README.md

@@ -16,12 +16,11 @@ Any help or suggestion is welcome!
   - [x] NoMBC
   - [x] MBC1
   - [x] MBC2
-  - [ ] MBC3 (partially implemented)
+  - [ ] MBC3
-  - [X] MBC5
+  - [ ] MBC5
   - [ ] MBC6
   - [ ] MBC7
   - [ ] HuC1
-- [ ] Save files
 - [ ] Web Assembly support (because this is a Rust project and it has to support Web Assembly)
 - [ ] Gameboy boot ROM (Not important for now)
 - [ ] Gameboy Color compatibility

src/ppu.rs

@@ -306,7 +306,9 @@ impl PPU {
             self.lcd_control = data;
             // Check if LCD is being turned on or off
             self.lcd_enable = get_bit(data, BitIndex::I7);
-            if !get_bit(data, BitIndex::I7) || (get_bit(data, BitIndex::I7) && !get_bit(self.lcd_control, BitIndex::I7)) {
+            if (get_bit(data, BitIndex::I7) && !get_bit(self.lcd_control, BitIndex::I7)) ||
+               !get_bit(data, BitIndex::I7)
+            {
                 self.io_registers[LCD_Y_ADDRESS as usize - 0xFF40] = 0x00;
                 // Set Hblank
                 let byte = self.io_registers[LCD_STATUS_ADDRESS as usize - 0xFF40];
@@ -364,7 +366,6 @@ impl PPU {
             }
         } else if self.lcd_y >= 144 && !self.get_lcd_status(LCDStatus::ModeFlag(LCDStatusModeFlag::VBlank)) {
             // Mode 1 Vertical blank
-            self.window_y_counter = 0;
             self.set_lcd_status(LCDStatus::ModeFlag(LCDStatusModeFlag::VBlank), true);
             self.set_interrupt(Interrupt::VBlank, true);
             self.stat_interrupt();
@@ -381,6 +382,7 @@ impl PPU {
             // Frame completed
             if self.lcd_y > 153 {
                 self.lcd_y = 0;
+                self.window_y_counter = 0;
             }
             self.force_set_register(LCD_Y_ADDRESS, self.lcd_y);
             self.stat_interrupt();

src/rom.rs

@@ -65,7 +65,6 @@ pub fn load_rom(filename: &str) -> std::io::Result<Box<dyn ROM>> {
         MBC::MBC1 => Box::new(MBC1::new(data, info)),
         MBC::MBC2 => Box::new(MBC2::new(data, info)),
         MBC::MBC3 => Box::new(MBC3::new(data, info)),
-        MBC::MBC5 => Box::new(MBC5::new(data, info)),
         _ => unimplemented!(),
     })
 }
@@ -92,7 +91,7 @@ enum Region {
     NonJapanese,
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug)]
 enum BankingMode {
     Simple,
     Advanced,
@@ -195,10 +194,6 @@ impl ROMInfo {
         }
     }
 
-    pub fn rom_size(&self) -> usize {
-        0x4000 * self.rom_banks as usize
-    }
-
     pub fn ram_size(&self) -> usize {
         0x2000 * self.ram_banks as usize
     }
@@ -245,7 +240,6 @@ pub struct MBC1 {
     rom_bank: u16,
     ram_bank: u8,
     ram_enable: bool,
-    is_large_rom: bool,
     banking_mode: BankingMode,
 }
 
@@ -256,8 +250,7 @@ impl MBC1 {
         println!("Has RAM {}", info.has_ram);
         println!("ROM banks {}", info.rom_banks);
         println!("RAM banks {}", info.ram_banks);
-        let ram = vec![0; info.ram_size() as usize];
+        let ram = Vec::with_capacity(info.ram_size() as usize);
-        let is_large_rom = info.rom_size() >= 1048576;
         Self {
             data,
             info,
@@ -265,73 +258,31 @@ impl MBC1 {
             rom_bank: 1,
             ram_bank: 0,
             ram_enable: false,
-            is_large_rom,
             banking_mode: BankingMode::Simple,
         }
     }
 
-    fn switch_rom_bank(&mut self, bank: u8) {
+    fn switch_rom_bank(&mut self, bank: u16) {
-        self.rom_bank = bank as u16 & 0b11111;
+        self.rom_bank = bank;
-        if self.rom_bank == 0 {
-            self.rom_bank = 1;
-        }
         if self.rom_bank > self.info.rom_banks.saturating_sub(1) {
             self.rom_bank = self.info.rom_banks.saturating_sub(1);
+        } else if self.rom_bank == 0 {
+            self.rom_bank = 1;
         }
-        //println!("switched to ROM bank {}", self.rom_bank);
-    }
-
-    fn switch_ram_bank(&mut self, bank: u8) {
-        self.ram_bank = bank & 0b11;
-        // println!("switched to RAM bank {}", self.ram_bank);
-    }
-
-    fn get_bank_zero_address(&self, address: u16) -> usize {
-        if !self.is_large_rom {
-            return address as usize;
-        }
-        match self.banking_mode {
-            BankingMode::Simple => address as usize,
-            BankingMode::Advanced => {
-                ((self.ram_bank as usize) << 5) * ((address & 0x3FFF) as usize)
-            },
-        }
-    }
-
-    fn get_bank_switchable_address(&self, address: u16) -> usize {
-        if self.is_large_rom {
-            let rom_bank = ((self.ram_bank as u16) << 5) | (self.rom_bank & 0b11111);
-            return ((rom_bank as usize) << 14) | (address & 0x3FFF) as usize;
-        }
-        return ((self.rom_bank as usize) << 14) | (address & 0x3FFF) as usize;
-    }
-
-    fn get_ram_address(&self, address: u16) -> usize {
-        let bank = match self.banking_mode {
-            BankingMode::Simple => 0,
-            BankingMode::Advanced => self.ram_bank,
-        };
-        ((bank as usize) << 11) + ((address as usize) & 0x1FFF)
     }
 }
 
 impl ROM for MBC1 {
     fn read(&self, address: u16) -> u8 {
         if BANK_ZERO.contains(&address) {
-            return match self.data.get(self.get_bank_zero_address(address)) {
+            return self.data[address as usize];
-                Some(byte) => *byte,
-                None => 0xFF,
-            };
         } else if BANK_SWITCHABLE.contains(&address) {
-            return match self.data.get(self.get_bank_switchable_address(address)) {
+            return self.data[((self.rom_bank as usize * 0x4000) + (address as usize & 0x3FFF)) as usize];
-                Some(byte) => *byte,
-                None => 0xFF,
-            };
         } else if EXTERNAL_RAM.contains(&address) {
-            if !self.info.has_ram || !self.ram_enable {
+            if !self.info.has_ram {
                 return 0xFF;
             }
-            return match self.ram.get(self.get_ram_address(address)) {
+            return match self.ram.get((address - EXTERNAL_RAM.min().unwrap() + (0x2000 * self.ram_bank as u16)) as usize) {
                 Some(data) => *data,
                 None => 0xFF,
             };
@@ -350,22 +301,26 @@ impl ROM for MBC1 {
             };
             return;
         } else if address >= 0x2000 && address <= 0x3FFF { // ROM bank number register
-            self.switch_rom_bank(data);
+            // println!("Switch bank to {:02X}", data);
+            self.switch_rom_bank(data as u16 & 0b00011111);
         } else if address >= 0x4000 && address <= 0x5FFF { // ROM and RAM bank number register
-            self.switch_ram_bank(data);
+            // println!("RAM bank {:02X}", data);
+            self.ram_bank = data & 0b11;
         } else if address >= 0x6000 && address <= 0x7FFF { // Banking mode select
-            self.banking_mode = match (data & 1) == 0 {
+            self.banking_mode = match data & 1 {
-                true => BankingMode::Simple,
+                0 => BankingMode::Simple,
-                false => BankingMode::Advanced,
+                1 => BankingMode::Advanced,
+                _ => unreachable!(),
             }
         } else if EXTERNAL_RAM.contains(&address) {
             if !self.ram_enable || !self.info.has_ram {
                 return;
             }
-            let address = self.get_ram_address(address);
+            let address = address as usize - EXTERNAL_RAM.min().unwrap() as usize + (EXTERNAL_RAM.min().unwrap() as usize * self.ram_bank as usize);
             if let Some(elem) = self.ram.get_mut(address) {
                 *elem = data;
             }
+            self.switch_rom_bank(self.rom_bank + (data as u16 >> 5));
         }
     }
 }
@@ -375,6 +330,7 @@ pub struct MBC2 {
     info: ROMInfo,
     ram: Vec<u8>,
     rom_bank: u16,
+    ram_bank: u8,
     ram_enable: bool,
 }
 
@@ -385,18 +341,19 @@ impl MBC2 {
         println!("Has RAM {}", info.has_ram);
         println!("ROM banks {}", info.rom_banks);
         println!("RAM banks {}", info.ram_banks);
-        let ram = vec![0; 0x200];
+        let ram = Vec::with_capacity(info.ram_size() as usize);
         Self {
             data,
             info,
             ram,
             rom_bank: 1,
+            ram_bank: 0,
             ram_enable: false,
         }
     }
 
