Summary of SO 11 Gestion Entrada Salida

00:00:00 - 00:35:00

This video explains how an operating system manages entry and exit for different devices that are connected to a computer system. It discusses how this function is important for ensuring that data is properly input and outputted, and provides an overview of how this process works.

• 00:00:00 This video discusses one of the functions of operating systems: managing entry and exit. This function is very important in computer systems, because a computer system is composed of a series of elements and devices beyond the main processing and memory core. In traditional computer systems, processors and memory are the only elements that are constantly used and can store data temporarily. Data is also input from different sources and outputs to different media. As time goes on, in computer systems new ways of inputting data have been added, such as keyboard and mouse. However, other ways of entering data have also been introduced over time, such as touch screens on computer monitors. In traditional computer systems, we have used printers and screens as outputs for data. However, there are now other devices that are outputs, such as Projectors. These devices can also be used for inputting data, but they are not always readable by humans. In the future, devices that are both readable and writable by humans will be more common. Until then, these devices are appropriate for communicating with distant devices. Eventually, data that is communicated through these devices will be inputted directly by the user. This is the edition that you are seeing when you are watching this video. We cannot imagine all the different devices that a computer
• 00:05:00 This video provides an overview of the three main types of computer systems: input/output (I/O), storage devices, and printers. It discusses the various differences between these systems, and how the operating system handles I/O operations. It also provides a table summarizing the differences in input and output (I/O) speeds between different types of devices.
• 00:10:00 The video discusses different ways in which computer systems handle data, noting that some devices, such as printers, are very slow. If what the user needs to do is save the document to a disk drive, the process will be blocked for a long time because the disk drive is slow. However, if the user needs to write on a magnetic disk, the process will take much less time, for example, than printing would. The time the process will be blocked is significan
• 00:15:00 In order to manage entries and exits with devices, three ways of doing this can be programmed, where one option is to have a predetermined entry and exit procedure programmed into the processor, which will then issue an order to a module of entry and exit. There are two ways of doing this: one is where the entry and exit procedure is programmed into the device itself, and the other is where direct access to the devices is used. In the latter case, the processor and device are not paused or interrupted, allowing the device to continue processing even if the entry and exit procedure is critical for termination. The third way is to use multi-threading techniques to manage different threads of processing for devices, where one thread is devoted to the entry and exit operation being performed. This method is also used to manage printing, writing to a disk, or printing to any printer. Another advance in this evolution is that the processor is not idle when there are no device interactions, because it isolates itself from the details of device interaction. If a process has been interrupted because it needs to read or write a device, the process is interrupted, but the system's functionality continues.
• 00:20:00 This video explains the concept of "bus" in computer systems, and how it enables devices like printers and input devices to operate independently from the main processor. In recent years, bus technology has been evolving, and increasingly devices that connect to a computer, such as printers and input devices, are becoming more autonomous. This allows the main processor to focus on more important tasks, freeing up resources for the user.
• 00:25:00 The video discusses buses for devices that connect to parallel ports and cereals for each of these elements, with one controller per each. There is also a monitor for the processor that oversees inputs and outputs to those devices and transfers them to the bus so that data from whence they came can be transmitted to whence they should go, which could be disks, the processor, or memory. The idea is that this bus, like a Swiss watch, would manage communication between all of the devices, since one from any one of them could send data to any of the others. For the operating system to handle multiple operations of input and output in an information system, it uses the concept of channels, one channel of input and output being a concept we discussed before in the sense that instructions that the CPU processes and that must interface with devices of input and output can manage multiple simultaneous operations simultaneously. In order to do that, the operating system needs to communicate with the devices of input and output through a channel controller. Channel controllers manage a set of devices and the channel acts instead of the CPU managing these control units, producing detached results and allowing the operating system to control the input and output status of each operation. There are two types of channel input and output: selectors control high-speed devices
• 00:30:00 The video discusses the importance of multiprogramming and how it is implemented in computer systems. It explains that when designing an input/output system, one important concept to consider is the use of shared memory between processes. This allows processes to be loaded into faster devices while other processes are active and waiting to complete their operations. Another way to improve the performance of a system is to exchange data between memory and the processor, which is infinitely faster than in most devices we've seen in the past. When designing an I/O system, the concept of multiprogramming is reinforced by ensuring that many active processes are loaded into memory and blocked while other processes are executing. This way, the processor can be kept busy while the data is loaded into memory and unloaded when it is used. In addition, the system should also inform the user when data is being stored and exchanged between devices, so that the user knows which devices are faster and which will allow for faster program execution. Finally, the video discusses the structure that an input/output module should have in order to optimize the performance of devices.
• 00:35:00 This video discusses how to set up an operating system, and covers the importance of having a controller for each device that enters or exits the machine. Sometimes this is included in the operating system itself, while other times it is installed on the device when it is first used. Hardware such as keyboards and mice also have controllers, and the operating system's main system-level entry and exit point is also known as a "controller." Any operating system, like Windows, Linux, or MacOS, can be controlled this way. In this part of the video, we discuss theoretical topics in forums, and we will continue exchanging concepts on this topic until the next video.