def get_np_rows(matrix, start_entry, x=512):
    """
    Returns the next x rows of a numpy array. 
    """
    arrays = []

    matrix_len = len(matrix)
    end_entry = start_entry + x

    if matrix_len < start_entry + x:
        end_entry = matrix_len 

    for i in range(start_entry, end_entry):
        arrays.append(matrix[i])
        
    return arrays, end_entry