
+	writememl(0, smram_state - 0x24, saved_state[6]);
     } else {
 	for (n = 0; n < SMM_SAVE_STATE_MAP_SIZE; n++) {
 		smram_state -= 4;
@@ -1214,13 +1216,13 @@ leave_smm(void)
     uint32_t smram_state = smbase + 0x10000;
 
     /* If it's a CPU on which SMM is not supported (or not implemented in 86Box), do nothing. */
-    if (!is_am486 && !is_pentium && !is_k5 && !is_k6 && !is_p6 && !is_cx6x86)
+    if (!is_am486 && !is_pentium && !is_k5 && !is_k6 && !is_p6 && !is_cxsmm)
 	return;
 
     memset(saved_state, 0x00, SMM_SAVE_STATE_MAP_SIZE * sizeof(uint32_t));
 
     cpl_override = 1;
-    if (cpu_iscyrix) {
+    if (is_cxsmm) {
 	smram_state = cyrix.smhr & SMHR_ADDR_MASK;
 	saved_state[0] = readmeml(0, smram_state - 0x04);
 	saved_state[1] = readmeml(0, smram_state - 0x08);
@@ -1246,13 +1248,13 @@ leave_smm(void)
     }
 
     x386_common_log("New SMBASE: %08X (%08X)\n", saved_state[SMRAM_FIELD_P5_SMBASE_OFFSET], saved_state[66]);
-    if (cpu_iscyrix)		/* Cx6x86 */
+    if (is_cxsmm)			/* Cx6x86 */
 	smram_restore_state_cyrix(saved_state);
-    else if (is_pentium)	/* Intel P5 (Pentium) */
+    else if (is_pentium || is_am486)	/* Am486 / 5x86 / Intel P5 (Pentium) */
 	smram_restore_state_p5(saved_state);
-    else if (is_k5 || is_k6)	/* AMD K5 and K6 */
+    else if (is_k5 || is_k6)		/* AMD K5 and K6 */
 	smram_restore_state_amd_k(saved_state);
-    else if (is_p6)		/* Intel P6 (Pentium Pro, Pentium II, Celeron) */
+    else if (is_p6)			/* Intel P6 (Pentium Pro, Pentium II, Celeron) */
 	smram_restore_state_p6(saved_state);
 
