On 5/27/2015 12:01 PM, Edouard Forler wrote: > Actually 0040:0084 is not reliable. > > 0040:0084 is populated by the EGA/VGA bios only. All variables after > 0071 are not standardized and you cannot, generally speaking, rely on > them. You might want to re-read the PC Bible by Michael Tischer ;-) I > have an original copy available. > > Anyway, the patch is easy. I guess the value is 0 on pre-EGA machines, > as this area is zeroed at boot time. Which is consistent with the one > line display if I read your code correctly. Detecting the video card > before EGA/VGA is not simple. You need to make some tests. Again, the PC > Bible provides an example of routine to do so, but I think this would be > over-engineering in our case. Better keep this for a benchmark tool or > if you have a diagnostic tool in freedos and just check for 0 at 0040:0084. > I have had screen/video detection in all my software since back in the early '80s, it is relatively easy (for text modes at least) and none of my own programs has had a problem on any machine I could get my hands on, ever...
Ralf --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com ------------------------------------------------------------------------------ _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
