《第一章计算机系统基础.ppt

例3：(13.6875)10 =(13)10+(0.6875)10 =(1101)2+(0.1011)2=(1101.1011)2 例4：(101.101)2 =1×22 + 0×21 +1×20 =4 + 0 + 1 + 0.5 + 0 + 0.125 = (5.625)10 + 1×2-1 + 0×2-2 +1×2-3 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 4、二进制与八进制、十六进制之间的相互转换 (1) 二进制数转换成八进制数：以小数点为分界点，左右三位一节，不足三位以零补足三位。 例:　(101101.01) 2=(101，101.010)=(55.2)8 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (2)八进制数转换成二进制数：将每位八进制数码以三位二进制数表示。 例:　(76.42) 8=(111110.100010)2=(111110.10001)2 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (3)二进制数转换成十六进制数：以小数点为分界点，左右每四位一节，不足四位以零补足四位。 (1111011011.100101011)2 = (11,1101,1011.1001,0101,1000)2 = (3DB.958)16 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (4)十六进制数转换成二进制数：将每位十六进制数码以四位二进制数表示。 例:　(A3B.C) 16 = (101000111011.1100)2 = (101000111011.11)2 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1.3.2、数值在计算机中的表示 计算机中的数据： ①数值型数据：128，(32.56)8； ②非数值型数据：“学生”、“0730-8845139”。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1. 计算机中数的有关概念 ① 数的长度 1字节（byte)=8比特（bit） 在计算机中，数的长度按比特（bit)来计算。但因存储容量常以“字节”为计量单位，所以数据长度也常以字节为单位计算。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 硬件系统举例： Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 软件系统举例： Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1.2.2 计算机硬件系统 运算器 控制器 存储器 输入设备 输出设备 从逻辑功能分为: Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd