Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!purdue!bu-cs!dartvax!eleazar.dartmouth.edu!stevel
From: stevel@eleazar.dartmouth.edu (Steve Ligett)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Getting more than 640K for DOS
Message-ID: <15187@dartvax.Dartmouth.EDU>
Date: 23 Aug 89 17:08:04 GMT
References: <1989Aug14.083008.29461@cs.dal.ca>
Reply-To: stevel@eleazar.dartmouth.edu (Steve Ligett)
Distribution: na
Organization: Dartmouth College, Hanover, NH
Lines: 25

In article <1989Aug14.083008.29461@cs.dal.ca> lane@cs.dal.ca (John Wright/Dr. Pat Lane) writes:
>A friend of mine has a package called 704K.ARC or some such which 
>puports to give you 704K of DOS accessable RAM on a monochrome or
>CGA system by somehow making real memory appear at locations A000-AFFF 
>which aren't needed unless you have a VGA/EGA.  The documentation is
>*very* vague and doesn't explain to him or me just what sort of
>physical memory situation you must have (since I assume you must
>have more than 640K *physical* RAM in your machine).  It doesn't
>really explain anything and to make a long storey short, we can't
>get the pgm working.

On old IBM PCs, not XTs, you would set switches to indicate memory size.
After replacing the ROM BIOS on my PC-1 (64k motherboard PC), I put 704K
in the PC (64K on motherboard, and 640K on an AST board), and set the
switches to 704K.  It worked just fine.  That was just normal RAM, that
responded to addresses A0000-AFFFF.  Yes, a monochrome machine.

You'll need real memory addressed at A0000-AFFFF, and a program to
initialize it, and tell the system about it, in "smarter" clones that
automatically determine memory size (up to 640K).

I kept running into that old 704K barrier when running programs! :-)

Steve Ligett       steve.ligett@dartmouth.edu or
(decvax harvard linus true)!dartvax!steve.ligett