Subject: 4 GB RAM under FreeDOS - msg#00086

List: emulators.freedos.general

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Here are some test results which may be of interest to anyone with over 2 GB of RAM wanting to run protected mode programs. I have a P4 with 4 GB RAM which came with Windows XP (home) pre-loaded. The Windows DPMI server will not allow an application to access more than about 1.75 GB of the 4 GB installed. My task has been to find a configuration to access as much as possible of the RAM (the system requires about 750 MB or so, ). With FD HIMEM.EXE and FD EMM386.EXE: CWSDPMI won't load, but 3.24 GB is seen in real mode extended memory manager. This was the first set-up I tried and I repeat the memory dump:- Memory Type           Total      -      Used     =     Free (largest)
-------------------            -------            ---------           --------------------
Conventional             640K            74.2K            565K
Upper (XMS)                                                     64.0K
Extended (INT15)      3.24G                                0
Extended (XMS16)                                             63.9M
Extended (XMS32)                                             3.21G
Expanded (EMS)       32.1M          64K               32.0M

With FD HIMEM.EXE only:3.24 GB of XMS32 RAM shown in real mode, CWSDPMI loads OK and sees just under 2 GB but DPMIONE sees all 3.24 GB This is the setup I am using now.
With No HIMEM at all: Real Mode: Conventioal 640 K, Extended (INT15) 3.24 GB
                                       Prot. Mode: DPMIONE won't load, CWSDPMI sees 2146320384 bytes It seems that the real mode memory manager works fine, but for protected mode where DPMI is required, CWSDPMI, like the Windows DPMI server, cannot serve more than 2 GB of RAM, but DPMIONE can, so this would seem to be the best choice for a DPMI server if you have more than 2 GB of physical RAM. I hope this of interest. Best wishes, Roberto Waldteufel

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Re: DPMI with 4 GB

There is such a thing as I/O mapping, which decreases the amount of usable RAM. Usually the memory is mapped to just below 4GB. AGP GART is there for example (256MB usually), as well as other things (PCI for example). Thus, you usually see 3.3 up to 3.5GB of RAM. Bernd ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click

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Re: freedos

Whoops, ignore my last email, i sent it using another email, like a friend say: "problems exist between the chair and computer..." Hi people, uh, now i understand what jeremy said about answer email at your own time.... the first thing to say is that i think that i misunderstood something about lucho and jack really sorry guys, it wasn't my idea. sorry jack, sorry lucho. and again, sorry for this time to reply an email... well, coming back to work let's discuss some answers :) eric asked about software licenses, all those softwares are gpl (and they aren't on freedos software lists) partition saving is like norton ghost link: http://www.partition-saving.com/ license: gpl arachne is a web-browser link: http://www.cisnet.com/glennmcc/ar183gpl/ license: gpl mpxplay is like winamp (or xmms for linux) link: http://mpxplay.cjb.net/ license: gpl upx is a well know executable packer link: http://upx.sourceforge.net/ license: gpl testdisk is a Tool to check and undelete partition link: http://www.cgsecurity.org/index.html?testdisk.html license: gpl ltools make linux partitions visible to freedos link: http://www.it.fht-esslingen.de/~zimmerma/software/ltools.html license: gpl biew - binary view, a viewer of binary files with built-in editor in binary, hexadecimal and disassembler modes link: http://biew.sourceforge.net/ license: gpl syslinux, uh, no words to describe this software :) link: http://syslinux.zytor.com/ license: gpl free pascal, freepascal is a pascal compiler link: http://www.freepascal.org/ license: gpl jeremy said: >I'm just not the irc type, I prefer email (allowing me to reply in my >own time if and when I get time) uh, as i said above, now i really understand what you said... anyway, if you can, please join our mailing list, ok? :) we would be glad to have more and more fd-fans on the same place :) and even take someone to help the development of freedos... i said: >> i like arkady's optimization but i think that >> first we need to revise the kernel code before >> sending to arkady, ok for you, arkady? jeremy answered: >what sort of revisions would you like to see? for example, you fix a bug and then you can send it to arkady and he will be really happy to make this code a bit small, AFAIK :) Jim, could you and Carlos convert the section "FreeDOS on Laptops" and "FreeDOS for Gamers" in a wiki page? :) Bernd, how can i help you? i will be always here, but most times i'm in shadows, ok? if someone need some help that i can do, don't hesitate, talk to me, ok :) also, note that i have free time only on weekends, i think that most of you too... so, i don't think that it is a problem... Thanks, Geraldo ps: thanks for info, tom :) pss: The UNIX Guru's View of Sex: gawk; talk; nice; date; wine; grep; touch; unzip; strip; touch; gasp; finger; gasp; mount; fsck; more; yes; gasp; umount; make clean; make mrproper; sleep __________________________________________________________________________ Acabe com aquelas janelinhas que pulam na sua tela. AntiPop-up UOL - É grátis! http://antipopup.uol.com.br/ ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_ide95&alloc_id396&op=click

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DPMI 4 GB problem - EMM386 sees 3.24 GB but CWSDPMI sees only 2 GB

Hi everyone, Further to my last message, I tried a memory dump in 16 bit real mode running himem.exe and emm386 and found a great improvement compared to 32-bit protected mode using CWSDPMI (or DPMIONE which was even worse). A total of 3.24 GB of extended RAM is detected - here is the output:- Memory Type Total - Used = Free (largest) ------------------- ------- --------- -------------------- Conventional 640K 74.2K 565K Upper (XMS) 64.0K Extended (INT15) 3.24G 0 Extended (XMS16) 63.9M Extended (XMS32) 3.21G Expanded (EMS) 32.1M 64K 32.0M --------------------------------------------------------------------------------- FreeDOS is resident in low memory. This seems to confirm that the 4 GB of physical RAM is visible to the XMS memory manager in real mode, even if about 750MB or so is unaccounted for - it is still a vast improvement on protected mode using a DPMI server with just under 2 GB via CWSDPMI, 1.75GB via Windows XP DPMI server, or 65MB via DPMIONE. Incidentally, this usage of himem.exe and emm386.exe prevents CWDPMI from switching to 32-bit protected mode. However, with DPMIONE it is the other way around - DPMIONE needs to have himem.exe and emm386.exe to work at all. I am not sure, but if I remember correctly doesn't EMM386 use VCPI rather than DPMI? I think DPMIONE just acts as an interface between VCPI and an application requesting DPMI, which would explain why it needs to have EMM386 running to provide the VCPI services. It would be ironic if the only way to access the bulk of my 4GB RAM is to run in 16 bit mode! Thanks to all for your suggestions, Roberto

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