论文部分内容阅读
ROM (Read Only Memory)在微机中占着举足轻重的地位,除具有POST(上电自检)等功能的系统ROM外,一些外设也配备了各自的ROM。ROM BIOS是一组底层固化程序,包括一些重要的数据参数。VGA的ROM BIOS是由不同厂家生产的VGA显示卡提供的,用户通过在寄存器中给定参数,发一条软件中断指令(INT 10H)来调用VGA ROM BIOS提供的功能。笔者在为理德排版系统编写显示驱动程序时,发现某些VGA卡上的ROM存在着错误!VESA(视频电子标准协会)制定并提供了一组附加的BIOS功能,这组功能以标准方式访问Super VGA扩充的模式与功能。其中的子功能05H——显示存储器窗口控制,提供了一种通用的方法来选取/读出显示存储页,用户不必关心正在使用的是哪一种显示卡(不同制造商生产的显示卡的分页方法也不同)。事情从此真
ROM (Read Only Memory) occupies a pivotal position in the microcomputer. In addition to the system ROM with POST (Power On Self Test) and other functions, some peripherals are also equipped with their own ROM. ROM BIOS is a set of underlying curing procedures, including some important data parameters. The ROM BIOS of VGA is provided by the VGA display card produced by different manufacturers. The user sends a software interrupt instruction (INT 10H) to call the function provided by VGA ROM BIOS by giving the parameters in the register. When I was writing a display driver for the Reed-typesetting system, I found an error in the ROM on some VGA cards! VESA (Video Electronics Standards Association) developed and provided an additional set of BIOS features that are accessed in the standard way Super VGA extended modes and features. The submenus 05H - Display memory window controls provide a versatile way to select / read memory pages for display. The user does not have to worry about which type of display card is in use (panes of video cards produced by different manufacturers Method is different). Things from true