A computer terminal is a computer or computer system used to let users input data and display their calculation results. Some terminals are all electronic, some are electromechanical. It is also called terminal. It is different from an independent computer.
Computer terminal is a computer or computer system used to let users input data and display their calculation results. Some terminals are all electronic, some are electromechanical. It is also called terminal. It is different from an independent computer.
终端其实就是一种输入输出设备，相对于计算机主机而言属于外设，本身并不提供运算处理功能。早期的计算机终端一般是机电的电传打字机，比如 ASR33。但是对于大多数应用来说它们太慢了。1970 年代初许多电脑公司认识到电视输入终端比穿孔卡片要好得多，而且可以使得计算机更加容易与用户互动，产生新的应用。当时的毛病在于相对于当时的小型计算机来说要显示一页文字所需要的内存太大了。在集成电路普及以前要显示电视信号所需要的速度对当时的逻辑门所提出的技术挑战也太高了。当时有一家公司宣布要生产一台价值 15,000 美元的视频终端，吸引了许多购户，但是最后它的工程师们决定这个计划无法完成。另一个解决方法是泰克公司发明的存储管，这台机器可以显示输出给它的信息，但是无法刷新。
The terminal is actually an I / O device, which belongs to peripheral equipment relative to the computer host, and does not provide operation processing function. Early computer terminals were typically electromechanical teletypewriters, such as asr33. But they are too slow for most applications. In the early 1970s, many computer companies realized that the TV input terminal is much better than the punch card, and it can make the computer easier to interact with users and generate new applications. The problem at that time was that the memory needed to display a page of text was too large for a small computer at that time. Before the popularization of IC, the speed required to display TV signal was too high for the technical challenge of logic gate at that time. At that time, a company announced to produce a $15000 video terminal, which attracted many buyers, but its engineers decided that the plan could not be completed. Another solution is a storage tube invented by tech. this machine can display the information output to it, but can’t refresh.
早期的视频终端使用特别的逻辑门，没有自己的中央处理器。发展微处理器的动机之一就是要简化终端里的电子组件的复杂性。大多数终端的屏幕是绿色或者橙色的，它们与大型计算机相连。典型的终端使用 RS-232 之类的串行数据通信与主机相连，IBM 使用它自己的系统网络体系结构协议通过同轴电缆来连接其主机与终端。
Early video terminals used special logic gates and did not have their own CPU. One of the motivations for developing microprocessors is to simplify the complexity of electronic components in terminals. Most terminals have green or orange screens, which are connected to the mainframe. The typical terminal uses serial data communication such as RS-232 to connect with the host, and IBM uses its own system network architecture protocol to connect its host and terminal through coaxial cable.
后来所谓的智能终端（如 VT52 和 VT100）被引入。今天依然有许多这两个终端的模拟软件。这些终端之所以被称为“智能”是因为它们理解转义序列，可以定位光标和控制显示位置。重要的非 VT100 终端有 IBM 3270、不同的慧智模型和 Tektronix 4014。1970 年代里世界上有十数个终端生产商，大多数终端的指令不兼容。1970 年代和 1980 年代初最重要的终端生产商有迪吉多、慧智、Televideo、利尔·西格勒公司和 Heathkit。
Later, so-called smart terminals (such as vt52 and VT100) were introduced. Today, there are still many simulation software for these two terminals. These terminals are called “smart” because they understand escape sequences, can locate cursors and control display positions. The important non VT100 terminals are IBM 3270, different wisdom models and Tektronix 4014. In the 1970s, there were more than ten terminal manufacturers in the world, most of which had incompatible instructions. The most important end producers in the 1970s and early 1980s were digido, Witz, televideo, lil segler and Heathkit.
早期的 IBM 个人计算机虽然也使用绿色的显示屏，但是它不算终端。个人计算机的显示屏不包括任何产生字母的硬件，所有的视频信号是在个人计算机的显卡里产生的。但是使用相应的模拟程序一台个人计算机可以与大型计算机相连模拟终端。最后使用微处理器的个人计算机大大地取消了对终端的需要。今天大多数个人计算机的 Telnet 用户端提供最普遍的终端（一般 VT100）的模拟。
Although the early IBM personal computer also used a green display, it was not a terminal. The display screen of the personal computer does not include any hardware to generate letters. All video signals are generated in the display card of the personal computer. But a personal computer can be connected with a large computer to simulate the terminal by using the corresponding simulation program. In the end, the personal computer using microprocessor has largely eliminated the need for terminal. Today, telnet clients of most personal computers provide simulation of the most common terminal (general VT100).