Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!clyde.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!drivax!liberato From: liberato@dri.com (Jimmy Liberato) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: How to get 384K RAM back Message-ID: Date: 23 Dec 90 06:39:42 GMT References: <1755@gold.gvg.tek.com> <167@raysnec.UUCP> <9590@pasteur.Berkeley.EDU> Organization: Digital Research, Inc., Monterey Developement Center Lines: 33 In article <9590@pasteur.Berkeley.EDU> slin@campanile.berkeley.edu (Steven Lin) writes: >All motherboards manufactured by Micronics put the 384k way up at the >16M (yes, 16 Megabyte) boundary. Quarterdeck's expanded memory manager >(QEMM) will automatically recover this 384k for use as expanded memory, >provided you disable hardware shadowing. Note QEMM will shadow for you >if you want it. This is an area I would like more elaboration on. Norton's book mentions this in a diagram but does not elaborate. 1. OK, if the ram that is to be used for rom shadowing is put at the top of extended memory how is it at the same time mapped to AAAA-FFFF? 2. On advanced boards like the Micronics, if hardware shadowing is disabled isn't the equivalent amount of ram now available as extended memory? I guess this might be what was meant above when it was said that QEMM could now recover it as expanded. Even if I have no memory manager to emulate EMS it should be visible as extended. Right? 3. On a 386 is there any advantage to have shadowing be done at the motherboard instead of with a software memory manager (QEMM)? 4. Manifest, in the extended memory section, says something like: "[memory available], used from the top." What does "used from the top" mean? Does this have any relation to the 16M boundary mentioned above? Thanks for any comments! -- Jimmy Liberato liberato@dri.com ...uunet!drivax!liberato