     fn switch_rom_bank(&mut self, bank: u16) {
-        self.rom_bank = bank & 0b1111;
+        self.rom_bank = bank;
         if self.rom_bank > self.info.rom_banks.saturating_sub(1) {
             self.rom_bank = self.info.rom_banks.saturating_sub(1);
         } else if self.rom_bank == 0 {
@@ -410,22 +367,23 @@ impl ROM for MBC2 {
         if BANK_ZERO.contains(&address) {
             return self.data[address as usize];
         } else if BANK_SWITCHABLE.contains(&address) {
-            return self.data[((self.rom_bank as usize * 0x4000) + (address as usize % 0x4000)) as usize];
+            return self.data[((self.rom_bank as usize * 0x4000) + (address as usize & 0x3FFF)) as usize];
-        } else if address >= 0xA000 {
+        } else if address >= 0xA000 && address <= 0xA1FF {
-            let address = (address as usize) & 0x1FF;
+            if !self.info.has_ram || !self.ram_enable {
-            if !self.ram_enable {
                 return 0xFF;
             }
-            return match self.ram.get(address as usize) {
+            return match self.ram.get((address - EXTERNAL_RAM.min().unwrap() + (0x2000 * self.ram_bank as u16)) as usize) {
                 Some(data) => *data,
                 None => 0xFF,
             };
+        } else if address >= 0xA200 && address <= 0xBFFF {
+            return self.read(0xA000 + (address % 0x0200));
         }
         return 0xFF;
     }
 
     fn write(&mut self, address: u16, data: u8) {
-        if BANK_ZERO.contains(&address) {
+        if BANK_SWITCHABLE.contains(&address) {
             if address.to_be_bytes()[0] & 1 == 0 {
                 match data {
                     0x0A => self.ram_enable = true,
@@ -434,14 +392,6 @@ impl ROM for MBC2 {
             } else {
                 self.switch_rom_bank(data as u16);
             }
-        } else if address >= 0xA000 {
-            if !self.ram_enable {
-                return;
-            }
-            let address = address & 0x1FF;
-            if let Some(elem) = self.ram.get_mut(address as usize) {
-                *elem = data;
-            }
         }
     }
 }
@@ -462,7 +412,7 @@ impl MBC3 {
         println!("Has RAM {}", info.has_ram);
         println!("ROM banks {}", info.rom_banks);
         println!("RAM banks {}", info.ram_banks);
-        let ram = vec![0; info.ram_size() as usize];
+        let ram = Vec::with_capacity(info.ram_size() as usize);
         Self {
             data,
             info,
@@ -521,75 +471,3 @@ impl ROM for MBC3 {
 
     }
 }
-
-pub struct MBC5 {
-    data: Vec<u8>,
-    info: ROMInfo,
-    ram: Vec<u8>,
-    rom_bank: u16,
-    ram_bank: u8,
-    ram_enable: bool,
-}
-
-impl MBC5 {
-    fn new(data: Vec<u8>, info: ROMInfo) -> Self {
-        println!("MBC {:?}", info.mbc);
-        println!("Region {:?}", info.region);
-        println!("Has RAM {}", info.has_ram);
-        println!("ROM banks {}", info.rom_banks);
-        println!("RAM banks {}", info.ram_banks);
-        let ram = vec![0; info.ram_size() as usize];
-        Self {
-            data,
-            info,
-            ram,
-            rom_bank: 1,
-            ram_bank: 0,
-            ram_enable: false,
-        }
-    }
-}
-
-impl ROM for MBC5 {
-    fn read(&self, address: u16) -> u8 {
-        if BANK_ZERO.contains(&address) {
-            return self.data[address as usize];
-        } else if BANK_SWITCHABLE.contains(&address) {
-            return match self.data.get(((self.rom_bank as usize * 0x4000) + (address as usize % 0x4000)) as usize) {
-                Some(byte) => *byte,
-                None => 0xFF,
-            };
-        } else if EXTERNAL_RAM.contains(&address) {
-            if !self.info.has_ram || !self.ram_enable {
-                return 0xFF;
-            }
-            return match self.ram.get(((self.ram_bank as usize * 0x2000) + (address as usize % 0x2000)) as usize) {
-                Some(data) => *data,
-                None => 0xFF,
-            };
-        }
-        return 0xFF;
-    }
-
-    fn write(&mut self, address: u16, data: u8) {
-        if address <= 0x1FFF {
-            match data & 0b1111 {
-                0x0A => self.ram_enable = true,
-                _ => self.ram_enable = false,
-            };
-        } else if address >= 0x2000 && address <= 0x2FFF {
-            self.rom_bank = data as u16;
-        } else if address >= 0x3000 && address <= 0x3FFF {
-            self.rom_bank = ((data & 1) as u16) | (self.rom_bank & 0xF);
-        } else if address >= 0x4000 && address <= 0x5FFF {
-            self.ram_bank = data & 0b1111;
-        } else if EXTERNAL_RAM.contains(&address) {
-            if !self.ram_enable || !self.info.has_ram {
-                return;
-            }
-            if let Some(elem) = self.ram.get_mut(((self.ram_bank as usize * 0x2000) + (address as usize % 0x2000)) as usize) {
-                *elem = data;
-            }
-        }
-    }
-}