Any Dos Memory limitations

[jam92102]

Does dos have  limit of amount of ram it will recongize and use.  Like if I have 500 MG of ram in my mame dos machiene is it going be able to use it or is there a cap?

[paigeoliver]

Does dos have  limit of amount of ram it will recongize and use.  Like if I have 500 MG of ram in my mame dos machiene is it going be able to use it or is there a cap?

Um, regardless of any memory limitations that may or may not exist with DOS, I can promise you that DOS Mame is not going to be able to use 512 MB of RAM. Dos with Mame running uses about 8-10 MB of ram, plus the unzipped size of the ROM.

[Lilwolf]

If your mame.exe is only 10mg or so...

It will take about 30mg of ram to run...

If your executable is 26mg... It will only need about 2 - 3mg.

The small file is compressed.  The ENTIRE compressed file needs to be loaded into memory to load each module.

If you run the uncompressed executable... Then you only load the modules the game itself needs.  

[Gideon]

Heh.  I didn't know computer components were being measured in milligrams these days...

Good advice, though.  Thanks!  But, what about the original question?  I can't answer it very well, but I am fairly certain that memory limitations do not inherently exist in operating systems.  Rather, the size of the memory address table of the CPU dictates how much RAM may be utilized.  Please correct me if I'm wrong.

[JoeB]

Lets put it this way..

Windows 95, which is more advanced than DOS, will actually run slower if you give it more than 256MB of RAM (or was it 128.. been a while).

so don't waste giving your PC more than 128MB of RAM if you run plain DOS.

[Chris]

DOS will only use 256MB of RAM maximum.  Up through DOS 6, you could only get that far if you used QEMM or 386Max as your memory manager, but I think the DOS with Win95 and 98 will use all 256.

Joe: Window 95 and (I believe) 98 have efficiency trouble with more than 256MB of RAM.  I think it may have been fixed in Win98 SE.

--Chris

[Howard_Casto]

The thing about ram and the reason too much can be a bad thing:

Every os handles memory differently.... it has different sub-routines and functions written to acess and write to the memory.  Every os has a different "sweet spot"  i.e. an amount of memory that was used as a base when the functions were written.  Generally these functions are written to handle far more than the base, BUT some of these functions are unoptimized to the point that when there is a butt-load of ram, say 10 times more than the base, your processor gets bogged down going through all these memory functions to the point that the ram is fine, but the processor is so bogged down with requests that the system actually performs slower.  

Not only that but as older dos programs aren't expecting to see a lot of ram, they might not even utilize the extra memory.  Remember, back in the day programs had to be small, and thus programmers cut out anything that wasn't necessary.  

What I've written isn't black and white fact, it's just genral theory based on the way operating systems work and the way programmers think.


I hope that makes sense.  

Long story short:  I you have more than 64 megs of ram you should be using a modern os..... I don't care about the excuses, dos is only good for crappy hardware.  If you don't like windows, use a stripped down version of linux, but regardless, dos is just too old to handle newer machines well.
 

[jam92102]

Well I really like arcadeos and I thought dos would be the easiest to setup but the machiene I'm planning on buying is a 1.4ghz with 512mb.  I don't want it to look like windows is running at all.  So is dos on this machiene going to be able to handle all or most mame games or am I going to have to go with xp and then hide it somehow?  Thanks for all the replies.  I really appreciate it

[Lilwolf]

btw... anyone test dr-dos?

I used to like it a LOT better then MS dos... back when I..well... used dos.

If you need more memory for some games... and you want a command line... hows the svgalib / linux version of mame these days?