BIOS 详细中断功能调用

System BIOS Interrupts

INT 10h Video Service

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00h Set Video Mode

01h Set Cursor Type

02h Set Cursor Position

03h Return Cursor Position

04h Return Light Pen Position

05h Set Current Video Page

06h Scroll Text Upward

07h Scroll Text Downward

08h Return Character or Attribute

09h Write Character or Attribute

0Eh Write Character

0Fh Return Video Display Mode

13h Write Character String

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Cont0

Index 1

INT 10h Video Service, Continued

Function 00h Set Video Mode

04h 320 x 200 four-color graphics, with CGA card

05h 320 x 200 monochrome, with CGA card

06h 640 x 200 monochrome, with CGA card

07h 80 x 25 monochrome, with monochrome card

Output: No registers set.

Description Function 00h sets the video mode. Only the video

modes supported in the MDA and CGA video standards

are supported by the system BIOS. This function

programs the CRTC, selects a default color palette, and

clears the video buffer if the proper flag is set in the save

2, 3 CGA 642x200 Text 16/256K 80x25 8x8 4 B800h

4, 5 CGA 320x200 Graphics 4/256K 40x25 8x8 1 B800h

6 CGA 640x200 Graphics 2/256K 80x25 8x8 1 B800h

7 MDA 720x350 Text None 80x25 9x14 1 B000h

Cont0

INT 10h Video Service, Continued

Function 01h Set Cursor Type

Description Function 01h sets the cursor type. If using MDA,

valid values are 0–13. Using CGA, valid values are 0–7.

If CH is 20h, the cursor is disabled. This function

programs the CRTC to display the text cursor type. Only

one cursor type is maintained for each video page. The

Function 02h Set Cursor Position

Input: AH = 02h

BH = Video Page Number

DH = Line on Screen

DL = Column on Screen

Output: No registers set. 40:50h is updated.

Description Function 02h positions the cursor in a video page.

Valid values for DH are 0 – 24. Valid values for DL are 0

– 39 in 40-column mode and 0 – 79 in 80-column mode.

If the current video page number is in BH, the BIOS

Index 3

INT 10h Video Service, Continued

Function 03h Return Cursor Position

DL = Column on Screen

Function 04h Return Light Pen Position

Input: AH = 04h

00h Position is unreadable

01h Position is readable

04h Light pen disabled or no valid address.

BX = Column on Graphic Screen (Pixel)

CH = Line on Graphic Screen (Raster Line)

CL = Raster line if resolution of mode is less than 200 lines.

DH = Line on text screen

DL = Column on text screen

eight (in 640 x 200 mode).

Cont0

INT 10h Video Service, Continued

Function 05h Set Current Video Page

Description Function 05h sets a new video page or selects the

portion of the video buffer to be displayed. This function

is ignored if CGA is used because CGA uses the entire

16K video buffer. The BIOS programs the CRTC Start

Address Registers in video modes 0 – 3. The BIOS

maintains the current cursor location in up to eight video

pages at 40:50h. When a new video page is selected, the

BIOS moves the cursor to the position the cursor was at

CL = Column number of upper left window corner

DH = Line number of lower right window corner

DL = Column number of lower right window corner

Output: None

Description Function 06h creates a window defined by values

specified in CH, CL, DH, and DL. It scrolls the number

of window lines upward through the window. The number

of lines is defined in AL, and the color or attribute of the

new lines is in BH. If AL is set to 00h, the window is

cleared.

Index 5