diff --git a/src/emucore/Cart4KSC.cxx b/src/emucore/Cart4KSC.cxx
index bf7c2c1bd..969472fa9 100644
--- a/src/emucore/Cart4KSC.cxx
+++ b/src/emucore/Cart4KSC.cxx
@@ -83,7 +83,7 @@ uInt8 Cartridge4KSC::peek(uInt16 address)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool Cartridge4KSC::poke(uInt16 address, uInt8 value)
 {
-  if(address & 0x080)
+  if (!(address & 0x080))
   {
     pokeRAM(myRAM[address & 0x007F], address, value);
     return true;
diff --git a/src/emucore/CartBFSC.cxx b/src/emucore/CartBFSC.cxx
index d41c290ce..63a5a840a 100644
--- a/src/emucore/CartBFSC.cxx
+++ b/src/emucore/CartBFSC.cxx
@@ -98,7 +98,7 @@ bool CartridgeBFSC::poke(uInt16 address, uInt8 value)
     return false;
   }
 
-  if(address & 0x080)
+  if (!(address & 0x080))
   {
     pokeRAM(myRAM[address & 0x007F], pokeAddress, value);
     return true;
diff --git a/src/emucore/CartEFSC.cxx b/src/emucore/CartEFSC.cxx
index 0a5069489..b30e111f5 100644
--- a/src/emucore/CartEFSC.cxx
+++ b/src/emucore/CartEFSC.cxx
@@ -98,7 +98,7 @@ bool CartridgeEFSC::poke(uInt16 address, uInt8 value)
     return false;
   }
 
-  if(address & 0x080)
+  if (!(address & 0x080))
   {
     pokeRAM(myRAM[address & 0x007F], pokeAddress, value);
     return true;
diff --git a/src/emucore/CartF4SC.cxx b/src/emucore/CartF4SC.cxx
index 9d468d28c..0daeb4fb3 100644
--- a/src/emucore/CartF4SC.cxx
+++ b/src/emucore/CartF4SC.cxx
@@ -98,7 +98,7 @@ bool CartridgeF4SC::poke(uInt16 address, uInt8 value)
     return false;
   }
 
-  if(address & 0x080)
+  if(!(address & 0x080))
   {
     pokeRAM(myRAM[address & 0x007F], pokeAddress, value);
     return true;
diff --git a/src/emucore/CartF6SC.cxx b/src/emucore/CartF6SC.cxx
index b9f47ae89..c03b1d4a0 100644
--- a/src/emucore/CartF6SC.cxx
+++ b/src/emucore/CartF6SC.cxx
@@ -138,7 +138,7 @@ bool CartridgeF6SC::poke(uInt16 address, uInt8 value)
       break;
   }
 
-  if(address & 0x080)
+  if(!(address & 0x080))
   {
     pokeRAM(myRAM[address & 0x007F], address, value);
     return true;
diff --git a/src/emucore/CartF8SC.cxx b/src/emucore/CartF8SC.cxx
index 5c4c8a523..2a7f9d8de 100644
--- a/src/emucore/CartF8SC.cxx
+++ b/src/emucore/CartF8SC.cxx
@@ -118,7 +118,7 @@ bool CartridgeF8SC::poke(uInt16 address, uInt8 value)
       break;
   }
 
-  if(address & 0x080)
+  if (!(address & 0x080))
   {
     pokeRAM(myRAM[address & 0x007F], address, value);
     return true;