Re: [Freedos-devel] Idea about Virtual PC compatibility / A20 handling
Hi! 21--2004 18:05 [EMAIL PROTECTED] (tom ehlert) wrote to Eric Auer [EMAIL PROTECTED]: Hi, Pavel Novy, author of some tiny tool which Tyler found useful, writes me some explanation for if you want to keep it tiny, then why does it start with mov ah,30h / int 21h (but does not do any- thing with the returned DOS version information)?. te the intended meaning of the above sentence escapes me. Do you mean, that you not understand this paragraph? Well, for me it too not very clear, but how I understand it: - Tyler found useful utility; - Tyler ask its author, why there used (dummy) INT21/30 at start; - author (Pavel Novy) explains, that this forces A20 line enabled and without this shown below example doesn't work. LOADFIX (should be part of every FreeDOS distro! Do we have one? te In what part of the universe did you spend the last few years ? tom, please, be slightly more polite. --- 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
Re: [Freedos-devel] Idea about Virtual PC compatibility / A20 handling
Hello Arkady, LOADFIX (should be part of every FreeDOS distro! Do we have one? te In what part of the universe did you spend the last few years ? tom, please, be slightly more polite. this WAS the polite version. tom --- 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
Re: [Freedos-devel] Idea about Virtual PC compatibility / A20 handling
tom ehlert schreef: tom, please, be slightly more polite. this WAS the polite version. tom LOL! original author meant: 'if (programmer) concerned about size of program, then why add an instruction which you don't use result of afterwards? Bernd --- 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
Re: [Freedos-devel] Idea about Virtual PC compatibility / A20 handling
Hello Bernd, LOL! original author meant: 'if (programmer) concerned about size of program, then why add an instruction which you don't use result of afterwards? That's how I understood the original author as well. But then I didn't understand why our deasr Eric broadcasts this very original insight to a few hundred subscribed experts on this list ;) tom --- 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
[Freedos-devel] Idea about Virtual PC compatibility / A20 handling
Hi, Pavel Novy, author of some tiny tool which Tyler found useful, writes me some explanation for if you want to keep it tiny, then why does it start with mov ah,30h / int 21h (but does not do any- thing with the returned DOS version information)?. He found that the following code sequence would hang in Virtual PC: (com program) Start:jmp Begin XMSControldd? Begin:mov ax,4300h int 2fh cmp al,80h jne _errexit mov ax,4310h int 2fh mov word ptr [XMSControl],bx mov word ptr [XMSControl + 2],es mov ah,00h call dword ptr [XMSControl] _errexit: mov ax,4c00h int 21h Can somebody try to reproduce? Should we add some handling to our HIMEM / EMM386 for it? I think this is A20 related, something like disable A20 on exec() and reenable it again on the first int 21 call. Which is, by the way, a very useless feature: LOADFIX (should be part of every FreeDOS distro! Do we have one? It takes care to load programs outside the first 64k) is, as far as I know, taking care of possible program might expect wraparound at 1 MB in a better way. And of course I vote - again - for some HIMEM command line option switch A20 on at HIMEM start time but refuse to switch it off later. Thanks. Thanks to Pavel for checking his archives about the background of this use int 21.30 before releasing the environment of the program (which is where it was used in the binary found by Tyler) trick. 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
Re: [Freedos-devel] Idea about Virtual PC compatibility / A20 handling
Hi, LOADFIX (should be part of every FreeDOS distro! Do we have one? LOADFIX is internal, and IIRC it is already implemented in FreeCOM. Aitor --- 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
