关于显存的

[gulongl6]

考证一段话：b8000～bffff共32k空间，是80×25模式下的显示缓冲区，分为8页，当前显示器显示第0页内容，也就是b8000～b8f9f中的4000个字节内容在显示器上被看到。
问题：写入1～7页的内容如何被看到？还有显存有什么用？

[romyks]

通过滚屏可能显示其它页的内容，显存是用来存放显示数据的，屏幕上显示的就是显存当前页的内容。

[dunkel]

应该是设置当前的显示页吧. 下面的内容是从 masm6.x 的帮助里复制出来的

Interrupt: 10h Function: 05h

Title: Set Display Page

See also: Get Video Mode, @SetPage

Description: [CGA] [PCjr] [EGA] [MCGA] [VGA]

Selects the active display page for the video display.

Input Output

For CGA, EGA, MCGA, VGA If CGA, EGA, MCGA, or
AH = 05h VGA adapter:
AL = Page None
0-7 for modes 00h and 01h (CGA,
EGA, MCGA, VGA) If PCjr and if
0-3 for modes 02h and 03h (CGA) function called with
0-7 for modes 02h and 03h (EGA, AL = 80h-83h
MCGA, VGA) BH = CRT page register
0-7 for mode 07h (EGA, VGA) BL = CPU page register
0-7 for mode 0Dh (EGA, VGA)
0-3 for mode 0Eh (EGA, VGA)
0-1 for mode 0Fh (EGA, VGA)
0-1 or mode 10h (EGA, VGA)

For PCjr only
AH = 05h
AL = Subfunction
80h = Read CRT/CPU page registers
81h = Set CPU page register
82h = Set CRT page register
83h = Set both CPU and CRT page
registers
BH = CRT Page (Subfunctions 82h and 83h)
BL = CPU Page (Subfunctions 81h and 83h)