Dear Experts,

I used to program my own master boot loader (MBR) program for booting into multiple OS. For example, holding Ctrl to boot into Win98, holding Alt to boot into Windows XP, holding Shift to boot into Ubuntu, otherwise boot into windows 7.

The code is actually very simple, use int 16h to read keyboard status, find the LBA sector number of the specified OS and use int 13h, AH=42H (extended read sector) to load the 512-bytes (or more) partition boot loader to 0000:7C00 and jump to there will do.

Now my new HP notebook BIOS does not support disabling native SATA, nor does it support int 13h, AH=42H read, thus even utility programs like partition magic doesn't work at all. Although I have the textmode driver for slipstreaming WinXP install CD. So is there a method for accessing arbituary LBA sector in real mode (making use of the textmode drivers)?

Xuancong