Note: This IBM PC BIOS API call is for DOS/Win16 personality only. Use Family API for portability.

Note: osFree Macro Library provides macros for most of functions

2022/03/13 05:41 · prokushev · 0 Comments

Int 10H, AH=08H


IBM 5150 and higher


Get character and attribute undr cursor

osFree Macro Library

Family API


AH = 08h
BH = page number


AH - attribute
AL - character


@GetChAtr 0


  • for monochrome displays, a foreground of 1 with background 0 is underlined
  • the blink bit may be reprogrammed to enable intense background colors using AX=1003h or by programming the CRT controller
  • the foreground intensity bit (3) can be programmed to switch between character sets A and B on EGA and VGA cards, thus enabling 512 simultaneous characters on screen. In this case the bit's usual function (intensity) is regularly turned off.
  • in graphics modes, only characters drawn with white foreground pixels are matched by the pattern-comparison routine
  • on the Tandy 2000, BH=FFh specifies that the current page should be used
  • because of the IBM BIOS specifications, there may exist some clone BIOSes which do not preserve SI or DI; the Novell DOS kernel preserves SI, DI, and BP before many INT 10h calls to avoid problems due to those registers not being preserved by the BIOS.
  • some IBM PC ROM BIOSes destroy BP when in graphics modes