Hi, I had some problems with receiving mail, but reading the online list archives gives me the idea that there is a misunderstanding here...
- Tyler found a small tool, and the readme of that tool states that it is important for him (the author of the tool) to keep the tool < 0.5k size. - I checked for optimality of the binary, and found that it starts with mov ah,30 / int 21, followed directly by code to release environment from RAM (so the returned DOS version is not used). - So I asked the author of the tool why he had not optimzed away the int 21.30 call, and after a while, he remembered that he once had a program which would crash if it started with using XMS services right away. It did that on a Virtual PC system. His solution was to make the program start with int 21.30. - We had a problem with Virtual PC in emm386/himem recently, and I remembered that there was code to disable A20 between "exec" and the first int 21 call by the exec-ed program. "Conclusion": I wrote to the list, suggesting that this might be an A20 related problem, and suggesting to re-add Tom's invention, the "refuse to actually disable A20", to HIMEM (or EMM386: at least MS EMM386 locks the real A20 to on and uses the paged memory system to SIMULATE a (fast) switchable A20 for DOS), but not (as for Tom's version) as a compile time option but as a command line switch. And of course I would like some comments whether my speculations about "why use int 21.30 before XMS to avoid hangs?". Maybe that particular HIMEM or EMM386 crashed in XMS handling on that particular virtual hardware if the A20 was not enabled "explicitly" before calling the XMS handler? And of course I am interested in the state of "LOADFIX for FreeDOS". I think it once was part of FreeCOM, but 0.82pl3 does not have it compiled in? There is no separate LOADFIX listed in the LSM database either...!? Eric ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ Freedos-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/freedos-devel
