Revert "Add "stc89a" protocol"

This reverts commit c5d509d1fa.

stcgal/protocols.py

@@ -225,8 +225,6 @@ class StcBaseProtocol(ABC):
             mcu_name += "E" if self.status_packet[17] < 0x70 else "W"
             self.model = self.model._replace(name = mcu_name)
 
-        self.bsl_version = self.status_packet[17]
-
     def get_status_packet(self):
         """Read and decode status packet"""
 
@@ -385,10 +383,6 @@ class StcAutoProtocol(StcBaseProtocol):
         else:
             self.protocol_name = None
 
-        # STC89 devices with BSL version 7.x.x have a slightly different protocol
-        if self.protocol_name == "stc89" and self.bsl_version >= 0x70:
-            self.protocol_name = "stc89a"
-
     def initialize_options(self, status_packet):
         raise NotImplementedError
 
@@ -613,22 +607,6 @@ class Stc89Protocol(StcBaseProtocol):
         print("done")
 
 
-class Stc89AProtocol(Stc89Protocol):
-    """STC89 protocol variant with different framing"""
-
-    def extract_payload(self, packet):
-        """Verify the checksum of packet and return its payload"""
-
-        packet_csum, = struct.unpack(">H", packet[-3:-1])
-        calc_csum = sum(packet[2:-3]) & 0xffff
-        if packet_csum != calc_csum:
-            self.dump_packet(packet)
-            raise StcFramingException("packet checksum mismatch")
-
-        payload = StcBaseProtocol.extract_payload(self, packet)
-        return payload[:-3]
-
-
 class Stc12AOptionsMixIn:
     def program_options(self):
         print("Setting options: ", end="")