• Vernacular takes you to open the door of operating system


    The origin of everything Turing machine Turing machine is mainly composed of data storage unit, control unit, operation unit and a read-write header for reading and writing external data.Turing machine work needs a paper tape, the paper tape is full of grid, can record characters on the grid, characters can be divided into data characters […]

  • Create a stable, fast and efficient free drawing bed


    GitHub + jsdelivr + picgo + imagine create a stable, fast, efficient and free drawing bed preface Why use a drawing bed? Because when publishing the same article on different platforms, the most painful point is the problem of image storage. The file storage methods of each platform are different, so it can’t be used […]

  • STM32 memory structure and FreeRTOS memory allocation skills


    This is my first time to use FreeRTOS to build STM32 project. I have stepped on many pitfalls and found that I lack the knowledge of memory and space allocation of the operating system, so I wrote down the document to record the learning results. Finally, the problem to be solved is how to properly […]

  • Learning canvas from a Sketchpad demo


    preface I started to learn canvas and made a Sketchpad application,The address is here. This article is some basic ideas and considerations of canvas, not basic API. It mainly lies in the practical experience of touch event Retina screen compatible Retina screen will use multiple physical pixels to render an independent pixel, resulting in double […]

  • Web storage for HTML5 local storage


    Before the advent of HTML5, if developers need to store a small amount of data in the client, they can only use cookies to achieve it, but there are several shortcomings in cookies The size of the cookie under each domain name is limited to 4KB.· cookies are included in each HTTP request, which results […]

  • Web storage


    Web storage Object to store client data object life cycle Storage size Communication with server Ease of use cookies Generally generated by the server, you can set the failure time. If the cookie is generated on the browser side, it will be invalid after closing the browser by default About 4K It will be carried […]

  • Ferroelectric random access memory fram and magnetic random access memory MRAM


    The new memory not only has the advantages of ram, but also has the characteristics of non-volatile. At the same time, it overcomes the disadvantages of non-volatile, such as slow writing speed and limited writing times. Ferroelectric random access memory (FRAM)The core technology of FRAM is ferroelectric crystal. This special material makes ferroelectric storage products have […]

  • Timing characteristics of SDRAM memory module


    SDRAM memory is widely used in many engineering projects, especially in radar, image processing and other data storage fields which need high speed and large capacity,SDRAM memoryIt has a wide range of application value. The single-chip SDRAM memory is usually directly soldered on the circuit board, and there are many pins. Once the SDRAM memory […]

  • Nonvolatile MRAM memory used in all levels of cache


    Reluctance random access memoryMRAMIt is a new type of memory, which has the advantages of fast reading speed, high integration and non-volatile. At present, many researches focus on the application of MRAM in computer storage system. At the same time, nonvolatile MRAM memory is also used in all levels of cache. MRAM replaces SRAM as L2 […]

  • Composition of MRAM cache


    Reluctance random access memory(MRAM)It is a new type of memory, which has the advantages of fast reading speed, high integration and non-volatile. At present, many researches focus on the application of MRAM memory in computer storage system. Because of its many advantages, MRAM has the potential to replace SRAM and DRAM. MRAM memory constructed with […]

  • New JavaScript syntax “double question mark syntax” and “optional chain syntax”


    Double question mark grammar Double question mark grammarThe concept is to return the value on the right when the value on the left is null or undefined let Form = undefined ?? true; //Form = true Alternative chain syntax ? optional chain //Optional chain let body = { value: { a: ‘123321’ } } let […]

  • 13-1-3 password management


    Password management in Django Password management is not reinvented when it is not necessary. Django is committed to providing a set of secure and flexible tools to manage user passwords. This document describes how Django stores passwords and hash storage method configurations, as well as some examples of using hash passwords. See also Even if […]