{"resolved":true,"match_type":"uuid","source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","requested_by":"printed_page","book":{"source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","id":"38270854-596f-4a26-8183-db8c968c6020","uuid":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","normalized_title":"编码隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","isbns":["9787121181184","0123456789","6044921875","3039331000","0000000000","0000000000000"],"parsed":true,"ai_readable":true,"document_type":"book","page_count":438,"navigation_url":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020","title_url":"https://workshop.closeclaw.top/ai/title/%E7%BC%96%E7%A0%81%20%E9%9A%90%E5%8C%BF%E5%9C%A8%E8%AE%A1%E7%AE%97%E6%9C%BA%E8%BD%AF%E7%A1%AC%E4%BB%B6%E8%83%8C%E5%90%8E%E7%9A%84%E8%AF%AD%E8%A8%80","fixed_page_url_template":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","path_api_url_template":"https://workshop.closeclaw.top/api/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","read_url":"https://workshop.closeclaw.top/api/ai/read/38270854-596f-4a26-8183-db8c968c6020","page_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/page","search_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/search"},"page":{"printed_page":345,"pdf_page":361,"physical_index":361,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"7f125a925c690fa85868b721e6f3affdca011eb9d6c81cf8af73449de912abdc"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"微处理器不能直接从磁盘读取数据，需要将所需的数据从磁盘调入内存（随机访问存储器)，然后它才能对其访问，当然这需要额外的步骤。微处理器还需要执行一段小程序，这段程序会访问磁盘，并将数据从磁盘调入内存。\n\n关于随机访问存储器和磁介质存储器之间的差别，有个形象的比喻可以帮助我们加深理解：随机访问存储器就像办公桌的桌面，上面的任何东西都可以拿来直接使用；而磁介质存储器就像一个文件柜，里面的东西不能直接使用，如果想要使用放在文件柜里的某件东西，你需要站起来，走到文件柜前，查找需要的文件，然后带回桌面。如果桌面太拥挤，没有空间放置需要的文件，还需要把桌面上暂时不用的东西先放回到文件柜中。\n\n这个比喻恰到好处，实际上，存储在磁盘上的数据的确是以文件（files）作为实体来存放的。存储和检索文件是操作系统（OperatingSystem）很重要的一个功能，关于操作系统的相关知识，下一章将会进行专门介绍。\n\n21 总线\n\n345","previous_page":344,"next_page":null}