     in_smm = 0;
@@ -1637,7 +1639,6 @@ sysenter(uint32_t fetchdat)
     cpu_state.seg_cs.base = 0;
     cpu_state.seg_cs.limit_low = 0;
     cpu_state.seg_cs.limit = 0xffffffff;
-    cpu_state.seg_cs.limit_raw = 0x000fffff;
     cpu_state.seg_cs.limit_high = 0xffffffff;
     cpu_state.seg_cs.access = 0x9b;
     cpu_state.seg_cs.ar_high = 0xcf;
@@ -1648,7 +1649,6 @@ sysenter(uint32_t fetchdat)
     cpu_state.seg_ss.base = 0;
     cpu_state.seg_ss.limit_low = 0;
     cpu_state.seg_ss.limit = 0xffffffff;
-    cpu_state.seg_ss.limit_raw = 0x000fffff;
     cpu_state.seg_ss.limit_high = 0xffffffff;
     cpu_state.seg_ss.access = 0x93;
     cpu_state.seg_ss.ar_high = 0xcf;
@@ -1726,7 +1726,6 @@ sysexit(uint32_t fetchdat)
     cpu_state.seg_cs.base = 0;
     cpu_state.seg_cs.limit_low = 0;
     cpu_state.seg_cs.limit = 0xffffffff;
-    cpu_state.seg_cs.limit_raw = 0x000fffff;
     cpu_state.seg_cs.limit_high = 0xffffffff;
     cpu_state.seg_cs.access = 0xfb;
     cpu_state.seg_cs.ar_high = 0xcf;
@@ -1737,7 +1736,6 @@ sysexit(uint32_t fetchdat)
     cpu_state.seg_ss.base = 0;
     cpu_state.seg_ss.limit_low = 0;
     cpu_state.seg_ss.limit = 0xffffffff;
-    cpu_state.seg_ss.limit_raw = 0x000fffff;
     cpu_state.seg_ss.limit_high = 0xffffffff;
     cpu_state.seg_ss.access = 0xf3;
     cpu_state.seg_ss.ar_high = 0xcf;
@@ -1789,7 +1787,6 @@ syscall_op(uint32_t fetchdat)
     cpu_state.seg_cs.base = 0;
     cpu_state.seg_cs.limit_low = 0;
     cpu_state.seg_cs.limit = 0xffffffff;
-    cpu_state.seg_cs.limit_raw = 0x000fffff;
     cpu_state.seg_cs.limit_high = 0xffffffff;
     cpu_state.seg_cs.access = 0x9b;
     cpu_state.seg_cs.ar_high = 0xcf;
@@ -1801,7 +1798,6 @@ syscall_op(uint32_t fetchdat)
     cpu_state.seg_ss.base = 0;
     cpu_state.seg_ss.limit_low = 0;
     cpu_state.seg_ss.limit = 0xffffffff;
-    cpu_state.seg_ss.limit_raw = 0x000fffff;
     cpu_state.seg_ss.limit_high = 0xffffffff;
     cpu_state.seg_ss.access = 0x93;
     cpu_state.seg_ss.ar_high = 0xcf;
@@ -1852,7 +1848,6 @@ sysret(uint32_t fetchdat)
     cpu_state.seg_cs.base = 0;
     cpu_state.seg_cs.limit_low = 0;
     cpu_state.seg_cs.limit = 0xffffffff;
-    cpu_state.seg_cs.limit_raw = 0x000fffff;
     cpu_state.seg_cs.limit_high = 0xffffffff;
     cpu_state.seg_cs.access = 0xfb;
     cpu_state.seg_cs.ar_high = 0xcf;
@@ -1864,7 +1859,6 @@ sysret(uint32_t fetchdat)
     cpu_state.seg_ss.base = 0;
     cpu_state.seg_ss.limit_low = 0;
     cpu_state.seg_ss.limit = 0xffffffff;
-    cpu_state.seg_ss.limit_raw = 0x000fffff;
     cpu_state.seg_ss.limit_high = 0xffffffff;
     cpu_state.seg_ss.access = 0xf3;
     cpu_state.seg_cs.ar_high = 0xcf;
diff --git a/src/cpu/386_ops.h b/src/cpu/386_ops.h
index acfbb8532..a66913a4f 100644
--- a/src/cpu/386_ops.h
+++ b/src/cpu/386_ops.h
@@ -170,9 +170,7 @@ extern void	x386_dynarec_log(const char *fmt, ...);
 #include "x86_ops_bcd.h"
 #include "x86_ops_bit.h"
 #include "x86_ops_bitscan.h"
-#if defined(DEV_BRANCH) && defined(USE_CYRIX_6X86)
 #include "x86_ops_cyrix.h"
-#endif
 #include "x86_ops_flag.h"
 #include "x86_ops_fpu.h"
 #include "x86_ops_inc_dec.h"
@@ -635,6 +633,98 @@ const OpFn OP_TABLE(486_0f)[1024] =
 /*e0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
 /*f0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
 };
+
+const OpFn OP_TABLE(c486_0f)[1024] = 
+{
+        /*16-bit data, 16-bit addr*/
+/*      00              01              02              03              04              05              06              07              08              09              0a              0b              0c              0d              0e              0f*/        
+/*00*/  op0F00_a16,     op0F01_w_a16,   opLAR_w_a16,    opLSL_w_a16,    ILLEGAL,        ILLEGAL,        opCLTS,         opLOADALL386,   opINVD,         opWBINVD,       ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*10*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*20*/  opMOV_r_CRx_a16,opMOV_r_DRx_a16,opMOV_CRx_r_a16,opMOV_DRx_r_a16,opMOV_r_TRx_a16,ILLEGAL,        opMOV_TRx_r_a16,ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*30*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opRDSHR_a16,    opWRSHR_a16,    ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+/*40*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*50*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*60*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*70*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opSVDC_a16,     opRSDC_a16,     opSVLDT_a16,    opRSLDT_a16,    opSVTS_a16,     opRSTS_a16,     ILLEGAL,        ILLEGAL,
+
+/*80*/  opJO_w,         opJNO_w,        opJB_w,         opJNB_w,        opJE_w,         opJNE_w,        opJBE_w,        opJNBE_w,       opJS_w,         opJNS_w,        opJP_w,         opJNP_w,        opJL_w,         opJNL_w,        opJLE_w,        opJNLE_w,
+/*90*/  opSETO_a16,     opSETNO_a16,    opSETB_a16,     opSETNB_a16,    opSETE_a16,     opSETNE_a16,    opSETBE_a16,    opSETNBE_a16,   opSETS_a16,     opSETNS_a16,    opSETP_a16,     opSETNP_a16,    opSETL_a16,     opSETNL_a16,    opSETLE_a16,    opSETNLE_a16,
+/*a0*/  opPUSH_FS_w,    opPOP_FS_w,     opCPUID,        opBT_w_r_a16,   opSHLD_w_i_a16, opSHLD_w_CL_a16,ILLEGAL,        ILLEGAL,        opPUSH_GS_w,    opPOP_GS_w,     opRSM,          opBTS_w_r_a16,  opSHRD_w_i_a16, opSHRD_w_CL_a16,ILLEGAL,        opIMUL_w_w_a16,
+/*b0*/  opCMPXCHG_b_a16,opCMPXCHG_w_a16,opLSS_w_a16,    opBTR_w_r_a16,  opLFS_w_a16,    opLGS_w_a16,    opMOVZX_w_b_a16,opMOVZX_w_w_a16,ILLEGAL,        ILLEGAL,        opBA_w_a16,     opBTC_w_r_a16,  opBSF_w_a16,    opBSR_w_a16,    opMOVSX_w_b_a16,ILLEGAL,
+
+/*c0*/  opXADD_b_a16,   opXADD_w_a16,   ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opBSWAP_EAX,    opBSWAP_ECX,    opBSWAP_EDX,    opBSWAP_EBX,    opBSWAP_ESP,    opBSWAP_EBP,    opBSWAP_ESI,    opBSWAP_EDI,
+/*d0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*e0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*f0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+        /*32-bit data, 16-bit addr*/
+/*      00              01              02              03              04              05              06              07              08              09              0a              0b              0c              0d              0e              0f*/        
+/*00*/  op0F00_a16,     op0F01_l_a16,   opLAR_l_a16,    opLSL_l_a16,    ILLEGAL,        ILLEGAL,        opCLTS,         opLOADALL386,   opINVD,         opWBINVD,       ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*10*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*20*/  opMOV_r_CRx_a16,opMOV_r_DRx_a16,opMOV_CRx_r_a16,opMOV_DRx_r_a16,opMOV_r_TRx_a16,ILLEGAL,        opMOV_TRx_r_a16,ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*30*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opRDSHR_a16,    opWRSHR_a16,    opSVDC_a16,     opRSDC_a16,     opSVLDT_a16,    opRSLDT_a16,    opSVTS_a16,     opRSTS_a16,     ILLEGAL,        ILLEGAL,
+
+/*40*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*50*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*60*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*70*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+/*80*/  opJO_l,         opJNO_l,        opJB_l,         opJNB_l,        opJE_l,         opJNE_l,        opJBE_l,        opJNBE_l,       opJS_l,         opJNS_l,        opJP_l,         opJNP_l,        opJL_l,         opJNL_l,        opJLE_l,        opJNLE_l,
+/*90*/  opSETO_a16,     opSETNO_a16,    opSETB_a16,     opSETNB_a16,    opSETE_a16,     opSETNE_a16,    opSETBE_a16,    opSETNBE_a16,   opSETS_a16,     opSETNS_a16,    opSETP_a16,     opSETNP_a16,    opSETL_a16,     opSETNL_a16,    opSETLE_a16,    opSETNLE_a16,
+/*a0*/  opPUSH_FS_l,    opPOP_FS_l,     opCPUID,        opBT_l_r_a16,   opSHLD_l_i_a16, opSHLD_l_CL_a16,ILLEGAL,        ILLEGAL,        opPUSH_GS_l,    opPOP_GS_l,     opRSM,          opBTS_l_r_a16,  opSHRD_l_i_a16, opSHRD_l_CL_a16,ILLEGAL,        opIMUL_l_l_a16,
+/*b0*/  opCMPXCHG_b_a16,opCMPXCHG_l_a16,opLSS_l_a16,    opBTR_l_r_a16,  opLFS_l_a16,    opLGS_l_a16,    opMOVZX_l_b_a16,opMOVZX_l_w_a16,ILLEGAL,        ILLEGAL,        opBA_l_a16,     opBTC_l_r_a16,  opBSF_l_a16,    opBSR_l_a16,    opMOVSX_l_b_a16,opMOVSX_l_w_a16,
+
+/*c0*/  opXADD_b_a16,   opXADD_l_a16,   ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opBSWAP_EAX,    opBSWAP_ECX,    opBSWAP_EDX,    opBSWAP_EBX,    opBSWAP_ESP,    opBSWAP_EBP,    opBSWAP_ESI,    opBSWAP_EDI,
+/*d0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*e0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*f0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+        /*16-bit data, 32-bit addr*/
+/*      00              01              02              03              04              05              06              07              08              09              0a              0b              0c              0d              0e              0f*/        
+/*00*/  op0F00_a32,     op0F01_w_a32,   opLAR_w_a32,    opLSL_w_a32,    ILLEGAL,        ILLEGAL,        opCLTS,         opLOADALL386,   opINVD,         opWBINVD,       ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*10*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*20*/  opMOV_r_CRx_a32,opMOV_r_DRx_a32,opMOV_CRx_r_a32,opMOV_DRx_r_a32,opMOV_r_TRx_a32,ILLEGAL,        opMOV_TRx_r_a32,ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*30*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opRDSHR_a32,    opWRSHR_a32,    ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+/*40*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*50*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*60*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*70*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opSVDC_a32,     opRSDC_a32,     opSVLDT_a32,    opRSLDT_a32,    opSVTS_a32,     opRSTS_a32,     ILLEGAL,        ILLEGAL,
+
+/*80*/  opJO_w,         opJNO_w,        opJB_w,         opJNB_w,        opJE_w,         opJNE_w,        opJBE_w,        opJNBE_w,       opJS_w,         opJNS_w,        opJP_w,         opJNP_w,        opJL_w,         opJNL_w,        opJLE_w,        opJNLE_w,
+/*90*/  opSETO_a32,     opSETNO_a32,    opSETB_a32,     opSETNB_a32,    opSETE_a32,     opSETNE_a32,    opSETBE_a32,    opSETNBE_a32,   opSETS_a32,     opSETNS_a32,    opSETP_a32,     opSETNP_a32,    opSETL_a32,     opSETNL_a32,    opSETLE_a32,    opSETNLE_a32,
+/*a0*/  opPUSH_FS_w,    opPOP_FS_w,     opCPUID,        opBT_w_r_a32,   opSHLD_w_i_a32, opSHLD_w_CL_a32,ILLEGAL,        ILLEGAL,        opPUSH_GS_w,    opPOP_GS_w,     opRSM,          opBTS_w_r_a32,  opSHRD_w_i_a32, opSHRD_w_CL_a32,ILLEGAL,        opIMUL_w_w_a32,
+/*b0*/  opCMPXCHG_b_a32,opCMPXCHG_w_a32,opLSS_w_a32,    opBTR_w_r_a32,  opLFS_w_a32,    opLGS_w_a32,    opMOVZX_w_b_a32,opMOVZX_w_w_a32,ILLEGAL,        ILLEGAL,        opBA_w_a32,     opBTC_w_r_a32,  opBSF_w_a32,    opBSR_w_a32,    opMOVSX_w_b_a32,ILLEGAL,
+
+/*c0*/  opXADD_b_a32,   opXADD_w_a32,   ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opBSWAP_EAX,    opBSWAP_ECX,    opBSWAP_EDX,    opBSWAP_EBX,    opBSWAP_ESP,    opBSWAP_EBP,    opBSWAP_ESI,    opBSWAP_EDI,
+/*d0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*e0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*f0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+        /*32-bit data, 32-bit addr*/
+/*      00              01              02              03              04              05              06              07              08              09              0a              0b              0c              0d              0e              0f*/        
+/*00*/  op0F00_a32,     op0F01_l_a32,   opLAR_l_a32,    opLSL_l_a32,    ILLEGAL,        ILLEGAL,        opCLTS,         opLOADALL386,   opINVD,         opWBINVD,       ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*10*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*20*/  opMOV_r_CRx_a32,opMOV_r_DRx_a32,opMOV_CRx_r_a32,opMOV_DRx_r_a32,opMOV_r_TRx_a32,ILLEGAL,        opMOV_TRx_r_a32,ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*30*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opRDSHR_a32,    opWRSHR_a32,    ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+
+/*40*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*50*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*60*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*70*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opSVDC_a16,     opRSDC_a16,     opSVLDT_a16,    opRSLDT_a16,    opSVTS_a16,     opRSTS_a16,     ILLEGAL,        ILLEGAL,
+
+/*80*/  opJO_l,         opJNO_l,        opJB_l,         opJNB_l,        opJE_l,         opJNE_l,        opJBE_l,        opJNBE_l,       opJS_l,         opJNS_l,        opJP_l,         opJNP_l,        opJL_l,         opJNL_l,        opJLE_l,        opJNLE_l,
+/*90*/  opSETO_a32,     opSETNO_a32,    opSETB_a32,     opSETNB_a32,    opSETE_a32,     opSETNE_a32,    opSETBE_a32,    opSETNBE_a32,   opSETS_a32,     opSETNS_a32,    opSETP_a32,     opSETNP_a32,    opSETL_a32,     opSETNL_a32,    opSETLE_a32,    opSETNLE_a32,
+/*a0*/  opPUSH_FS_l,    opPOP_FS_l,     opCPUID,        opBT_l_r_a32,   opSHLD_l_i_a32, opSHLD_l_CL_a32,ILLEGAL,        ILLEGAL,        opPUSH_GS_l,    opPOP_GS_l,     opRSM,          opBTS_l_r_a32,  opSHRD_l_i_a32, opSHRD_l_CL_a32,ILLEGAL,        opIMUL_l_l_a32,
+/*b0*/  opCMPXCHG_b_a32,opCMPXCHG_l_a32,opLSS_l_a32,    opBTR_l_r_a32,  opLFS_l_a32,    opLGS_l_a32,    opMOVZX_l_b_a32,opMOVZX_l_w_a32,ILLEGAL,        ILLEGAL,        opBA_l_a32,     opBTC_l_r_a32,  opBSF_l_a32,    opBSR_l_a32,    opMOVSX_l_b_a32,opMOVSX_l_w_a32,
+
+/*c0*/  opXADD_b_a32,   opXADD_l_a32,   ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        opBSWAP_EAX,    opBSWAP_ECX,    opBSWAP_EDX,    opBSWAP_EBX,    opBSWAP_ESP,    opBSWAP_EBP,    opBSWAP_ESI,    opBSWAP_EDI,
+/*d0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*e0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+/*f0*/  ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,        ILLEGAL,
+};
+
 const OpFn OP_TABLE(ibm486_0f)[1024] = 
 {
         /*16-bit data, 16-bit addr*/
diff --git a/src/cpu/cpu.c b/src/cpu/cpu.c
index 4f31ab5ad..191754d7f 100644
--- a/src/cpu/cpu.c
+++ b/src/cpu/cpu.c
@@ -110,7 +110,7 @@ int		isa_cycles,
 
