diff --git a/src/machine/m_tandy.c b/src/machine/m_tandy.c
index 5784eb4df..6cd1afde9 100644
--- a/src/machine/m_tandy.c
+++ b/src/machine/m_tandy.c
@@ -128,6 +128,7 @@ typedef struct tandy_t {
     int      rom_offset; /* SL2 */
 
     uint32_t base;
+    uint32_t mask;
     int      is_sl2;
 
     t1kvid_t *vid;
@@ -1319,8 +1320,19 @@ tandy_write(uint16_t addr, uint8_t val, void *priv)
 
     switch (addr) {
         case 0x00a0:
-            mem_mapping_set_addr(&dev->ram_mapping,
-                                 ((val >> 1) & 7) * 128 * 1024, 0x20000);
+            if (val & 0x10) {
+                dev->base = (mem_size - 256) * 1024;
+                dev->mask = 0x3ffff;
+                mem_mapping_set_addr(&ram_low_mapping, 0, dev->base);
+                mem_mapping_set_addr(&dev->ram_mapping,
+                                     ((val >> 1) & 7) * 128 * 1024, 0x40000);
+            } else {
+                dev->base = (mem_size - 128) * 1024;
+                dev->mask = 0x1ffff;
+                mem_mapping_set_addr(&ram_low_mapping, 0, dev->base);
+                mem_mapping_set_addr(&dev->ram_mapping,
+                                     ((val >> 1) & 7) * 128 * 1024, 0x20000);
+            }
             dev->ram_bank = val;
             break;
 
@@ -1378,7 +1390,7 @@ write_ram(uint32_t addr, uint8_t val, void *priv)
 {
     const tandy_t *dev = (tandy_t *) priv;
 
-    ram[dev->base + (addr & 0x1ffff)] = val;
+    ram[dev->base + (addr & dev->mask)] = val;
 }
 
 static uint8_t
@@ -1386,7 +1398,7 @@ read_ram(uint32_t addr, void *priv)
 {
     const tandy_t *dev = (tandy_t *) priv;
 
-    return (ram[dev->base + (addr & 0x1ffff)]);
+    return (ram[dev->base + (addr & dev->mask)]);
 }
 
 static uint8_t
@@ -1462,8 +1474,10 @@ machine_tandy1k_init(const machine_t *model, int type)
      * 0xFFE8 (SL2), so we remove it from the main mapping.
      */
     dev->base = (mem_size - 128) * 1024;
-    mem_mapping_add(&dev->ram_mapping, 0x80000, 0x20000,
-                    read_ram, NULL, NULL, write_ram, NULL, NULL, NULL, 0, dev);
+    dev->mask = 0x1ffff;
+    mem_mapping_add(&dev->ram_mapping, 0x60000, 0x20000,
+                    read_ram, NULL, NULL, write_ram, NULL, NULL, NULL,
+                    MEM_MAPPING_INTERNAL, dev);
     mem_mapping_set_addr(&ram_low_mapping, 0, dev->base);
 
     device_add(&keyboard_tandy_device);
diff --git a/src/machine/m_xt.c b/src/machine/m_xt.c
index 84eb517c8..fe519c65b 100644
--- a/src/machine/m_xt.c
+++ b/src/machine/m_xt.c
@@ -310,7 +310,9 @@ machine_xt_pxxt_init(const machine_t *model)
     if (bios_only || !ret)
         return ret;
 
-    machine_xt_clone_init(model);
+    device_add(&keyboard_xt_device);
+
+    machine_xt_common_init(model);
 
     return ret;
 }