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一、前言七十年代初以来,由于LSI技术的发展和各种性能微计算机的相继问世,作为计算机外围设备的显示终端,正经历着如下的演进过程:一、字符显示终端;二、图形显示终端;三、图像显示终端。前二者不仅多为黑白二值显示,很少有中间灰度(色调),且在形成各种线段或矢量时,多由硬部件产生。鉴于当前国内、外显示设备的研制情况及其发展趋向,在研制数字图像式CRT终端时对关键部件,诸如图像刷新随机存储器(RAM)、字符显示存贮器(RAM)、均采用大规模集成电路;在扫描方法上,采用电视光栅扫描方式;
I. Introduction Since the early 1970s, due to the development of LSI technology and the advent of various performance microcomputers, the display terminal as a computer peripheral device is experiencing the following evolution: 1. Character display terminal; 2. Graphic display Terminal; Third, the image display terminal. The first two are not only mostly black and white binary display, there is little intermediate gray (hue), and in the formation of a variety of line segments or vectors, mostly produced by the hardware components. In view of the development of domestic and foreign display devices and their development trend, key components such as image refresh RAM and character display memory (RAM) are used in the development of digital image CRT terminals, Circuit; in the scanning method, the use of television raster scanning;