  		is286, is386, is486 = 1, is486sx, is486dx, is486sx2, is486dx2, isdx4,
 		cpu_isintel, cpu_iscyrix, hascache, isibm486, israpidcad, is_vpc,
-		is_am486, is_pentium, is_k5, is_k6, is_p6, is_cx6x86, hasfpu,
+		is_am486, is_486_org, is_pentium, is_k5, is_k6, is_p6, is_cxsmm, hasfpu,
 
 		timing_rr, timing_mr, timing_mrl, timing_rm, timing_rml,
 		timing_mm, timing_mml, timing_bt, timing_bnt,
@@ -373,6 +373,8 @@ cpu_set(void)
     is486dx      = (cpu_s->cpu_type >= CPU_i486DX) && (cpu_s->cpu_type < CPU_i486DX2);
     is486dx2     = (cpu_s->cpu_type >= CPU_i486DX2) && (cpu_s->cpu_type < CPU_iDX4);	
     isdx4        = (cpu_s->cpu_type >= CPU_iDX4) && (cpu_s->cpu_type < CPU_WINCHIP);
+    is_486_org   = (cpu_s->cpu_type == CPU_i486SX) || (cpu_s->cpu_type == CPU_i486DX) ||
+		   (cpu_s->cpu_type == CPU_Am486SX) || (cpu_s->cpu_type == CPU_Am486DX);
     is_am486     = !strcmp(cpu_f->manufacturer, "AMD") && (cpu_s->cpu_type >= CPU_Am486SX) && (cpu_s->cpu_type <= CPU_Am5x86);
 
     cpu_isintel = !strcmp(cpu_f->manufacturer, "Intel");
@@ -380,13 +382,13 @@ cpu_set(void)
 
     /* The 486DX2 and iDX4 have the same SMM save state table layout as Pentiums,
        and the WinChip datasheet claims those are Pentium-compatible as well. */
-    is_pentium   = (cpu_isintel && (cpu_s->cpu_type >= CPU_i486DX2) && (cpu_s->cpu_type < CPU_PENTIUMPRO)) ||
+    is_pentium   = (cpu_isintel && (cpu_s->cpu_type >= CPU_i486SX) && (cpu_s->cpu_type < CPU_PENTIUMPRO)) ||
 		   !strcmp(cpu_f->manufacturer, "IDT");
     is_k5        = !strcmp(cpu_f->manufacturer, "AMD") && (cpu_s->cpu_type > CPU_Am5x86);
     is_k6        = (cpu_s->cpu_type >= CPU_K6) && !strcmp(cpu_f->manufacturer, "AMD");
     /* The Samuel 2 datasheet claims it's Celeron-compatible. */
     is_p6        = (cpu_isintel && (cpu_s->cpu_type >= CPU_PENTIUMPRO)) || !strcmp(cpu_f->manufacturer, "VIA");
-    is_cx6x86    = !strcmp(cpu_f->manufacturer, "Cyrix") && (cpu_s->cpu_type > CPU_Cx5x86);
+    is_cxsmm     = !strcmp(cpu_f->manufacturer, "Cyrix") && (cpu_s->cpu_type >= CPU_Cx486S);
 
     hasfpu       = (fpu_type != FPU_NONE);
     hascache     = (cpu_s->cpu_type >= CPU_486SLC) || (cpu_s->cpu_type == CPU_IBM386SLC) ||
@@ -816,9 +818,9 @@ cpu_set(void)
 	case CPU_Cx486DX2:
 	case CPU_Cx486DX4:
 #ifdef USE_DYNAREC
-		x86_setopcodes(ops_386, ops_486_0f, dynarec_ops_386, dynarec_ops_486_0f);
+		x86_setopcodes(ops_386, ops_c486_0f, dynarec_ops_386, dynarec_ops_c486_0f);
 #else
-		x86_setopcodes(ops_386, ops_486_0f);
+		x86_setopcodes(ops_386, ops_c486_0f);
 #endif
 
                 timing_rr			=   1;	/* register dest - register src */
@@ -856,9 +858,9 @@ cpu_set(void)
 
 	case CPU_Cx5x86:
 #ifdef USE_DYNAREC
-		x86_setopcodes(ops_386, ops_486_0f, dynarec_ops_386, dynarec_ops_486_0f);
+		x86_setopcodes(ops_386, ops_c486_0f, dynarec_ops_386, dynarec_ops_c486_0f);
 #else
-		x86_setopcodes(ops_386, ops_486_0f);
+		x86_setopcodes(ops_386, ops_c486_0f);
 #endif
 
