Bios Int 10H

BIOS INT 10h[pic]
IBM-PC BIOS
Most of what the BIOS does is related to Input/Output, where its function is to present the programmer with simpler, more machine and device independent I/O operations.  The IBM-PC BIOS uses software interrupts 10h ~ 1Ah, 40h to accomplish various operations. Therefore, the INT 10h ~ INT 1Ah and INT 40h instructions provide the interface to BIOS. The followingtable summarizes the BIOS services:
|10h Video display services |16h Keyboard services |
|11h Equipment determination |17h Printer services |
|12h Memory size determination |18h BASIC |
|13h Diskette and hard disk services |19h Reboot |
|14h Serial I/O services|1Ah Real time clock services |
|15h Miscellaneous services |40h Floppy Disk |


INT 10h (Video) Calls
The INT 10h instruction does several video display related functions. You can use it to initialize the video display, set the cursor size and position, read the cursor position, read or write the current display page, scroll the data in thescreen up or down, read and write characters, read and write pixels in a graphics display mode, and write strings to the display. You select the particular function to execute by passing a value in the AH register.
|BIOS Video Functions (Partial List) |
|AH |Input |Output|Description |
| |Parameters |Parameters | |
|0 |al-mode |  |Sets the video display mode. AL=00h~13h |
| | | |CGAMODES |
| | | |EGA MODES |
| | | |VGA MODES |
| | | ||
| | | |00h 40x25 16 color text1 |
| | | |07h 80x25 2 color text2 |
| | | |11h640x480 2 color graphics |
| | | | |
| | | |01h 40x25 16 color text |
| | | |0Dh320x200 16 color graphics |
| | | |12h 640x480 16 color graphics |
| | | | |
| | | |02h 80x2516 color text1 |
| | | |0Eh 640x200 16 color graphics |
| | | |13h 320x200 256 color graphics |
| | | |...