![]() ![]() Read light pen position (Does not work on VGA systems)ĪH = Status (0=not triggered, 1=triggered), BX = Pixel X, CH = Pixel Y, CX = Pixel line number for modes 0Fh-10h, DH = Character Y, DL = Character XĪL = lines to scroll (0 = clear, CH, CL, DH, DL are used),īH = Background Color and Foreground color. CX=0706h)ĪX = 0, CH = Start scan line, CL = End scan line, DH = Row, DL = Column Some video cards have 16 scan lines, 00h-0Fh. If bit 5 of CH is set, that often means "Hide cursor". So, CX=0607h is a normal underline cursor, CX=0007h is a full-block cursor. Normally a character cell has 8 scan lines, 0–7. FunctionĪL = video mode flag / CRT controller mode byte Please only add IBM/PC or other common standard functions. The list is incomplete use Ralf Brown's list for comprehensive information. In widely used UEFI 2.x systems, the INT 10H and the VBE are replaced by the UEFI GOP. In EFI 1.x systems, the INT 10H and the VESA BIOS Extensions (VBE) are replaced by the EFI UGA protocol. Such systems instead can drop into Real mode to switch the video mode, then draw to the framebuffer directly. Although most modern systems typically use device drivers that directly set the video mode, it is not feasible for hobbyist systems to have a device driver for every video card - a problem that also plagues older, unsupported systems such as Windows 98. This means that a modern operating system, which operates in Protected mode (32 bit), or Long mode (64 bit), would need to switch into real mode and back to call the BIOS - a hugely expensive operation. Setting the video mode, which is done infrequently, can be accomplished by using the BIOS, while drawing graphics on the screen in a game needs to be done quickly, so direct access to video RAM is more appropriate than making a BIOS call for every pixel.įurthermore, on a modern x86 system, BIOS calls can only be performed in Real mode, or Virtual 8086 mode. INT 10h is fairly slow, so many programs bypass this BIOS routine and access the display hardware directly. To use this call, load AH with the number of the desired subfunction, load other required parameters in other registers, and make the call. Such services include setting the video mode, character and string output, and graphics primitives (reading and writing pixels in graphics mode). ![]() The BIOS typically sets up a real mode interrupt handler at this vector that provides video services. INT 10h, INT 10H or INT 16 is shorthand for BIOS interrupt call 10 hex, the 17th interrupt vector in an x86-based computer system. ( June 2015) ( Learn how and when to remove this template message) Please help to improve this article by introducing more precise citations. ![]() This article includes a list of general references, but it lacks sufficient corresponding inline citations. ![]()
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