 		timing_rr			=   1;	/* register dest - register src */
@@ -1027,7 +1029,6 @@ cpu_set(void)
   	case CPU_Cx6x86MX:
 		if (cpu_s->cpu_type == CPU_Cx6x86MX) {
 #ifdef USE_DYNAREC
-			x86_setopcodes(ops_386, ops_c6x86mx_0f, dynarec_ops_386, dynarec_ops_c6x86mx_0f);
 			x86_dynarec_opcodes_da_a16 = dynarec_ops_fpu_686_da_a16;
 			x86_dynarec_opcodes_da_a32 = dynarec_ops_fpu_686_da_a32;
 			x86_dynarec_opcodes_db_a16 = dynarec_ops_fpu_686_db_a16;
@@ -1049,7 +1050,8 @@ cpu_set(void)
 		else if (cpu_s->cpu_type == CPU_Cx6x86L)
 			x86_setopcodes(ops_386, ops_pentium_0f, dynarec_ops_386, dynarec_ops_pentium_0f);
 		else
-			x86_setopcodes(ops_386, ops_c6x86_0f, dynarec_ops_386, dynarec_ops_c6x86_0f);
+			x86_setopcodes(ops_386, ops_c6x86mx_0f, dynarec_ops_386, dynarec_ops_c6x86mx_0f);
+			// x86_setopcodes(ops_386, ops_c6x86_0f, dynarec_ops_386, dynarec_ops_c6x86_0f);
 #else
 		if (cpu_s->cpu_type == CPU_Cx6x86MX)
 			x86_setopcodes(ops_386, ops_c6x86mx_0f);
diff --git a/src/cpu/cpu.h b/src/cpu/cpu.h
index 2ebd1362e..2a9996a06 100644
--- a/src/cpu/cpu.h
+++ b/src/cpu/cpu.h
@@ -218,8 +218,7 @@ typedef struct {
     uint8_t	access, ar_high;
     int8_t	checked; /*Non-zero if selector is known to be valid*/
     uint16_t	seg;
-    uint32_t	base,
-		limit, limit_raw,
+    uint32_t	base, limit,
 		limit_low, limit_high;
 } x86seg;
 
@@ -484,7 +483,7 @@ extern int	cpu_cyrix_alignment;	/*Cyrix 5x86/6x86 only has data misalignment
 					  penalties when crossing 8-byte boundaries*/
 
 extern int	is8086,	is286, is386, is486, is486sx, is486dx, is486sx2, is486dx2, isdx4;
-extern int	is_am486, is_pentium, is_k5, is_k6, is_p6, is_cx6x86;
+extern int	is_am486, is_486_org, is_pentium, is_k5, is_k6, is_p6, is_cxsmm;
 extern int	hascache;
 extern int	isibm486;
 extern int	is_rapidcad;
diff --git a/src/cpu/x86.c b/src/cpu/x86.c
index 70ef37701..f8e13764e 100644
--- a/src/cpu/x86.c
+++ b/src/cpu/x86.c
@@ -281,7 +281,7 @@ reset_common(int hard)
     smi_block = 0;
 
     if (hard) {
-	smbase = 0x00030000;
+	smbase = is_486_org ? 0x00060000 : 0x00030000;
 	ppi_reset();
     }
     in_sys = 0;
diff --git a/src/cpu/x86_ops.h b/src/cpu/x86_ops.h
index 1e81b386a..dc0d62782 100644
--- a/src/cpu/x86_ops.h
+++ b/src/cpu/x86_ops.h
@@ -79,6 +79,7 @@ extern const OpFn dynarec_ops_386[1024];
 extern const OpFn dynarec_ops_386_0f[1024];
 
 extern const OpFn dynarec_ops_486_0f[1024];
+extern const OpFn dynarec_ops_c486_0f[1024];
 extern const OpFn dynarec_ops_ibm486_0f[1024];
 
 extern const OpFn dynarec_ops_winchip_0f[1024];
@@ -176,6 +177,7 @@ extern const OpFn ops_386[1024];
 extern const OpFn ops_386_0f[1024];
 
 extern const OpFn ops_486_0f[1024];
+extern const OpFn ops_c486_0f[1024];
 extern const OpFn ops_ibm486_0f[1024];
 
 extern const OpFn ops_winchip_0f[1024];
diff --git a/src/cpu/x86_ops_cyrix.h b/src/cpu/x86_ops_cyrix.h
index e6464ce84..500b119fb 100644
--- a/src/cpu/x86_ops_cyrix.h
+++ b/src/cpu/x86_ops_cyrix.h
@@ -29,13 +29,12 @@ static void opSVDC_common(uint32_t fetchdat)
                 writememw(0, easeg+cpu_state.eaaddr+8, GS);
                 break;
                 default:
-                pclog("opSVDC: unknown rmdat %02x\n", rmdat);
                 x86illegal();
         }
 }
 static int opSVDC_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_16(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -48,7 +47,7 @@ static int opSVDC_a16(uint32_t fetchdat)
 }
 static int opSVDC_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_32(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -80,13 +79,12 @@ static void opRSDC_common(uint32_t fetchdat)
                 cyrix_load_seg_descriptor(easeg+cpu_state.eaaddr, &cpu_state.seg_gs);
                 break;
                 default:
-                pclog("opRSDC: unknown rmdat %02x\n", rmdat);
                 x86illegal();
         }
 }
 static int opRSDC_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_16(fetchdat);
                 SEG_CHECK_READ(cpu_state.ea_seg);
@@ -99,7 +97,7 @@ static int opRSDC_a16(uint32_t fetchdat)
 }
 static int opRSDC_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_32(fetchdat);
                 SEG_CHECK_READ(cpu_state.ea_seg);
@@ -113,7 +111,7 @@ static int opRSDC_a32(uint32_t fetchdat)
 
 static int opSVLDT_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_16(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -127,7 +125,7 @@ static int opSVLDT_a16(uint32_t fetchdat)
 }
 static int opSVLDT_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_32(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -142,7 +140,7 @@ static int opSVLDT_a32(uint32_t fetchdat)
 
 static int opRSLDT_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_16(fetchdat);
                 SEG_CHECK_READ(cpu_state.ea_seg);
@@ -155,7 +153,7 @@ static int opRSLDT_a16(uint32_t fetchdat)
 }
 static int opRSLDT_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_32(fetchdat);
                 SEG_CHECK_READ(cpu_state.ea_seg);
@@ -169,7 +167,7 @@ static int opRSLDT_a32(uint32_t fetchdat)
 
 static int opSVTS_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_16(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -183,7 +181,7 @@ static int opSVTS_a16(uint32_t fetchdat)
 }
 static int opSVTS_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_32(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -198,7 +196,7 @@ static int opSVTS_a32(uint32_t fetchdat)
 
 static int opRSTS_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_16(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -212,7 +210,7 @@ static int opRSTS_a16(uint32_t fetchdat)
 }
 static int opRSTS_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
         {
                 fetch_ea_32(fetchdat);
                 SEG_CHECK_WRITE(cpu_state.ea_seg);
@@ -227,7 +225,7 @@ static int opRSTS_a32(uint32_t fetchdat)
 
 static int opSMINT(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
                 fatal("opSMINT\n");
         else
                 x86illegal();
@@ -237,7 +235,7 @@ static int opSMINT(uint32_t fetchdat)
 
 static int opRDSHR_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
                 fatal("opRDSHR_a16\n");
         else
                 x86illegal();
@@ -246,7 +244,7 @@ static int opRDSHR_a16(uint32_t fetchdat)
 }
 static int opRDSHR_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
                 fatal("opRDSHR_a32\n");
         else
                 x86illegal();
@@ -256,7 +254,7 @@ static int opRDSHR_a32(uint32_t fetchdat)
 
