add machine Multitech PC-500 with BIOS ROM v3.10 and v3.30

src/machine/machine_table.c

@@ -1094,6 +1094,49 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
+    {
+        .name = "[8088] Multitech PC-500",
+        .internal_name = "pc500",
+        .type = MACHINE_TYPE_8088,
+        .chipset = MACHINE_CHIPSET_DISCRETE,
+        .init = machine_xt_pc500_init,
+        .p1_handler = NULL,
+        .gpio_handler = NULL,
+        .available_flag = MACHINE_AVAILABLE,
+        .gpio_acpi_handler = NULL,
+        .cpu = {
+            .package = CPU_PKG_8088,
+            .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_PC,
+        .flags = MACHINE_FLAGS_NONE,
+        .ram = {
+            .min = 128,
+            .max = 640,
+            .step = 64
+        },
+        .nvrmask = 0,
+        .jumpered_ecp_dma = 0,
+        .default_jumpered_ecp_dma = -1,
+        .kbc_device = &kbc_pc_device,
+        .kbc_params = 0x00000000,
+        .kbc_p1 = 0xff,
+        .gpio = 0xffffffff,
+        .gpio_acpi = 0xffffffff,
+        .device = &pc500_device,
+        .kbd_device = &keyboard_pc_xt_device,
+        .fdc_device = NULL,
+        .sio_device = NULL,
+        .vid_device = NULL,
+        .snd_device = NULL,
+        .net_device = NULL
+    },
     {
         .name = "[8088] Multitech PC-500 plus",
         .internal_name = "pc500plus",