Simple thread poll allow the ready output to be passed for checking by giving it to the bus that is free and then the output is sent along the thread. The bus can send the output depending on the time that has been given and during the transfer the user won’t be able to perform any other operation. The input is given after finding out the bus is free or not and if it free then a check is made to see that the input exists or not. This thread poll is easy to understand but it is not efficient method to allow the data to be put over the bus manually. The problem of not doing multi-tasking can occur due to doing one task at a time. The method is only be used when input/output occurs at interval that are infrequent.