 static int opWRSHR_a16(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
                 fatal("opWRSHR_a16\n");
         else
                 x86illegal();
@@ -265,7 +263,7 @@ static int opWRSHR_a16(uint32_t fetchdat)
 }
 static int opWRSHR_a32(uint32_t fetchdat)
 {
-        if (cpu_cur_status & CPU_STATUS_SMM)
+        if (in_smm)
                 fatal("opWRSHR_a32\n");
         else
                 x86illegal();
diff --git a/src/cpu/x86_ops_pmode.h b/src/cpu/x86_ops_pmode.h
index b372da126..b031fac22 100644
--- a/src/cpu/x86_ops_pmode.h
+++ b/src/cpu/x86_ops_pmode.h
@@ -198,7 +198,6 @@ static int op0F00_common(uint32_t fetchdat, int ea32)
                 granularity = readmemb(0, addr + 6) & 0x80;
                 if (cpu_state.abrt) return 1;
                 ldt.limit = limit;
-                ldt.limit_raw = limit;
                 ldt.access = access;
                 ldt.ar_high = ar_high;
                 if (granularity)
@@ -232,7 +231,6 @@ static int op0F00_common(uint32_t fetchdat, int ea32)
                 if (cpu_state.abrt) return 1;
                 tr.seg = sel;
                 tr.limit = limit;
-                tr.limit_raw = limit;
                 tr.access = access;
                 tr.ar_high = ar_high;
                 if (granularity)
diff --git a/src/cpu/x86seg.c b/src/cpu/x86seg.c
index a9c3923c8..763ca1358 100644
--- a/src/cpu/x86seg.c
+++ b/src/cpu/x86seg.c
@@ -227,7 +227,6 @@ void
 do_seg_load(x86seg *s, uint16_t *segdat)
 {
     s->limit = segdat[0] | ((segdat[3] & 0x000f) << 16);
-    s->limit_raw = s->limit;
     if (segdat[3] & 0x0080)
 	s->limit = (s->limit << 12) | 0xfff;
     s->base = segdat[1] | ((segdat[2] & 0x00ff) << 16);
@@ -2382,9 +2381,14 @@ taskswitch286(uint16_t seg, uint16_t *segdat, int is32)
 void
 cyrix_write_seg_descriptor(uint32_t addr, x86seg *seg)
 {
-    writememl(0, addr, (seg->limit_raw & 0xffff) | (seg->base << 16));
+    uint32_t limit_raw = seg->limit;
+
+    if (seg->ar_high & 0x80)
+	limit_raw >>= 12;
+
+    writememl(0, addr, (limit_raw & 0xffff) | (seg->base << 16));
     writememl(0, addr + 4, ((seg->base >> 16) & 0xff) | (seg->access << 8) |
-	      (seg->limit_raw & 0xf0000) | (seg->ar_high << 16) |
+	      (limit_raw & 0xf0000) | (seg->ar_high << 16) |
 	      (seg->base & 0xff000000));
 }
 
diff --git a/src/device/keyboard_at.c b/src/device/keyboard_at.c
index f6b9f7be0..600c61bb4 100644
--- a/src/device/keyboard_at.c
+++ b/src/device/keyboard_at.c
@@ -1061,7 +1061,7 @@ write_output(atkbd_t *dev, uint8_t val)
 		/* Pin 0 selected. */
 		softresetx86(); /*Pulse reset!*/
 		cpu_set_edx();
-		smbase = 0x00030000;
+		smbase = is_486_org ? 0x00060000 : 0x00030000;
 	}
     }
     /* Mask off the A20 stuff because we use mem_a20_key directly for that. */
diff --git a/src/include/86box/86box.h b/src/include/86box/86box.h
index 83ca91ba8..1429c698c 100644
--- a/src/include/86box/86box.h
+++ b/src/include/86box/86box.h
@@ -120,6 +120,7 @@ extern int	enable_crashdump;		/* (C) enable crash dump */
 
 extern int	is_pentium;			/* TODO: Move back to cpu/cpu.h when it's figured out,
 							 how to remove that hack from the ET4000/W32p. */
+extern int	fixed_size_x, fixed_size_y;
 
 
 #ifdef ENABLE_LOG_TOGGLES
diff --git a/src/include/86box/resource.h b/src/include/86box/resource.h
index 28abd983b..3a029a25f 100644
--- a/src/include/86box/resource.h
+++ b/src/include/86box/resource.h
@@ -28,6 +28,7 @@
 #define DLG_STATUS		102	/* top-level dialog */
 #define DLG_SND_GAIN		103	/* top-level dialog */
 #define DLG_NEW_FLOPPY		104	/* top-level dialog */
+#define DLG_SPECIFY_DIM		105	/* top-level dialog */
 #define DLG_CONFIG		110	/* top-level dialog */
 #define  DLG_CFG_MACHINE	111	/* sub-dialog of config */
 #define  DLG_CFG_VIDEO		112	/* sub-dialog of config */
@@ -256,7 +257,6 @@
 #define IDC_COMBO_DISK_SIZE	1201
 #define IDC_COMBO_RPM_MODE	1202
 
-
 /* For the DeviceConfig code, re-do later. */
 #define IDC_CONFIG_BASE		1300
 #define  IDC_CONFIGURE_VID	1300
@@ -277,6 +277,11 @@
 #define IDC_RENDER		1381
 #define IDC_STATUS		1382
 
+#define IDC_EDIT_WIDTH		1400	/* specify main window dimensions dialog */
+#define IDC_WIDTHSPIN		1401
+#define IDC_EDIT_HEIGHT		1402
+#define IDC_HEIGHTSPIN		1403
+#define IDC_CHECK_LOCK_SIZE	1404
 
 #define IDM_ABOUT		40001
 #define IDC_ABOUT_ICON		65535
@@ -308,12 +313,13 @@
 #define IDM_VID_SCALE_2X	40056
 #define IDM_VID_SCALE_3X	40057
 #define IDM_VID_SCALE_4X	40058
-#define IDM_VID_HIDPI       40059
+#define IDM_VID_HIDPI		40059
 #define IDM_VID_FULLSCREEN	40060
 #define IDM_VID_FS_FULL		40061
 #define IDM_VID_FS_43		40062
 #define IDM_VID_FS_KEEPRATIO	40063
 #define IDM_VID_FS_INT		40064
+#define IDM_VID_SPECIFY_DIM	40065
 #define IDM_VID_FORCE43		40066
 #define IDM_VID_OVERSCAN	40067
 #define IDM_VID_INVERT		40069
diff --git a/src/include/86box/win.h b/src/include/86box/win.h
index 7c642cbc2..0f0162c11 100644
--- a/src/include/86box/win.h
+++ b/src/include/86box/win.h
@@ -174,6 +174,10 @@ extern void	SoundGainDialogCreate(HWND hwnd);
 extern void	NewFloppyDialogCreate(HWND hwnd, int id, int part);
 
 
+/* Functions in win_specify_dim.c: */
+extern void	SpecifyDimensionsDialogCreate(HWND hwnd);
+
+
 /* Functions in win_settings.c: */
 #define SETTINGS_PAGE_MACHINE			0
 #define SETTINGS_PAGE_VIDEO			1
diff --git a/src/machine/machine.c b/src/machine/machine.c
index e3869c970..045e81c30 100644
--- a/src/machine/machine.c
+++ b/src/machine/machine.c
@@ -81,7 +81,7 @@ machine_init_ex(int m)
 
 	/* Reset the memory state. */
 	mem_reset();
-	smbase = 0x00030000;
+	smbase = is_486_org ? 0x00060000 : 0x00030000;
 
 	lpt_init();
     }
diff --git a/src/machine/machine_table.c b/src/machine/machine_table.c
index 3b0667b6f..6cdc5af37 100644
--- a/src/machine/machine_table.c
+++ b/src/machine/machine_table.c
@@ -285,7 +285,7 @@ const machine_t machines[] = {
     { "[i430FX] PC Partner MB500N",		"mb500n",		MACHINE_TYPE_SOCKET5,		CPU_PKG_SOCKET5_7, 0, 50000000, 66666667, 3380, 3520, 1.5, 3.0,							MACHINE_PCI | MACHINE_IDE_DUAL,							 8192, 131072, 8192, 127,	       machine_at_mb500n_init, NULL			},
 
