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DOS 4GB RAM, 0 KB FREE...huh?

September 4, 2016 at 20:59:12
Specs: DOS 7.10, 4GB
Got a real mystery here folks. Got a friend with a Dimension 8400. He has turned into into a dedicated DOS box for a project. He is running MS-DOS 7.10 on an 8 GB flash drive on the Dimension, booting as an HDD. The DOS machine has a 10 GB hard drive.

Basically, for some reason...without any programs running it hogs all the RAM. He is trying to install a Soundblaster Card but he cannot because there is no memory Free. How do we get DOS to stop hogging all the memory? What is going on here?

I've included an image for your review.

"The world is a vampire and I am the throat upon which it feeds..." - S.T. Gill

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September 5, 2016 at 17:31:49
Hope that Sound Blaster isn't PnP, since DOS didn't support PnP.

Most DOS based memory managers had trouble once you hit 32 MB of RAM. That said, check your HIMEM and EMM386 configuration.

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September 5, 2016 at 19:55:04
I am having him send me his HIMEM and EMM386 configuration files and I have asked him to verify if the sound card in PnP or not. I'll get back to you.

"The world is a vampire and I am the throat upon which it feeds..." - S.T. Gill

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September 6, 2016 at 21:23:10
According to wikipedia, 7.1 was the version that came with fat32 capable versions of windows 9x:

Those operating systems couldn't handle 4 gig of ram without special modifications so why would you think their dos incarnations could handle it? You might check this recent posting:

for an explanation of problems with 98 and 4 gig of ram.

I did set up some PCI sound cards in windows 98 dos using drivers from Gateway. So assuming your cards have dos drivers you should be able to get them set up.

Drop the ram to no more than 512 meg and it'll run much better.

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September 6, 2016 at 21:54:25
I don't think it can handle it. I was never under that illusion. Look at the screenshots I provided. I'm not trying to get 4GB atm, I'm just trying to get DOS to free the memory. It says 0kb free,

"The world is a vampire and I am the throat upon which it feeds..." - S.T. Gill

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September 7, 2016 at 00:34:49
I've never tried pure dos with anywhere near that much ram but it certainly sounds like a resource issue caused by all that ram. It may seem counter-intuitive but if I'm right removing some of the physical ram will free up usable ram.

Well, post back contents of config.sys and autoexec.bat. If there's any way to use that much ram it's those files that will need to be modified.

message edited by DAVEINCAPS

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September 7, 2016 at 00:58:11
DOS, 4GBs of RAM? Not matching.

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September 7, 2016 at 03:34:00
I aske him to send the config.sys and he never sent it. I'll tell him to switch over to 512 and see what happens.

"The world is a vampire and I am the throat upon which it feeds..." - S.T. Gill

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September 7, 2016 at 18:35:44
Like I said initially, EMM386 would likely break if your total physical memory was above 32MB, and 512MB is still 480MB over that mark.

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September 7, 2016 at 22:20:18
I'm not sure how it would react either but I've used the emm386 version that came with 98 with as much as 256 meg and it seemed to work OK--mouse driver, sound card files and mscdex for cdrom support all loaded OK.

There's other memory managers that may work better:

but I've never tried them. The OP may need to experiment to see which, if any, will work for him.

A few things turned up in this google search:

that may be helpful. I doubt there's any benefit to running dos on that much ram, unless the surplus is set up as a ramdrive. The best to hope for is to make it usable.

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September 12, 2016 at 03:39:57
DOS can handle 640 MB of RAM.
Some drivers can be loaded in the so called upper memory.
That is the memory part between 640 MB and 1G.

The thing is, you have to load drivers into the upper memory.

This can be done as follows:

Content of the config.sys file:

REM if needed, you can load EMM386.EXE here, by remove the REM infront of the DEVICE=EMM386... line
REM but EMM386.EXE itself needs memory to run

REM change driver_name1 and 2 with the names of the drivers, you need to load

Content of autoexec.bat file:

LH driver_name3.exe
LH driver_name4.exe

Where LH stands for LOADHIGH.

So whenever it's possible to load drivers into upper memory, it will be done by LH in autoexec.bat or by using DEVICEHIGH in config.sys.

Content of msdos.sys, if you're using MSDOS version 6.22 or 7.x and msdos.sys is not a binary file.


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September 13, 2016 at 22:32:44
Without any memory managers such as Himem, Emm386, etc, MS-DOS can only access 1,024 KB (1 Megabyte) of system RAM memory, while only a maximum of 640 KB (Kilobytes) of that memory will be usable for DOS programs. With an extended or expanded memory manager, DOS will be able to see more of the installed RAM memory, depending on which memory managers you have chosen. Modern DOS based memory managers will give you access to more memory, compared to memory managers from the 1990's..

I currently have FreeDOS 1.1 (a clone of MS-DOS) installed on my vintage 2007 workstation PC which has 8 gigabytes of RAM memory, SATA hard drives, and 2 AMD Opteron server processors. I multil-boot FreeDOS along with various Linux distributions. I have zero problems running FreeDOS on this computer. Naturally it cannot possibly use all my RAM memory, but it does work with no errors.

I would not be able to install any version of MS-DOS on this computer, without using modern memory managers, which are included with FreeDOS. They can also be downloaded separately.

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September 24, 2016 at 06:10:39
I'm running Win98se booted into real-mode using Bootgui=0 in msdos.sys on a Panasonic CF-52 with 4GBytes of memory. The machine itself only allows 3.4GBytes of ram to be used. On other machines with IDE drives, I use the maxphyspage when running Win98se to limit memory just below 1GByte. This works. SO- I think some of it depends on the specific computer and the HIMEM.SYS in use. I am loading the one that came with Win98se. I use Phar-Lap extended DOS, which can use all of the extended memory on the machine, 3.4GBytes. I have a SATA 512GByte drive on the CF-52 formatted as FAT-32 which dual-boots XP.

message edited by BrianS

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