3E and 3F bankswitching now pass pokes to addresses $00-$3F through to

the TIA. For 3E, this means game authors don't need to access the TIA
through a mirror (and there's no reason they should on real hardware,
either). It also means Armin's test cart image works.

3F ROMs still need to use a mirror: poking to $00-$2C writes to the
TIA *and* switches banks, which is not that you'd want to do. Stella's
behaviour now matches a real Tigervision 3F cart, for what it's worth.

Unfortunately I had to do something nasty to allow the Cart classes to
directly access the TIA: see System.hxx and System.cxx (search for
the tiaPoke() method.)


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@627 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

stella/src/emucore/Cart3E.cxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Cart3E.cxx,v 1.3 2005-07-08 12:16:01 urchlay Exp $
+// $Id: Cart3E.cxx,v 1.4 2005-07-09 00:59:12 urchlay Exp $
 //============================================================================
 
 #include <assert.h>
@@ -122,7 +122,8 @@ void Cartridge3E::poke(uInt16 address, uInt8 value)
 {
   address = address & 0x0FFF;
 
-  // Switch banks if necessary
+  // Switch banks if necessary. Armin (Kroko) says there are no mirrored
+  // hotspots.
   if(address == 0x003F)
   {
     bank(value);
@@ -132,8 +133,12 @@ void Cartridge3E::poke(uInt16 address, uInt8 value)
     bank(value + 256);
   }
 
-  // TODO: Ask Kroko whether addresses 0-0x3d do anything (on 3F, they
+  // Dirty hack alert!
-  // cause a bankswitch)
+  // Pass the poke through to the TIA. In a real Atari, both the cart and the
+  // TIA see the address lines, and both react accordingly. In Stella, each
+  // 64-byte chunk of address space is "owned" by only one device. If we
+  // don't chain the poke to the TIA, then the TIA can't see it...
+  mySystem->tiaPoke(address, value);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

stella/src/emucore/Cart3F.cxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Cart3F.cxx,v 1.7 2005-06-27 23:40:35 urchlay Exp $
+// $Id: Cart3F.cxx,v 1.8 2005-07-09 00:59:12 urchlay Exp $
 //============================================================================
 
 #include <assert.h>
@@ -67,8 +67,9 @@ void Cartridge3F::install(System& system)
   assert((0x1800 & mask) == 0);
 
   // Set the page accessing methods for the hot spots (for 100% emulation
-  // I would need to chain any accesses below 0x40 to the TIA but for
+  // we need to chain any accesses below 0x40 to the TIA. Our poke() method
-  // now I'll just forget about them)
+  // does this via mySystem->tiaPoke(...), at least until we come up with a
+  // cleaner way to do it.)
   System::PageAccess access;
   for(uInt32 i = 0x00; i < 0x40; i += (1 << shift))
   {
@@ -116,6 +117,10 @@ void Cartridge3F::poke(uInt16 address, uInt8 value)
   {
     bank(value);
   }
+
+  // pass pokes through to the TIA. This uses a DIRTY HACK which will
+  // (probably) go away in the future. See System.cxx for details.
+  mySystem->tiaPoke(address, value);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

stella/src/emucore/m6502/src/System.cxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: System.cxx,v 1.10 2005-06-21 05:00:46 urchlay Exp $
+// $Id: System.cxx,v 1.11 2005-07-09 00:59:13 urchlay Exp $
 //============================================================================
 
 #include <assert.h>
@@ -21,6 +21,7 @@
 
 #include "Device.hxx"
 #include "M6502.hxx"
+#include "TIA.hxx" // FIXME: this is a hack
 #include "System.hxx"
 #include "Serializer.hxx"
 #include "Deserializer.hxx"
@@ -349,3 +350,23 @@ void System::poke(uInt16 addr, uInt8 value)
 
   myDataBusState = value;
 }
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// FIXME: dirty hack! This only exists for Cart3E and Cart3F to use, and
+// then only until I come up a cleaner way to implement it. Call this method
+// at your own peril!
+
+// Note that in some compilers (VC++?) you need to enable RTTI to make the
+// dynamic_cast work. In g++, RTTI seems to be on by default. Do not
+// compile Stella with -fno-rtti!
+
+// Sorry about the mess.   -- B.
+void System::tiaPoke(uInt16 addr, uInt8 value)
+{
+  TIA *t;
+  for(uInt32 i = 0; i < myNumberOfDevices; ++i)
+  {
+    if( (t = dynamic_cast<TIA*>(myDevices[i])) )
+      t->poke(addr, value);
+  }
+}

stella/src/emucore/m6502/src/System.hxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: System.hxx,v 1.7 2005-06-21 05:00:46 urchlay Exp $
+// $Id: System.hxx,v 1.8 2005-07-09 00:59:13 urchlay Exp $
 //============================================================================
 
 #ifndef SYSTEM_HXX
@@ -47,7 +47,7 @@ class Deserializer;
         dynamic code for that page of memory.
 
   @author  Bradford W. Mott
-  @version $Id: System.hxx,v 1.7 2005-06-21 05:00:46 urchlay Exp $
+  @version $Id: System.hxx,v 1.8 2005-07-09 00:59:13 urchlay Exp $
 */
 class System
 {
@@ -242,6 +242,18 @@ class System
     */
     void poke(uInt16 address, uInt8 value);
 
+    /**
+      Force a poke to the TIA, bypassing the normal device selection.
+      This is used by the 3E and 3F bankswitch schemes, which attach
+      themselves to the address space at $00-$3F and need a way to
+      pass a poke there through to the TIA.
+
+      I don't know what the correct way to do this is, but I'm pretty
+      certain this ain't it. As soon as I do know, this method goes away.
+                                                            -- B.
+    */
+    void System::tiaPoke(uInt16 addr, uInt8 value);
+
   public:
     /**
       Structure used to specify access methods for a page

stella/src/emucore/stella.pro

@@ -3,6 +3,20 @@
 "Cartridge.Type" "3E"
 ""
 
+"Cartridge.MD5" "9b150a42fc788960fbb4cbe250259ee2"
+"Cartridge.Name" "3E Bankswitch Test (TIA @ $40)"
+"Cartridge.Manufacturer" "Kroko"
+"Cartridge.Type" "3E"
+"Display.Format" "PAL"
+""
+
+"Cartridge.MD5" "792b1d93eb1d8045260c840b0688ec8f"
+"Cartridge.Name" "3E Bankswitch Test (TIA @ $00)"
+"Cartridge.Manufacturer" "Kroko"
+"Cartridge.Type" "3E"
+"Display.Format" "PAL"
+""
+
 "Cartridge.MD5" "0685bd0bcb975ceef7041749a5454a48"
 "Cartridge.Name" "11 Sprite Demo (Piero Cavina) (PD)"
 "Cartridge.Manufacturer" "Piero Cavina"