MegaCart support. Partial SGM support(except sound). #11 #45

drhelius · Dec 28, 2023 · 7ad976c · 7ad976c
1 parent 48eaab5
commit 7ad976c
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Showing 10 changed files with 285 additions and 60 deletions.
diff --git a/platforms/desktop-shared/emu.cpp b/platforms/desktop-shared/emu.cpp
@@ -355,6 +355,9 @@ static const char* get_mapper(Cartridge::CartridgeTypes type)
     case Cartridge::CartridgeColecoVision:
         return "ColecoVision";
         break;
+    case Cartridge::CartridgeMegaCart:
+        return "MegaCart";
+        break;
     case Cartridge::CartridgeNotSupported:
         return "Not Supported";
         break;

diff --git a/platforms/desktop-shared/gui.cpp b/platforms/desktop-shared/gui.cpp
@@ -72,6 +72,7 @@ static void menu_ffwd(void);
 static void show_info(void);
 static void show_fps(void);
 static Cartridge::CartridgeRegions get_region(int index);
+//static Cartridge::CartridgeTypes get_mapper(int index);
 
 void gui_init(void)
 {
@@ -1418,6 +1419,10 @@ static void show_fps(void)
 //             return Cartridge::CartridgeNotSupported;
 //         case 1:
 //             return Cartridge::CartridgeColecoVision;
+//         case 2:
+//             return Cartridge::CartridgeMegaCart;
+//         case 3:
+//             return Cartridge::CartridgeActivisionCart;
 //         default:
 //             return Cartridge::CartridgeNotSupported;
 //     }

diff --git a/platforms/desktop-shared/gui_debug.cpp b/platforms/desktop-shared/gui_debug.cpp
@@ -195,6 +195,17 @@ static void debug_window_memory(void)
     Cartridge* cart = core->GetCartridge();
     Video* video = core->GetVideo();
 
+    ImGui::PushFont(gui_default_font);
+
+    ImGui::TextColored(cyan, "  ROM: ");ImGui::SameLine();
+
+    ImGui::TextColored(magenta, "BANK");ImGui::SameLine();
+    ImGui::Text("$%02X", memory->GetRomBank()); ImGui::SameLine();
+    ImGui::TextColored(magenta, "  ADDRESS");ImGui::SameLine();
+    ImGui::Text("$%05X", memory->GetRomBankAddress());
+
+    ImGui::PopFont();
+
     if (ImGui::BeginTabBar("##memory_tabs", ImGuiTabBarFlags_None))
     {
         if (ImGui::BeginTabItem("BIOS"))
@@ -213,10 +224,18 @@ static void debug_window_memory(void)
             ImGui::EndTabItem();
         }
 
+        if (ImGui::BeginTabItem("SGM RAM"))
+        {
+            ImGui::PushFont(gui_default_font);
+            mem_edit.DrawContents(memory->GetSGMRam(), 0x8000, 0x0000);
+            ImGui::PopFont();
+            ImGui::EndTabItem();
+        }
+
         if (IsValidPointer(cart->GetROM()) && ImGui::BeginTabItem("ROM"))
         {
             ImGui::PushFont(gui_default_font);
-            mem_edit.DrawContents(cart->GetROM(), 0x8000, 0x8000);
+            mem_edit.DrawContents(cart->GetROM(), cart->GetROMSize(), 0x0000);
             ImGui::PopFont();
             ImGui::EndTabItem();
         }
@@ -576,11 +595,15 @@ static void debug_window_disassembler(void)
                 if (show_segment)
                 {
                     ImGui::SameLine();
-                    ImGui::TextColored(color_segment, "%s ", vec[item].record->segment);
+                    ImGui::TextColored(color_segment, "%s", vec[item].record->segment);
                 }
 
