diff --git a/src/chipset/sis_85c496.c b/src/chipset/sis_85c496.c
index 4d1db2d9e..b9b2544c8 100644
--- a/src/chipset/sis_85c496.c
+++ b/src/chipset/sis_85c496.c
@@ -123,7 +123,7 @@ sis_85c497_isa_read(uint16_t port, void *priv)
     const sis_85c496_t *dev = (sis_85c496_t *) priv;
     uint8_t             ret = 0xff;
 
-    if (port == 0x23)
+    if ((port == 0x23) && (dev->cur_reg < 0xc0))
         ret = dev->regs[dev->cur_reg];
     else if (port == 0x33)
         ret = 0x3c /*random_generate()*/;
diff --git a/src/machine/machine_table.c b/src/machine/machine_table.c
index d2e49709e..13a5d5452 100644
--- a/src/machine/machine_table.c
+++ b/src/machine/machine_table.c
@@ -7793,7 +7793,7 @@ const machine_t machines[] = {
         .gpio_acpi_handler = NULL,
         .cpu = {
             .package = CPU_PKG_SOCKET3,
-            .block = CPU_BLOCK(CPU_i486SX, CPU_i486DX, CPU_Am486SX, CPU_Am486DX, CPU_Cx486S, CPU_Cx486DX, CPU_Cx5x86),
+            .block = CPU_BLOCK(CPU_i486SX, CPU_i486DX, CPU_Am486SX, CPU_Am486DX),
             .min_bus = 0,
             .max_bus = 0,
             .min_voltage = 0,