Real Memory vs. Virtual Memory - Programmers Heaven

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Real Memory vs. Virtual Memory

Is there an API call under win95 to get a block of memory

that is actual ram on board, and not virutal (eligible to be

paged out)? I have 64 meg and I would like to reserve

a large block, say 15 or 20 meg that will stay FIXED to

the motherboard ram (above the 1 meg line, of course),

so that my program can have instant access to any byte

within the block allocated, without fear of having to see my

hard-drive light blinking while WIN95 pages in and out

needlessly. For DOS programmer's, you know you can

run real mode with the granularity bit set on for GS, FS, and

even ES, and you can overrides to get acces to all the

ram on your motherboard without having to experience

hard drive "paging". This is very fast, but when I try this

under win95, somehow it thinks it has to go wild paging

in and out. What gives? It makes memory intensive

computations take many times longer. Using DOS4g

(that's what it is called) means you lose all the good

benefits of win95, but then you lose fixed access to

board ram with win95. How do windows programmers

solve that problem? How do you get what we mainframers

call VIRTUAL=REAL (non-pagealbe main memory)?

Thanks, Jerry Burnett [email protected]


Comments

  • You can call the MS extentions API to lock down the HD.

    While this of course, fails all writes to the HD, it also

    prevents paging to and from the HD. You can mail me for the

    code if you wish. However, it might not be useful due to

    the adverse affects on other programs. Many simply don't

    recover properly from a failed disk write.


    URL:http://acheronx.resnet.tamu.edu/home/

  • You can call the MS extentions API to lock down the HD.

    While this of course, fails all writes to the HD, it also

    prevents paging to and from the HD. You can mail me for the

    code if you wish. However, it might not be useful due to

    the adverse affects on other programs. Many simply don't

    recover properly from a failed disk write.


    URL:http://acheronx.resnet.tamu.edu/home/

  • User GlobalLock

    : Is there an API call under win95 to get a block of memory

    : that is actual ram on board, and not virutal (eligible to be

    : paged out)? I have 64 meg and I would like to reserve

    : a large block, say 15 or 20 meg that will stay FIXED to

    : the motherboard ram (above the 1 meg line, of course),

    : so that my program can have instant access to any byte

    : within the block allocated, without fear of having to see my

    : hard-drive light blinking while WIN95 pages in and out

    : needlessly. For DOS programmer's, you know you can

    : run real mode with the granularity bit set on for GS, FS, and

    : even ES, and you can overrides to get acces to all the

    : ram on your motherboard without having to experience

    : hard drive "paging". This is very fast, but when I try this

    : under win95, somehow it thinks it has to go wild paging

    : in and out. What gives? It makes memory intensive

    : computations take many times longer. Using DOS4g

    : (that's what it is called) means you lose all the good

    : benefits of win95, but then you lose fixed access to

    : board ram with win95. How do windows programmers

    : solve that problem? How do you get what we mainframers

    : call VIRTUAL=REAL (non-pagealbe main memory)?

    : Thanks, Jerry Burnett [email protected]

    :






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