     /* OPTi 596/597 */
-    { "[OPTi 597] TMC PAT54PV",		"pat54pv",		MACHINE_TYPE_SOCKET5,		CPU_PKG_SOCKET5_7, CPU_BLOCK(CPU_K5, CPU_5K86), 60000000, 66666667, 3520, 3520, 1.5, 1.5,				MACHINE_VLB,									 2048,  65536, 2048, 127,	      machine_at_pat54pv_init, NULL			},
+    { "[OPTi 597] TMC PAT54PV",		"pat54pv",			MACHINE_TYPE_SOCKET5,		CPU_PKG_SOCKET5_7, CPU_BLOCK(CPU_K5, CPU_5K86), 50000000, 66666667, 3520, 3520, 1.5, 1.5,				MACHINE_VLB,									 2048,  65536, 2048, 127,	      machine_at_pat54pv_init, NULL			},
     
     /* OPTi 596/597/822 */
     { "[OPTi 597] Shuttle HOT-543",		"hot543",		MACHINE_TYPE_SOCKET5,		CPU_PKG_SOCKET5_7, 0, 60000000, 66666667, 3520, 3520, 1.5, 1.5,							MACHINE_PCI | MACHINE_VLB,				 8192, 131072, 8192, 127,		machine_at_hot543_init, NULL			},
diff --git a/src/win/86Box.rc b/src/win/86Box.rc
index 2fc62098e..da174a4fa 100644
--- a/src/win/86Box.rc
+++ b/src/win/86Box.rc
@@ -71,6 +71,7 @@ BEGIN
 #endif
         END
         MENUITEM SEPARATOR
+        MENUITEM "Specify dimensions",          IDM_VID_SPECIFY_DIM
         MENUITEM "F&orce 4:3 display ratio",    IDM_VID_FORCE43
         POPUP "&Window scale factor"
         BEGIN
@@ -342,6 +343,27 @@ BEGIN
 #endif
 END
 
+DLG_SPECIFY_DIM DIALOG DISCARDABLE  0, 0, 175, 66
+STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
+CAPTION "Specify Main Window Dimensions"
+FONT 9, "Segoe UI"
+BEGIN
+    LTEXT           "Width:",IDT_1709,7,9,24,12
+    EDITTEXT        IDC_EDIT_WIDTH,33,7,45,12,ES_AUTOHSCROLL | ES_NUMBER
+    CONTROL         "",IDC_WIDTHSPIN,"msctls_updown32",UDS_SETBUDDYINT | 
+                    UDS_ALIGNRIGHT | UDS_ARROWKEYS | UDS_NOTHOUSANDS,76,6,
+                    12,12
+    LTEXT           "Height:",IDT_1710,97,9,24,12
+    EDITTEXT        IDC_EDIT_HEIGHT,123,7,45,12,ES_AUTOHSCROLL | ES_NUMBER
+    CONTROL         "",IDC_HEIGHTSPIN,"msctls_updown32",UDS_SETBUDDYINT | 
+                    UDS_ALIGNRIGHT | UDS_ARROWKEYS | UDS_NOTHOUSANDS,166,6,
+                    12,12
+    CONTROL         "Lock to this size",IDC_CHECK_LOCK_SIZE,"Button",
+                    BS_AUTOCHECKBOX | WS_TABSTOP,7,26,94,10
+    DEFPUSHBUTTON   "OK",IDOK,30,45,50,14
+    PUSHBUTTON      "Cancel",IDCANCEL,99,45,50,14
+END
+
 DLG_CFG_MACHINE DIALOG DISCARDABLE  107, 0, 305, 200
 STYLE DS_CONTROL | WS_CHILD
 FONT 9, "Segoe UI"
diff --git a/src/win/CMakeLists.txt b/src/win/CMakeLists.txt
index 4f8a18268..07e9a8315 100644
--- a/src/win/CMakeLists.txt
+++ b/src/win/CMakeLists.txt
@@ -19,7 +19,7 @@ add_library(plat OBJECT win.c win_dynld.c win_thread.c win_cdrom.c
 	win_keyboard.c win_crashdump.c win_midi.c win_mouse.c)
 
 add_library(ui OBJECT win_ui.c win_stbar.c win_sdl.c win_dialog.c win_about.c
-	win_settings.c win_devconf.c win_snd_gain.c win_new_floppy.c
+	win_settings.c win_devconf.c win_snd_gain.c win_specify_dim.c win_new_floppy.c
 	win_jsconf.c win_media_menu.c 86Box.rc glad.c win_opengl.c)
 
 if(MSVC)
diff --git a/src/win/Makefile.mingw b/src/win/Makefile.mingw
index 1da78d3c6..7a0817b83 100644
--- a/src/win/Makefile.mingw
+++ b/src/win/Makefile.mingw
@@ -447,7 +447,7 @@ else
  UIOBJ		:= win_ui.o win_stbar.o \
 		   win_sdl.o win_opengl.o glad.o \
 		   win_dialog.o win_about.o \
-		   win_settings.o win_devconf.o win_snd_gain.o \
+		   win_settings.o win_devconf.o win_snd_gain.o win_specify_dim.o \
 		   win_new_floppy.o win_jsconf.o win_media_menu.o
 endif
 
diff --git a/src/win/win.c b/src/win/win.c
index c395c2ae1..d82d18c2a 100644
--- a/src/win/win.c
+++ b/src/win/win.c
@@ -1033,7 +1033,7 @@ plat_setfullscreen(int on)
 	plat_resize(scrnsz_x, scrnsz_y);
 	if (vid_resize) {
 		/* scale the screen base on DPI */
-		if (window_remember) {
+		if (!(vid_resize & 2) && window_remember) {
 			MoveWindow(hwndMain, window_x, window_y, window_w, window_h, TRUE);
 			GetClientRect(hwndMain, &rect);
 
@@ -1041,11 +1041,11 @@ plat_setfullscreen(int on)
 			temp_y = rect.bottom - rect.top + 1 - sbar_height;
 		} else {
 			if (dpi_scale) {
-				temp_x = MulDiv(unscaled_size_x, dpi, 96);
-				temp_y = MulDiv(unscaled_size_y, dpi, 96);
+				temp_x = MulDiv((vid_resize & 2) ? fixed_size_x : unscaled_size_x, dpi, 96);
+				temp_y = MulDiv((vid_resize & 2) ? fixed_size_y : unscaled_size_y, dpi, 96);
 			} else {
-				temp_x = unscaled_size_x;
-				temp_y = unscaled_size_y;
+				temp_x = (vid_resize & 2) ? fixed_size_x : unscaled_size_x;
+				temp_y = (vid_resize & 2) ? fixed_size_y : unscaled_size_y;
 			}
 
 			/* Main Window. */
@@ -1062,8 +1062,8 @@ plat_setfullscreen(int on)
 		if (mouse_capture)
 			ClipCursor(&rect);
 
