phil@pepsi.amd.com (02/22/90)
I've already posted about deficiencies with regard to the NEAT
implementation of EMS 4.0 on a 286. (did I mention that in a 4 meg
system, the extended and expanded memory is allocated in chunks
of 1 megabyte?)
I figured the best solution to that issue was to go for a 386 or
386sx. NEAT still isn't! As far as I can tell, the top 384K of the
first meg is only usable for shadow RAM. In the 286 world, I am
used to that 384K being remappable to extended memory. Not so with
a 386 NEAT. If you didn't want shadow RAM for some reason, that
384K is totally unrelocatable and therefore wasted. Even if you did
want 64K or 128K of shadow RAM, you don't want it for your EMS
pageframe, so that 64K is wasted. Etc.
Are there other chip sets which are known to not be so wasteful
of RAM?
--
Phil Ngai, phil@amd.com {uunet,decwrl,ucbvax}!amdcad!phil
When guns are outlawed, only governments will have guns.phil@pepsi.amd.com (Phil Ngai) (02/23/90)
As a followup to my article, I read the documentation real carefully
and the 384K is relocatable if you only have one meg of memory
(but what 386 system only has one meg?) and not relocatable if
you have more than one meg.
--
Phil Ngai, phil@amd.com {uunet,decwrl,ucbvax}!amdcad!phil
When guns are outlawed, only governments will have guns.dhinds@portia.Stanford.EDU (David Hinds) (02/23/90)
In article <29251@amdcad.AMD.COM>, phil@pepsi.amd.com writes: > > Are there other chip sets which are known to not be so wasteful > of RAM? > The Intel/Zymos chipset for 386SX's allows full use of the memory from 640K to 1M. It supports shadow memory, but I turn that off and let QEMM handle it because I can more precisely control the areas that are shadowed that way. I have 2M memory installed, with 640K conventional and 1408K extended. The chipset wastes nothing. - David Hinds dhinds@popserver.stanford.edu
infotech@einstein.misemi (Ross Bannerman) (02/23/90)
In article <29251@amdcad.AMD.COM> phil@pepsi.amd.com () writes: >If you didn't want shadow RAM for some reason, that >384K is totally unrelocatable and therefore wasted. Even if you did >want 64K or 128K of shadow RAM, you don't want it for your EMS >pageframe, so that 64K is wasted. Etc. > >Are there other chip sets which are known to not be so wasteful >of RAM? Have you looked into software packages that can make use of the wasted 384 k between 640 and 1meg? One that comes to mind is _386 Max_ from Qualitas. Their manual says the SHADOWRAM feature will make use of the 384 k if for some reason you want to disable the shadowram. QEMM might also do this, although I'm not 100% sure. ================================================================================ Ross Bannerman | uunet!mitel!infotech Mitel Corp. +--------------------------------------------------- KANATA, Ont. Canada | Insert standard legalese here.... ================================================================LEAFS #1========
bradley.grigor@canremote.uucp (BRADLEY GRIGOR) (02/25/90)
phil@amd.com (Phil Ngai) writes:
pm>I've already posted about deficiencies with regard to the NEAT
pm>implementation of EMS 4.0 on a 286. (did I mention that in a 4 meg
pm>system, the extended and expanded memory is allocated in chunks
pm>of 1 megabyte?)
pm>I figured the best solution to that issue was to go for a 386 or
pm>386sx. NEAT still isn't! As far as I can tell, the top 384K of the
pm>first meg is only usable for shadow RAM. In the 286 world, I am
pm>used to that 384K being remappable to extended memory. Not so with
pm>a 386 NEAT. If you didn't want shadow RAM for some reason, that
pm>384K is totally unrelocatable and therefore wasted. Even if you did
pm>want 64K or 128K of shadow RAM, you don't want it for your EMS
pm>pageframe, so that 64K is wasted. Etc.
pm>Are there other chip sets which are known to not be so wasteful
pm>of RAM?
The new products from Quarterdeck (QRAM for 80286s with C&T
chipsets and QEMM-386 V5.00) are supposed to get around the
shadow RAM problem, making this memory available as expanded,
extended or "high RAM" (above 640K).
bradley.grigor@canremote.uucp : ALEX is coming to Toronto in April.
Newmarket, Ontario, Canada : TelePoker will be there - will YOU?
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