diff --git a/src/include/86box/machine.h b/src/include/86box/machine.h
index f1a76487a..9741f2bcd 100644
--- a/src/include/86box/machine.h
+++ b/src/include/86box/machine.h
@@ -304,9 +304,7 @@ extern int	machine_at_pb680_init(const machine_t *);
 extern int	machine_at_nupro592_init(const machine_t *);
 extern int	machine_at_tx97_init(const machine_t *);
 extern int	machine_at_ym430tx_init(const machine_t *);
-#if defined(DEV_BRANCH) && defined(NO_SIO)
-extern int	machine_at_586t2_init(const machine_t *);
-#endif
+extern int	machine_at_mb540n_init(const machine_t *);
 extern int	machine_at_p5mms98_init(const machine_t *);
 
 extern int	machine_at_ficva502_init(const machine_t *);
diff --git a/src/machine/m_at_socket7_s7.c b/src/machine/m_at_socket7_s7.c
index e41a39013..a53216e1f 100644
--- a/src/machine/m_at_socket7_s7.c
+++ b/src/machine/m_at_socket7_s7.c
@@ -816,13 +816,12 @@ machine_at_ym430tx_init(const machine_t *model)
     return ret;
 }
 
-#if defined(DEV_BRANCH) && defined(NO_SIO)
 int
-machine_at_586t2_init(const machine_t *model)
+machine_at_mb540n_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear(L"roms/machines/586t2/5itw001.bin",
+    ret = bios_load_linear(L"roms/machines/mb540n/Tx0720ug.bin",
 			   0x000e0000, 131072, 0);
 
     if (bios_only || !ret)
@@ -832,21 +831,20 @@ machine_at_586t2_init(const machine_t *model)
 
     pci_init(PCI_CONFIG_TYPE_1);
     pci_register_slot(0x00, PCI_CARD_NORTHBRIDGE, 0, 0, 0, 0);
-    pci_register_slot(0x09, PCI_CARD_NORMAL, 1, 2, 3, 4);
-    pci_register_slot(0x0A, PCI_CARD_NORMAL, 2, 3, 4, 1);
-    pci_register_slot(0x0B, PCI_CARD_NORMAL, 3, 4, 1, 2);
-    pci_register_slot(0x0C, PCI_CARD_NORMAL, 4, 1, 2, 3);
+    pci_register_slot(0x11, PCI_CARD_NORMAL, 4, 1, 2, 3);
+    pci_register_slot(0x12, PCI_CARD_NORMAL, 3, 4, 1, 2);
+    pci_register_slot(0x13, PCI_CARD_NORMAL, 2, 3, 4, 1);
+    pci_register_slot(0x14, PCI_CARD_NORMAL, 1, 2, 3, 4);
     pci_register_slot(0x07, PCI_CARD_SOUTHBRIDGE, 1, 2, 3, 4);	/* PIIX4 */
     device_add(&i430tx_device);
     device_add(&piix4_device);
     device_add(&keyboard_ps2_pci_device);
-    device_add(&um8669f_device); /*Placeholder for ITE 8679*/
+    device_add(&um8669f_device);
     device_add(&sst_flash_29ee010_device);
     spd_register(SPD_TYPE_SDRAM, 0x3, 128);
 
     return ret;
 }
-#endif
 
 int
 machine_at_p5mms98_init(const machine_t *model)
diff --git a/src/machine/machine_table.c b/src/machine/machine_table.c
index b345d052b..339e07dff 100644
--- a/src/machine/machine_table.c
+++ b/src/machine/machine_table.c
@@ -260,10 +260,8 @@ const machine_t machines[] = {
     /* 430TX */
     { "[Socket 7 TX] ADLink NuPRO-592",		"nupro592",		MACHINE_CPUS_PENTIUM_S7,											    MACHINE_PCI | MACHINE_ISA | MACHINE_AT | MACHINE_PS2 | MACHINE_HDC,					  8,  256,   8, 255,	     machine_at_nupro592_init, NULL			},
     { "[Socket 7 TX] ASUS TX97",		"tx97",			MACHINE_CPUS_PENTIUM_S7,											    MACHINE_PCI | MACHINE_ISA | MACHINE_AT | MACHINE_PS2 | MACHINE_HDC,					  8,  256,   8, 255,	         machine_at_tx97_init, NULL			},
-#if defined(DEV_BRANCH) && defined(NO_SIO)
-    { "[Socket 7 TX] Gigabyte GA-586T2",        "586t2",		MACHINE_CPUS_PENTIUM_S7,											    MACHINE_PCI | MACHINE_ISA | MACHINE_AT | MACHINE_PS2 | MACHINE_HDC,					  8,  256,   8, 255,	        machine_at_586t2_init, NULL			},
-#endif
     { "[Socket 7 TX] Intel YM430TX",		"ym430tx",		MACHINE_CPUS_PENTIUM_S7,											    MACHINE_PCI | MACHINE_ISA | MACHINE_AT | MACHINE_PS2 | MACHINE_HDC,					  8,  256,   8, 255,	      machine_at_ym430tx_init, NULL			},
+    { "[Socket 7 TX] PC Partner MB540N",        "mb540n",		MACHINE_CPUS_PENTIUM_S7,											    MACHINE_PCI | MACHINE_ISA | MACHINE_AT | MACHINE_PS2 | MACHINE_HDC,					  8,  256,   8, 255,	       machine_at_mb540n_init, NULL			},
     { "[Socket 7 TX] Supermicro P5MMS98",	"p5mms98",		MACHINE_CPUS_PENTIUM_S7,											    MACHINE_PCI | MACHINE_ISA | MACHINE_AT | MACHINE_PS2 | MACHINE_HDC,					  8,  256,   8, 255,	      machine_at_p5mms98_init, NULL			},