-		scrnsz_x = unscaled_size_x;
-		scrnsz_y = unscaled_size_y;
+		scrnsz_x = (vid_resize & 2) ? fixed_size_x : unscaled_size_x;
+		scrnsz_y = (vid_resize & 2) ? fixed_size_y : unscaled_size_y;
 	}
     }
     video_fullscreen &= 1;
diff --git a/src/win/win_specify_dim.c b/src/win/win_specify_dim.c
new file mode 100644
index 000000000..547ee93b1
--- /dev/null
+++ b/src/win/win_specify_dim.c
@@ -0,0 +1,179 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		This file is part of the 86Box distribution.
+ *
+ *		Handle the dialog for specifying the dimensions of the main window.
+ *
+ *
+ *
+ * Authors:	Miran Grca, <mgrca8@gmail.com>
+ *
+ *		Copyright 2016-2018 Miran Grca.
+ */
+#define UNICODE
+#define BITMAP WINDOWS_BITMAP
+#include <windows.h>
+#include <windowsx.h>
+#undef BITMAP
+#include <commctrl.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include <86box/86box.h>
+#include <86box/config.h>
+#include <86box/plat.h>
+#include <86box/sound.h>
+#include <86box/win.h>
+
+
+#if defined(__amd64__) || defined(__aarch64__)
+static LRESULT CALLBACK
+#else
+static BOOL CALLBACK
+#endif
+SpecifyDimensionsDialogProcedure(HWND hdlg, UINT message, WPARAM wParam, LPARAM lParam)
+{
+    HWND h, h2;
+    HMENU hmenu;
+    UDACCEL accel, accel2;
+    RECT r;
+    uint32_t temp_x = 0, temp_y = 0;
+    int dpi = 96, lock;
+    LPTSTR lptsTemp;
+    char *stransi;
+
+    switch (message) {
+	case WM_INITDIALOG:
+		GetWindowRect(hwndRender, &r);
+
+		h = GetDlgItem(hdlg, IDC_WIDTHSPIN);
+		h2 = GetDlgItem(hdlg, IDC_EDIT_WIDTH);
+		SendMessage(h, UDM_SETBUDDY, (WPARAM)h2, 0);
+		SendMessage(h, UDM_SETRANGE, 0, (120 << 16) | 2048);
+		accel.nSec = 0;
+		accel.nInc = 8;
+		SendMessage(h, UDM_SETACCEL, 1, (LPARAM)&accel);
+		SendMessage(h, UDM_SETPOS, 0, r.right - r.left);
+
+		h = GetDlgItem(hdlg, IDC_HEIGHTSPIN);
+		h2 = GetDlgItem(hdlg, IDC_EDIT_HEIGHT);
+		SendMessage(h, UDM_SETBUDDY, (WPARAM)h2, 0);
+		SendMessage(h, UDM_SETRANGE, 0, (120 << 16) | 2048);
+		accel2.nSec = 0;
+		accel2.nInc = 8;
+		SendMessage(h, UDM_SETACCEL, 1, (LPARAM)&accel2);
+		SendMessage(h, UDM_SETPOS, 0, r.bottom - r.top);
+
+		h = GetDlgItem(hdlg, IDC_CHECK_LOCK_SIZE);
+		SendMessage(h, BM_SETCHECK, !!(vid_resize & 2), 0);
+		break;
+
+	case WM_COMMAND:
+                switch (LOWORD(wParam)) {
+			case IDOK:
+				lptsTemp = (LPTSTR) malloc(512 * sizeof(WCHAR));
+				stransi = (char *)malloc(512);
+
+				h = GetDlgItem(hdlg, IDC_EDIT_WIDTH);
+				SendMessage(h, WM_GETTEXT, 255, (LPARAM) lptsTemp);
+				wcstombs(stransi, lptsTemp, 512);
+				sscanf(stransi, "%u", &temp_x);
+				fixed_size_x = temp_x;
+
+				h = GetDlgItem(hdlg, IDC_EDIT_HEIGHT);
+				SendMessage(h, WM_GETTEXT, 255, (LPARAM) lptsTemp);
+				wcstombs(stransi, lptsTemp, 512);
+				sscanf(stransi, "%u", &temp_y);
+				fixed_size_y = temp_y;
+
+				h = GetDlgItem(hdlg, IDC_CHECK_LOCK_SIZE);
+				lock = SendMessage(h, BM_GETCHECK, 0, 0);
+
+				if (lock) {
+					vid_resize = 2;
+					window_remember = 0;
+				} else {
+					vid_resize = 1;
+					window_remember = 1;
+				}
+				hmenu = GetMenu(hwndMain);
+				CheckMenuItem(hmenu, IDM_VID_REMEMBER, (window_remember == 1) ? MF_CHECKED : MF_UNCHECKED);
+				CheckMenuItem(hmenu, IDM_VID_RESIZE, (vid_resize == 1) ? MF_CHECKED : MF_UNCHECKED);
+				EnableMenuItem(hmenu, IDM_VID_RESIZE, (vid_resize & 2) ? MF_GRAYED : MF_ENABLED);
+
+				if (vid_resize == 1)
+					SetWindowLongPtr(hwndMain, GWL_STYLE, (WS_OVERLAPPEDWINDOW) | WS_VISIBLE);
+				else
+					SetWindowLongPtr(hwndMain, GWL_STYLE, (WS_OVERLAPPEDWINDOW & ~WS_SIZEBOX & ~WS_MAXIMIZEBOX) | WS_VISIBLE);
+
+				/* scale the screen base on DPI */
+				if (dpi_scale) {
+					dpi = win_get_dpi(hwndMain);
+					temp_x = MulDiv(temp_x, dpi, 96);
+					temp_y = MulDiv(temp_y, dpi, 96);
+				} else {
+					temp_x = temp_x;
+					temp_y = temp_y;
+				}
+
+				ResizeWindowByClientArea(hwndMain, temp_x, temp_y + sbar_height);
+
+				if (vid_resize) {
+					CheckMenuItem(hmenu, IDM_VID_SCALE_1X + scale, MF_UNCHECKED);
+					CheckMenuItem(hmenu, IDM_VID_SCALE_2X, MF_CHECKED);
+					scale = 1;
+				}
+				EnableMenuItem(hmenu, IDM_VID_SCALE_1X, vid_resize ? MF_GRAYED : MF_ENABLED);
+				EnableMenuItem(hmenu, IDM_VID_SCALE_2X, vid_resize ? MF_GRAYED : MF_ENABLED);
+				EnableMenuItem(hmenu, IDM_VID_SCALE_3X, vid_resize ? MF_GRAYED : MF_ENABLED);
+				EnableMenuItem(hmenu, IDM_VID_SCALE_4X, vid_resize ? MF_GRAYED : MF_ENABLED);
+
+				scrnsz_x = fixed_size_x;
+				scrnsz_y = fixed_size_y;
+				doresize = 1;
+
+				GetWindowRect(hwndMain, &r);
+
+				if (mouse_capture)
+					ClipCursor(&r);
+
+				if (!(vid_resize & 2) && window_remember) {
+					window_x = r.left;
+					window_y = r.top;
+					window_w = r.right - r.left;
+					window_h = r.bottom - r.top;
+				}
+
+				config_save();
+
+				free(stransi);
+				free(lptsTemp);
+
+				EndDialog(hdlg, 0);
+				return TRUE;
+
+			case IDCANCEL:
+				EndDialog(hdlg, 0);
+				return TRUE;
+
+			default:
+				break;
+		}
+		break;
+    }
+
+    return(FALSE);
+}
+
+
+void
+SpecifyDimensionsDialogCreate(HWND hwnd)
+{
+    DialogBox(hinstance, (LPCTSTR)DLG_SPECIFY_DIM, hwnd, SpecifyDimensionsDialogProcedure);
+}
diff --git a/src/win/win_ui.c b/src/win/win_ui.c
index de0dba0d8..de76d142b 100644
--- a/src/win/win_ui.c
+++ b/src/win/win_ui.c
@@ -61,11 +61,12 @@ HWND		hwndMain,		/* application main window */
 HMENU		menuMain;		/* application main menu */
 HICON		hIcon[256];		/* icon data loaded from resources */
 RECT		oldclip;		/* mouse rect */
-int		sbar_height = 23;     /* statusbar height */
+int		sbar_height = 23;	/* statusbar height */
 int		minimized = 0;
-int		infocus = 1;
+int		infocus = 1, button_down = 0;
 int		rctrl_is_lalt = 0;
 int		user_resize = 0;
+int		fixed_size_x = 0, fixed_size_y = 0;
 
 extern char	openfilestring[512];
 extern WCHAR	wopenfilestring[512];
@@ -125,7 +126,7 @@ int win_get_system_metrics(int index, int dpi) {
 void
 ResizeWindowByClientArea(HWND hwnd, int width, int height)
 {
-	if (vid_resize || padded_frame) {
+	if ((vid_resize == 1) || padded_frame) {
 		int padding = win_get_system_metrics(SM_CXPADDEDBORDER, dpi);
 		width  += (win_get_system_metrics(SM_CXFRAME, dpi) + padding) * 2;
 		height += (win_get_system_metrics(SM_CYFRAME, dpi) + padding) * 2;
@@ -279,13 +280,13 @@ ResetAllMenus(void)
     CheckMenuItem(menuMain, IDM_VID_OVERSCAN, enable_overscan?MF_CHECKED:MF_UNCHECKED);
     CheckMenuItem(menuMain, IDM_VID_INVERT, invert_display ? MF_CHECKED : MF_UNCHECKED);
 
