AssemblyArraysV1.sol

pragma solidity ^0.5.10;

contract AssemblyArrays {
  
  bytes testArray;
  
  function getLength() public view returns (uint256) {
      return testArray.length;
  }
  
  function getElement(uint256 index) public view returns (bytes1) {
      return testArray[index];
  }
  
  function pushElement(bytes1 value) public {
      testArray.push(value);
  }
  
  function updateElement(bytes1 value, uint256 index) public {
      testArray[index] = value;
  }
}

AssemblyArraysV2.sol

pragma solidity ^0.5.10;

contract AssemblyArrays {
  
  bytes testArray;
  
  function getLength() public view returns (uint256) {
      bytes memory memoryTestArray = testArray;
      uint256 result;
      assembly {
         result := mload(memoryTestArray)
      }
      return result;
  }
  
  function getElement(uint256 index) public view returns (bytes1) {
      return testArray[index];
  }
  
  function pushElement(bytes1 value) public {
      testArray.push(value);
  }
  
  function updateElement(bytes1 value, uint256 index) public {
      testArray[index] = value;
  }
}

AssemblyArraysV3.sol

pragma solidity ^0.5.10;

contract AssemblyArrays {
  
  bytes testArray;
  
  function getLength() public view returns (uint256) {
      bytes memory memoryTestArray = testArray;
      uint256 result;
      assembly {
         result := mload(memoryTestArray)
      }
      return result;
  }
  
  function getElement(uint256 index) public view returns (bytes1) {
      uint256 length = getLength();
      require(index < length);
      bytes memory memoryTestArray = testArray;
      bytes1 result;
      assembly {
        let wordIndex := div(index, 32)
        let initialElement := add(memoryTestArray, 32)
        let resultWord := mload(add(initialElement, mul(wordIndex, 32)))
        let indexInWord := mod(index, 32)
        result := shl(mul(indexInWord, 8), resultWord)
      }
      return result;
  }
  
  function pushElement(bytes1 value) public {
      testArray.push(value);
  }
  
  function updateElement(bytes1 value, uint256 index) public {
      testArray[index] = value;
  }
}