                 ImGui::SameLine();
-                ImGui::TextColored(color_addr, "%04X ", vec[item].record->address);
+                if (strcmp(vec[item].record->segment, "ROM") == 0)
+                    ImGui::TextColored(color_addr, "%02X:%04X ", vec[item].record->bank, vec[item].record->address);
+                else
+                    ImGui::TextColored(color_addr, "  %04X ", vec[item].record->address);
+
 
                 if (show_mem)
                 {

diff --git a/src/Audio.h b/src/Audio.h
@@ -34,6 +34,9 @@ class Audio
     void SetSampleRate(int rate);
     void SetVolume(float volume);
     void WriteAudioRegister(u8 value);
+    void SGMWrite(u8 value);
+    u8 SGMRead();
+    void SGMRegister(u8 reg);
     void Tick(unsigned int clockCycles);
     void EndFrame(s16* pSampleBuffer, int* pSampleCount);
     void SaveState(std::ostream& stream);
@@ -46,6 +49,8 @@ class Audio
     int m_iSampleRate;
     blip_sample_t* m_pSampleBuffer;
     bool m_bPAL;
+    u8 m_SGMRegister;
+    u8 m_SGMRegisters[16];
 };
 
 inline void Audio::Tick(unsigned int clockCycles)
@@ -58,4 +63,24 @@ inline void Audio::WriteAudioRegister(u8 value)
     m_pApu->write_data(m_ElapsedCycles, value);
 }
 
+inline void Audio::SGMWrite(u8 value)
+{
+    uint8_t mask[16] = {
+        0xFF, 0x0F, 0xFF, 0x0F, 0xFF, 0x0F, 0x1F, 0xFF,
+        0x1F, 0x1F, 0x1F, 0xFF, 0xFF, 0x0F, 0xFF, 0xFF,
+    };
+
+    m_SGMRegisters[m_SGMRegister] = value & mask[m_SGMRegister];
+}
+
+inline u8 Audio::SGMRead()
+{
+    return m_SGMRegisters[m_SGMRegister];
+}
+
+inline void Audio::SGMRegister(u8 reg)
+{
+    m_SGMRegister = reg & 0x0F;
+}
+
 #endif	/* AUDIO_H */
diff --git a/src/Cartridge.cpp b/src/Cartridge.cpp
@@ -116,6 +116,14 @@ void Cartridge::ForceConfig(Cartridge::ForceConfiguration config)
             m_Type = config.type;
             Log("Forcing Mapper: Colecovision");
             break;
+        case Cartridge::CartridgeMegaCart:
+            m_Type = config.type;
+            Log("Forcing Mapper: MegaCart");
+            break;
+        case Cartridge::CartridgeActivisionCart:
+            m_Type = config.type;
+            Log("Forcing Mapper: Activision");
+            break;
         default:
             break;
     }
@@ -304,7 +312,9 @@ bool Cartridge::LoadFromBuffer(const u8* buffer, int size)
 
         m_iCRC = CalculateCRC32(0, m_pROM, m_iROMSize);
 
-        return GatherMetadata(m_iCRC);
+        GatherMetadata(m_iCRC);
+
+        return true;
     }
     else
         return false;
@@ -317,45 +327,62 @@ bool Cartridge::GatherMetadata(u32 crc)
 
     Log("ROM Size: %d KB", m_iROMSize / 1024);
 
-    m_iROMBankCount = (m_iROMSize / 0x2000) + (m_iROMSize % 0x2000 ? 1 : 0);
+    m_iROMBankCount = (m_iROMSize / 0x4000) + (m_iROMSize % 0x4000 ? 1 : 0);
 
     Log("ROM Bank Count: %d", m_iROMBankCount);
 
+    m_Type = Cartridge::CartridgeNotSupported;
+
     int headerOffset = 0;
+    u16 header = m_pROM[headerOffset + 1] | (m_pROM[headerOffset + 0] << 8);
+    m_bValidROM = (header == 0xAA55) || (header == 0x55AA);
 
-    if (m_iROMSize > 0x8000)
+    if (header == 0x6699)
     {
-        Log("Cartridge is probably Mega Cart. ROM size: %d bytes", m_iROMSize);
-        headerOffset = m_iROMSize - 0x4000;
+        Log("Cartridge is a Colec Adam expansion ROM. Header: %X", header);
     }
 
