Re: Reading the EDID block for x86 machines
From: Jon Smirl <hidden>
Date: 2003-03-12 23:47:58
The system BIOS may not map the ROM into the first 1MB to copy it. It probably maps it to a high address and then plays with the X86 memory management to map a segment register to it. I am having vague recollections about doing this long ago when I worked at MS. I seem to recall there is a real mode instruction that will force a register like ES to point to a high mode address. This is how an ancient EMM driver (remember the AboveBoard and Lotus 123?) was implemented on a 386 without special hardware. So you would map the ROM to a high address, map the segment register to it, copy to C000, restore segment register and jump to C000:3. ===== Jon Smirl jonsmirl@yahoo.com __________________________________________________ Do you Yahoo!? Yahoo! Web Hosting - establish your business online http://webhosting.yahoo.com ------------------------------------------------------- This SF.net email is sponsored by:Crypto Challenge is now open! Get cracking and register here for some mind boggling fun and the chance of winning an Apple iPod: http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0031en