MDM now triggers a bankswitch on hotspot writes, which was

actually in the original spec.


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@2999 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

Changes.txt

@@ -12,6 +12,14 @@
                                Release History
 ===========================================================================
 
+4.1.1 to 4.2: (xxx xx, 2014)
+
+  * Fixed 'MDM' scheme to trigger bankswitching on writes to hotspots
+    (previously it only triggered on reads).
+
+-Have fun!
+
+
 4.1 to 4.1.1: (September 14, 2014)
 
   * Re-added 'uipalette' option due to popular demand (of at least one
@@ -21,8 +29,6 @@
     an annoying system beep.  Currently this is fixed by patching the SDL2
     library and including a modified version with Stella.
 
--Have fun!
-
 
 4.0 to 4.1: (September 1, 2014)
 

src/emucore/CartMDM.cxx

@@ -76,7 +76,7 @@ void CartridgeMDM::install(System& system)
   myHotSpotPageAccess[7] = mySystem->getPageAccess(0x0F00 >> shift);
 
   // Set the page accessing methods for the hot spots
-  System::PageAccess access(this, System::PA_READ);
+  System::PageAccess access(this, System::PA_READWRITE);
   for(uInt32 i = 0x0800; i < 0x0FFF; i += (1 << shift))
     mySystem->setPageAccess(i >> shift, access);
 
@@ -98,12 +98,12 @@ uInt8 CartridgeMDM::peek(uInt16 address)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool CartridgeMDM::poke(uInt16 address, uInt8 value)
 {
-  // Currently, writing to the hotspots is disabled, so we don't need to
-  // worry about bankswitching
-  // However, all possible addresses can appear here, and we only care
+  // All possible addresses can appear here, but we only care
   // about those below $1000
   if(!(address & 0x1000))
   {
+    bank(address & 0x0FF);
+
     int hotspot = ((address & 0x0F00) >> 8) - 8;
     myHotSpotPageAccess[hotspot].device->poke(address, value);
   }

src/emucore/CartMDM.hxx

@@ -33,8 +33,8 @@
 
     http://atariage.com/forums/topic/56073-cheap-2k4k-x-in-1-menu-driven-multicart-for-atari-2600
 
-  The hotspots in this scheme read from addresses $800 to $FFF, where the
-  lower byte determines the actual 4K bank switch to.  In the current
+  The hotspots in this scheme are read/write at addresses $800 to $FFF, where
+  the lower byte determines the actual 4K bank switch to.  In the current
   implementation, only 128 banks are supported, so selecting bank 128+ results
   in further bankswitching being locked.  A reset line is used to reset to
   bank 0 and re-enable bankswitching.