> If you mean "optional" in that there should an option added (post-1.0) to > control A20 for potentially complex machinations (e.g. directly accessing > DOS structures at a time where HMA is mapped out), then most should agree > that an A20 handler inhibit option should be on the to-do list. If you > mean "optional" in that A20 control should not be default behavior, I think > the evidence is strong the other way.
I meant the first, but also think this option should be implemented pre-1.0. The current implementation seems very simple, for example, the XMS functions to enable disable A20 usually increase/decrease a counter which must go to zero to indeed disable the gate. I didn't find such a counter in the current Emm386. So it may be very easy to disable A20 with FD-Emm386 just by calling the enable/disable XMS function pair. > On a related philosophical note, it appears that an optimization in your > posted code can perhaps cause fatal errors in VCPI clients using a 16-bit > stack on calls to the host. If true, this reinforces the idea that, while > optimizations are great for personal code, they probably aren't a good idea > for full distributions without a chance for extended user base testing as a > "burn-in" period. Deadlines are too tight right now to accept > optimizations with potential side-effects, even if they appear harmless. This may be true, but I dont know what you mean with "it appears", possibly you should be more specific. BTW, the posted code is totally unrelated to FD v1 distribution. And I have some doubts that the testing user base is indeed that "extended". > And sadly, it appears that while DOOM works in VPC and Qemu, Stargunner > remains problematic in virtual environments, though works here in real > DOS. Given that the best protected mode debugger, 386SWAT, is fatally > incompatible with my FreeDOS development machine, I'm afraid that leaves me > learning GDB usage under Qemu. And I almost certainly won't become > sufficiently proficient with it in the short amount of time left to figure > out what's going behind the scenes of Stargunner code to correct or work > around the issue. Time shall soon tell. Stargunner running as VCPI client is not totally reliable, but that is also true for MS Emm386. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
