【正文】 , Center*2, Dashed, Dashed2, Dashed*2) the first is a half, the third line type for the standard form, the second line type that parison that the first line type is the first line type of two times, if line type the parison establish to is not suitable for, and would then make some exportation diagrams the line( such as the point lineation, dotted line...etc.) change into a solid line. Two, line breadth the count of establishPass by what handicraft painting, its painting with outs the diagram is a synchronous proceeding of, now calculator painting, its painting with outs the diagram divide a step proceeds. Wether draw the construction engineering diagram or machine spare parts diagram, at print control that a work that exportation engineering drawing, the most is a line to print the drawing the breadth, line the type, color, seal a line breadth for, and eachly growing to line type all contain its cowgirl, in the AutoCAD painting process of the old edition, even defined the line type the width, its at see the diagram area can39。s standard length, and show on held the act or at print the machine\ painting output, each length and ex portation parison with line type parison direct proportion. When show or print, the painting boundary that customer that request, this hour establish is out of accordance with the painting boundary of the province difference big, on held the act show or paint output39。t attain the request of the diagram paper, will adopt some techniqueiques to modify the related system to change to measure, and can make the calculator draw to attain the request of the diagram paper with output39。 Too sometimes the request of the diagram paper with make the diagram39。 However, using a mouse to trace a curve is not an easy task. There are three basic approaches to input an existing drawing。 畢業(yè)設(shè)計（論文） 外文譯文 院 （系）： 機電工程學(xué)院 專 業(yè)： 機械設(shè)計制造及其自動化 姓 名： 學(xué) 號： 指導(dǎo)教師評語： 簽名： 年 月 日 1 外語文獻翻譯 原文： HARDWARE Computers There are two major types of hardware used in a CAD system. Computer and input/output (I/O) devices. In the early days of CAD. Some mercial CAD systems used proprietary puters. Today, nearly all CAD software runs on a generalpurpose puter. Depending on the plexity of the CAD package, it may require a mainframe puter, a miniputer, or simply a microputer. In general, the more functionalities a CAD system provides, the more powerful the puter needed. Three dimensional solid modelers require much more puting than do twodimensional drafting systems。 thus, they need more powerful puters. Systems that integrate engineering analysis or simulation packages generally are more putationintensive. A powerful puter not only speeds up the response of a CAD system, but also can support multiple users without significant performance degradation. Several other parameters and ponents concerning the puter also have to be considered. CAD HARDWARE randomaccess memory (RAM)capacity permanent diskstorage capacity special graphics accelerator tape backups RAM is the actual physical memory (vs. virtual memory)of a puter. A small memory capacity means slow processing due to frequent swapping between the physical memory and the virtual memory on disk. Because CAD is extremely storage demanding, disk capacity is important. Small disk capacity limits the system to the storage of only a few drawings. CAD is graphic