diff --git a/src/machine/m_at_386dx_486.c b/src/machine/m_at_386dx_486.c
index 41fa3c946..d4cd5fe16 100644
--- a/src/machine/m_at_386dx_486.c
+++ b/src/machine/m_at_386dx_486.c
@@ -687,7 +687,7 @@ machine_at_pb450_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear("roms/machines/pb450/OPTI802.BIN",
+    ret = bios_load_linear("roms/machines/pb450/OPTI802.bin",
                            0x000e0000, 131072, 0);
 
     if (bios_only || !ret)
@@ -1367,7 +1367,7 @@ machine_at_amis76_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear_inverted("roms/machines/s76p/s76p.rom", 
+    ret = bios_load_linear_inverted("roms/machines/s76p/S76P.ROM", 
                                     0x000e0000, 131072, 0);
 
     if (bios_only || !ret)
diff --git a/src/machine/m_at_socket5.c b/src/machine/m_at_socket5.c
index 773f8d980..ff59ec65f 100644
--- a/src/machine/m_at_socket5.c
+++ b/src/machine/m_at_socket5.c
@@ -64,8 +64,8 @@ machine_at_dellplato_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear_combined("roms/machines/dellplato/1016AX1J.bio",
-                                    "roms/machines/dellplato/1016AX1J.bi1",
+    ret = bios_load_linear_combined("roms/machines/dellplato/1016AX1J.BIO",
+                                    "roms/machines/dellplato/1016AX1J.BI1",
                                     0x1d000, 128);
 
     if (bios_only || !ret)
diff --git a/src/machine/m_xt.c b/src/machine/m_xt.c
index 9a0b39a89..ded68f5dc 100644
--- a/src/machine/m_xt.c
+++ b/src/machine/m_xt.c
@@ -339,7 +339,7 @@ machine_xt_pravetz16_imko4_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear("roms/machines/pravetz16/BIOS_IMKO4_FE00.BIN",
+    ret = bios_load_linear("roms/machines/pravetz16/BIOS_IMKO4_FE00.bin",
                            0x000fe000, 65536, 0);
     if (ret) {
         bios_load_aux_linear("roms/machines/pravetz16/BIOS_IMKO4_F400.BIN",