-    if (vid_resize)
+    if (vid_resize == 1)
 	CheckMenuItem(menuMain, IDM_VID_RESIZE, MF_CHECKED);
     CheckMenuItem(menuMain, IDM_VID_SDL_SW+vid_api, MF_CHECKED);
     CheckMenuItem(menuMain, IDM_VID_FS_FULL+video_fullscreen_scale, MF_CHECKED);
     CheckMenuItem(menuMain, IDM_VID_REMEMBER, window_remember?MF_CHECKED:MF_UNCHECKED);
     CheckMenuItem(menuMain, IDM_VID_SCALE_1X+scale, MF_CHECKED);
-	CheckMenuItem(menuMain, IDM_VID_HIDPI, dpi_scale?MF_CHECKED:MF_UNCHECKED);
+    CheckMenuItem(menuMain, IDM_VID_HIDPI, dpi_scale?MF_CHECKED:MF_UNCHECKED);
 
     CheckMenuItem(menuMain, IDM_VID_CGACON, vid_cga_contrast?MF_CHECKED:MF_UNCHECKED);
     CheckMenuItem(menuMain, IDM_VID_GRAYCT_601+video_graytype, MF_CHECKED);
@@ -300,6 +301,20 @@ ResetAllMenus(void)
 #ifdef MTR_ENABLED
     EnableMenuItem(menuMain, IDM_ACTION_END_TRACE, MF_DISABLED);
 #endif
+
+    if (vid_resize) {
+	if (vid_resize >= 2) {
+		CheckMenuItem(menuMain, IDM_VID_RESIZE, MF_UNCHECKED);
+		EnableMenuItem(menuMain, IDM_VID_RESIZE, MF_GRAYED);
+	}
+
+	CheckMenuItem(menuMain, IDM_VID_SCALE_1X + scale, MF_UNCHECKED);
+	CheckMenuItem(menuMain, IDM_VID_SCALE_2X, MF_CHECKED);
+	EnableMenuItem(menuMain, IDM_VID_SCALE_1X, MF_GRAYED);
+	EnableMenuItem(menuMain, IDM_VID_SCALE_2X, MF_GRAYED);
+	EnableMenuItem(menuMain, IDM_VID_SCALE_3X, MF_GRAYED);
+	EnableMenuItem(menuMain, IDM_VID_SCALE_4X, MF_GRAYED);
+    }
 }
 
 
@@ -456,10 +471,14 @@ input_proc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 #endif
 		break;
 
+	case WM_LBUTTONDOWN:
+		button_down |= 1;
+		break;
+
 	case WM_LBUTTONUP:
-		pclog("video_fullscreen = %i\n", video_fullscreen);
-		if (! video_fullscreen)
+		if ((button_down & 1) && !video_fullscreen)
 			plat_mouse_capture(1);
+		button_down &= ~1;
 		break;
 
 	case WM_MBUTTONUP:
@@ -511,12 +530,12 @@ MainWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 				break;
 
 #ifdef MTR_ENABLED
-            case IDM_ACTION_BEGIN_TRACE:
-            case IDM_ACTION_END_TRACE:
-            case IDM_ACTION_TRACE:
-                tracing_on = !tracing_on;
-                handle_trace(hmenu, tracing_on);
-                break;
+		case IDM_ACTION_BEGIN_TRACE:
+		case IDM_ACTION_END_TRACE:
+		case IDM_ACTION_TRACE:
+			tracing_on = !tracing_on;
+			handle_trace(hmenu, tracing_on);
+			break;
 #endif
 
 			case IDM_ACTION_HRESET:
@@ -595,10 +614,10 @@ MainWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 				break;
 
 			case IDM_VID_RESIZE:
-				vid_resize = !vid_resize;
-				CheckMenuItem(hmenu, IDM_VID_RESIZE, (vid_resize)? MF_CHECKED : MF_UNCHECKED);
+				vid_resize ^= 1;
+				CheckMenuItem(hmenu, IDM_VID_RESIZE, (vid_resize & 1) ? MF_CHECKED : MF_UNCHECKED);
 
-				if (vid_resize)
+				if (vid_resize == 1)
 					SetWindowLongPtr(hwnd, GWL_STYLE, (WS_OVERLAPPEDWINDOW) | WS_VISIBLE);
 				else
 					SetWindowLongPtr(hwnd, GWL_STYLE, (WS_OVERLAPPEDWINDOW & ~WS_SIZEBOX & ~WS_MAXIMIZEBOX) | WS_VISIBLE);
@@ -638,7 +657,7 @@ MainWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 				window_remember = !window_remember;
 				CheckMenuItem(hmenu, IDM_VID_REMEMBER, window_remember ? MF_CHECKED : MF_UNCHECKED);
 				GetWindowRect(hwnd, &rect);
-				if (window_remember) {
+				if (!(vid_resize & 2) && window_remember) {
 					window_x = rect.left;
 					window_y = rect.top;
 					window_w = rect.right - rect.left;
@@ -696,6 +715,10 @@ MainWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 				config_save();
 				break;
 
+			case IDM_VID_SPECIFY_DIM:
+				SpecifyDimensionsDialogCreate(hwnd);
+				break;
+
 			case IDM_VID_FORCE43:
 				video_toggle_option(hmenu, &force_43, IDM_VID_FORCE43);
 				video_force_resize_set(1);
@@ -829,9 +852,19 @@ MainWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 		GetWindowRect(hwndSBAR, &rect);
 		sbar_height = rect.bottom - rect.top;
 		rect_p = (RECT*)lParam;
-		if (vid_resize)
+		if (vid_resize == 1)
 			MoveWindow(hwnd, rect_p->left, rect_p->top, rect_p->right - rect_p->left, rect_p->bottom - rect_p->top, TRUE);
-		else if (!user_resize)
+		else if (vid_resize >= 2) {
+			temp_x = fixed_size_x;
+			temp_y = fixed_size_y;
+			if (dpi_scale) {
+				temp_x = MulDiv(temp_x, dpi, 96);
+				temp_y = MulDiv(temp_y, dpi, 96);
+			}
+
+			/* Main Window. */
+			ResizeWindowByClientArea(hwndMain, temp_x, temp_y + sbar_height);
+		} else if (!user_resize)
 			doresize = 1;
 		break;
 
@@ -1063,9 +1096,14 @@ static LRESULT CALLBACK
 SubWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
     switch (message) {
+	case WM_LBUTTONDOWN:
+		button_down |= 2;
+		break;
+
 	case WM_LBUTTONUP:
-		if (! video_fullscreen)
+		if ((button_down & 2) && !video_fullscreen)
 			plat_mouse_capture(1);
+		button_down &= ~2;
 		break;
 
 	case WM_MBUTTONUP:
@@ -1230,10 +1268,10 @@ ui_init(int nCmdShow)
     sbar_height = sbar_rect.bottom - sbar_rect.top;
 
     /* Set up main window for resizing if configured. */
-    if (vid_resize)
+    if (vid_resize == 1)
 	SetWindowLongPtr(hwnd, GWL_STYLE,
 			(WS_OVERLAPPEDWINDOW));
-      else
+    else
 	SetWindowLongPtr(hwnd, GWL_STYLE,
 			(WS_OVERLAPPEDWINDOW&~WS_SIZEBOX&~WS_THICKFRAME&~WS_MAXIMIZEBOX));
 
@@ -1243,10 +1281,15 @@ ui_init(int nCmdShow)
 
     /* Initiate a resize in order to properly arrange all controls.
        Move to the last-saved position if needed. */
-    if (window_remember)
+    if ((vid_resize < 2) && window_remember)
 	MoveWindow(hwnd, window_x, window_y, window_w, window_h, TRUE);
-    else
+    else {
+	if (vid_resize >= 2) {
+		scrnsz_x = fixed_size_x;
+		scrnsz_y = fixed_size_y;
+	}
 	ResizeWindowByClientArea(hwndMain, scrnsz_x, scrnsz_y + sbar_height);
+    }
 
     /* Reset all menus to their defaults. */
     ResetAllMenus();
@@ -1466,7 +1509,6 @@ plat_resize(int x, int y)
 {
     /* First, see if we should resize the UI window. */
     if (!vid_resize) {
-
 	/* scale the screen base on DPI */
 	if (dpi_scale) {
 		x = MulDiv(x, dpi, 96);