Interesting! Thank you for researching this. Sadly, this guy's program is just a binary. I would be curious to read it and see exactly how he did it. I would like to implement a function to test if this works so that programmers can use it when available or otherwise use polling.
The big concern here really is battery life on laptops. I learned from Game Boy programming that polling is really taxing on batteries. You can run (anecdotally) nearly 10 times as long if you use interrupts instead, because the CPU can sleep until the next event is to be processed. Having the CPU at max load trying to catch the vblank state is really expensive from a power standpoint, even if it really makes no difference from an execution speed standpoint. I suppose CPU heat might also be an issue. Why risk damaging an old CPU because you're too lazy to set up an interrupt? Anyway, this forum post has given me some things to look into. I'll report back if I find anything good. Happy Hacking, David E. McMackins II Supporting Member, Electronic Frontier Foundation (#2296972) Associate Member, Free Software Foundation (#12889) www.mcmackins.org www.delwink.com www.eff.org www.gnu.org www.fsf.org On 07/01/2018 08:05 AM, TK Chia wrote: > Hello all, > > I am also curious about this topic. I found a recent thread on VOGONS > (https://www.vogons.org/viewtopic.php?t=58445), where Scali and others > found, after some experiments, that some x86 machines do support a > vertical retrace interrupt, when the IRQ (usually IRQ 2) is properly > enabled --- but not all support it. I guess this is why many programs > tend to use the polling method. > > Thank you! > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Freedos-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-devel
