{"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":201,"pdf_page":217,"physical_index":217,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"f4a259868e043ab74c3f18e74ceb6013f90e2b2fbf27b5c5c8dcf6732ef0cb09"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"这个“额外装置”就是图中的神秘盒子，顶部带有8个输入端，左侧也带有3个输入端。通过三个开关的闭合和断开，对顶部的输入进行8选1操作，输出结果被传递到其底部连接的灯泡，使其发光。\n\n上图标注的“这是什么装置？”到底是什么呢？我们先前曾碰见过类似的东西，当时讨论的装置没有这么多的输入端。这种装置曾出现在第14章中第一个改进的加法机的电路中。在该电路中要在一行开关和一个锁存器的输出之间选择一个，作为加法器的输入，当时称其为2-1选择器。而我们现在所需要的正是8-1数据选择器（8-Line-to-1-LineData Selector)。\n\n8-1选择器有8个数据输入端（在其顶部），以及3个选择输入端（在其左侧）。选择输入端的功能就是选择一个输入端数据，然后使其在输出端输出。如果选择输入端为000，则将 ${ \\bf D } _ { 0 }$ 锁存器的值输出；若选择端为111，则 $\\mathbf { D } _ { 7 }$ 锁存器的值将被输出；若选择端为101，则相应地输出 $\\mathbf { D } _ { 5 }$ 的值。系统的真值表如下所示。\n\n16 存储器组织\n\n201","previous_page":200,"next_page":202}