Fix root cause of ALttP hardware crashes on collect. (ArchipelagoMW#2132)

As it turns out, SD2SNES / FXPAK Pro has a limit as to how many bytes can be written in a single command packet.  Exceed this limit, and the hardware will crash.  That limit is 512 bytes.  Even then, I have scaled back to 256 bytes at a time for a margin of safety.

Author: CaitSith2

SNIClient.py

@@ -565,14 +565,16 @@ async def snes_write(ctx: SNIContext, write_list: typing.List[typing.Tuple[int,
         PutAddress_Request: SNESRequest = {"Opcode": "PutAddress", "Operands": [], 'Space': 'SNES'}
         try:
             for address, data in write_list:
-                PutAddress_Request['Operands'] = [hex(address)[2:], hex(len(data))[2:]]
-                # REVIEW: above: `if snes_socket is None: return False`
-                # Does it need to be checked again?
-                if ctx.snes_socket is not None:
-                    await ctx.snes_socket.send(dumps(PutAddress_Request))
-                    await ctx.snes_socket.send(data)
-                else:
-                    snes_logger.warning(f"Could not send data to SNES: {data}")
+                while data:
+                    # Divide the write into packets of 256 bytes.
+                    PutAddress_Request['Operands'] = [hex(address)[2:], hex(min(len(data), 256))[2:]]
+                    if ctx.snes_socket is not None:
+                        await ctx.snes_socket.send(dumps(PutAddress_Request))
+                        await ctx.snes_socket.send(data[:256])
+                        address += 256
+                        data = data[256:]
+                    else:
+                        snes_logger.warning(f"Could not send data to SNES: {data}")
         except ConnectionClosed:
             return False