SPOOLing is an abbreviation that means simultaneously peripheral functions that are performed on-line. It’s a buffering mechanism or method whereby data is temporarily stored to be utilized and then executed by a device, a program or system. The data is then kept in memory, or in other in volatile memory until the computer or program asks for it to be executed.
When working in a PC system,, peripheral devices, like printers , punch card readers and others (batch processing) are very slow in comparison to the overall performance components of the computer system. The process of transferring input and output to the system was soon spotted as an issue. Then comes the need for spool.
Spooling functions like a standard request queue in which information, instructions and processes from multiple sources are stored to execute later. It is generally stored in the computer’s physical memory buffers, or I/O device-specific interrupts. The spool process is in FIFO way i.e. any first instruction that is present within the queue is pop and executed.
Applications/Implementations of Spool:
1.) The most commonly used is the one that can be located in I/O devices such as mouse and keyboard printers. For instance, in a printer the files or documents which are sent to the printer first saved in memory or in the printer’s spooler. Once the printer is set it retrieves the information from the spool before printing it.
Have you ever had a moment when suddenly, for a few seconds, your keyboard or mouse stop functioning? In the meantime, we typically click repeatedly across the screen to see whether or not it is working. Once it does start working, whatever we clicked during the hang state is executed extremely quickly because the entire instruction was stored in the device’s spool.
2.) The batch processor makes use of the spooling technique to keep an inventory of jobs that are ready to run that can be initiated when the system has the capacity to handle them.
3.) Spooling has the capability of having the ability to overlap I/O operations for one task with processor operation for another task. i.e. multiple processes can create documents in an ink queue with no waiting for their turn and continue their work.
4.) E-mail: An email is transmitted by an MTA (Mail Transfer Agent) to an area of temporary storage in which it is awaiting for it to be picked up at an MA (Mail Agent) (Mail Agent)
5) Also, it can be used to generate Banner page (these are the pages that are used to print on computers to distinguish documents from one others and identify e.g. the printer who made the request via username, account number, or even the location of the bin to be picked up. These pages are commonly utilized in offices where several people are sharing the quantity of resources available).
