mbc5 ram address fix

src/processor/memory/rom/mbcs/mbc5.rs

@@ -8,6 +8,7 @@ pub struct Mbc5 {
     rom_size: usize,
     ram: Option<Vec<u8>>,
     ram_bank: u8,
+    ram_size: usize,
     ram_enabled: bool,
 }
 
@@ -20,6 +21,7 @@ impl Mbc5 {
             rom_size: rom_banks(rom_size) * ROM_BANK_SIZE,
             ram,
             ram_bank: 0,
+            ram_size: ram_size_kb(ram_size).map_or(1, |s| s * KB),
             ram_enabled: false,
         }
     }
@@ -36,7 +38,7 @@ impl Mbc5 {
     }
 
     fn get_ram_addr(&self, address: Address) -> usize {
-        address as usize + (RAM_BANK_SIZE * self.ram_bank as usize)
+        ((address as usize - 0xA000) + (RAM_BANK_SIZE * self.ram_bank as usize)) % self.ram_size
     }
 }