-    u16 header = m_pROM[headerOffset + 1] | (m_pROM[headerOffset + 0] << 8);
-    m_bValidROM = (header == 0xAA55) || (header == 0x55AA);
-
-    if (m_bValidROM)
+    if (m_bValidROM && (m_iROMSize <= 0x8000))
     {
-        Log("ROM is Valid. Header found: %X", header);
+        m_Type = Cartridge::CartridgeColecoVision;
+        Log("Cartridge is Colecovision. ROM size: %d bytes.", m_iROMSize);
     }
-    else
+    else if (m_bValidROM && (m_iROMSize > 0x8000))
     {
-        Log("ROM is NOT Valid. No header found.");
+        m_Type = Cartridge::CartridgeActivisionCart;
+        Log("Cartridge is Mega Cart. ROM size: %d bytes. Banks %d.", m_iROMSize, m_iROMBankCount);
     }
+    else if (!m_bValidROM && (m_iROMSize > 0x8000))
+    {
+        headerOffset = m_iROMSize - 0x4000;
+        header = m_pROM[headerOffset + 1] | (m_pROM[headerOffset + 0] << 8);
+        m_bValidROM = (header == 0xAA55) || (header == 0x55AA);
 
-    if (header == 0x6699)
+        if (m_bValidROM)
+        {
+            m_Type = Cartridge::CartridgeMegaCart;
+            Log("Cartridge is Mega Cart. ROM size: %d bytes. Banks %d.", m_iROMSize, m_iROMBankCount);
+        }
+    }
+    else
     {
-        Log("Cartridge is a Colec Adam expansion ROM. Header: %X", header);
+        m_Type = Cartridge::CartridgeNotSupported;
+        Log("ROM is NOT Valid. No header found.");
     }
 
-    //m_Type = m_bValidROM ? Cartridge::CartridgeColecoVision : Cartridge::CartridgeNotSupported;
-    m_Type = Cartridge::CartridgeColecoVision;
-
     GetInfoFromDB(crc);
 
     switch (m_Type)
     {
         case Cartridge::CartridgeColecoVision:
             Log("ColecoVision mapper found");
             break;
+        case Cartridge::CartridgeMegaCart:
+            Log("MegaCart mapper found");
+            break;
+        case Cartridge::CartridgeActivisionCart:
+            Log("Activision mapper found");
+            break;
         case Cartridge::CartridgeNotSupported:
             Log("Cartridge not supported!!");
             break;

diff --git a/src/Cartridge.h b/src/Cartridge.h
@@ -29,6 +29,8 @@ class Cartridge
     enum CartridgeTypes
     {
         CartridgeColecoVision,
+        CartridgeMegaCart,
+        CartridgeActivisionCart,
         CartridgeNotSupported
     };
 

diff --git a/src/ColecoVisionIOPorts.h b/src/ColecoVisionIOPorts.h
@@ -72,6 +72,15 @@ inline u8 ColecoVisionIOPorts::In(u8 port)
         {
             return m_pInput->ReadInput(port);
         }
+        default:
+        {
+            if (port == 0x52)
+            {
+                return m_pAudio->SGMRead();
+                return 0xAA;
+            }
+            return 0xFF;
+        }
     }
 
     Log("--> ** Attempting to read from port $%X", port);
@@ -112,7 +121,28 @@ inline void ColecoVisionIOPorts::Out(u8 port, u8 value)
         }
         default:
         {
-            Log("--> ** Output to port $%X: %X", port, value);
+            if (port == 0x50)
+            {
+                m_pAudio->SGMRegister(value);
+                break;
+            }
+            else if (port == 0x51)
+            {
+                m_pAudio->SGMWrite(value);
+                break;
+            }
+            else if (port == 0x53)
+            {
+                m_pMemory->EnableSGMUpper(value & 0x01);
+            }
+            else if (port == 0x7F)
+            {
+                m_pMemory->EnableSGMLower(~value & 0x02);
+            }
+            else
+            {
+                Log("--> ** Output to port $%X: %X", port, value);
+            }
         }
     }
 }