{"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":42,"pdf_page":58,"physical_index":58,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"38c22afdbaeb8b970c7cde5c4a5490c41ce454e107b645c683b84fd1dc18fc5a"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"尽管萨缪尔·莫尔斯在1836年通知过专利局，他成功发明了电报机，但是直到1843年，他才说服美国国会，为其创建了一个公共基金。1844年5月24日，这是历史性的一天，当华盛顿特区和马里兰州巴尔迪摩市之间的电报线路架设完成时，一条信息被成功地传递，内容是圣经中的句子：“What hath God wrought!”\n\n传统电报机中用来发送信息的电键，其外形如下图所示。\n\n它虽然外表奇特，其实只是一个被设计成有“最大开闭速度”的开关而已。如果需要长时间使用电键，最舒适的方法是，用拇指，食指和中指握住手柄，轻击它使其上下移动。保持电键的按下状态一小段时间，就会产生一个“点”的莫尔斯码。按下状态保持的时间更长一些就会产生一个“划”的莫尔斯码。\n\n线路的另一端是一个接收器，它主要是由一块电磁铁拉动一根金属杆构成的。最初电磁铁控制的是一只钢笔。有一个装置通过使用一个压紧的弹簧来拉动一卷纸经过设备，与电磁铁连接着的钢笔就会弹起或落下，在纸上画出点和划。能读懂莫尔斯电码的人员就可以把这些“点”和“划”译成字母和单词了。\n\n当然，我们人类是个懒惰的物种，电报操作员们很快发现，他们可以很容易地通过听钢笔弹起和落下的声音来翻译电码。在传统电报机中的“发声器”的帮助下，钢笔最终被废弃，整个装置看起来如下图所示。\n\n编码——隐匿在计算机软硬件背后的语言\n\n42","previous_page":null,"next_page":43}