Hi, > On Oct 26, 2022, at 3:11 PM, Robert Riebisch <r...@bttr-software.de> wrote: > > Hi Jerome, > >> Without going into great details, I have made a couple programs that >> can do some (i think) neat visual tricks that require VGA support. One >> such visual trick works on nearly all REAL hardware and in DOSBox. >> However, it does not work in any other tested VM. Therefore testing for >> any VM (that is not DOSBox) and disabling the feature when appropriate >> is very useful to that program. > > Are those tricks really worth making your program more complicated? > You don't have to include any feature you can think of.
For some things, I think so. However, testing for specific VM’s isn’t always related to a trick to pull off a fancy visual effect. Sometimes, it is necessary for other reasons. A good example waiting for vertical retrace to prevent video shear in a game. In a very simple program, you could use it for timing (yes, there are much better and reliable methods). However, some virtual machines don’t emulate that function properly. With the end result in that VM as always ready to write. I think VirtualBox is one. So, a program that relies on it actually taking some time between refreshes will not function as intended. It’s just a simple example. Like I said, there are better methods for timing. Also when they are known, many limitations of specific VMs can be worked around. Features turned off by default. etc. Not really much different from turning off/on Anti-aliased fonts on early versions of windows. > Cheers, > Robert :-) Jerome _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
