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From: sandersr@ecn-pc.UUCP (Robert C Sanders)
Newsgroups: net.micro
Subject: Re: 8086 large model compiler?
Message-ID: <617@ecn-pc.UUCP>
Date: Sun, 3-Aug-86 05:18:14 EDT
Article-I.D.: ecn-pc.617
Posted: Sun Aug  3 05:18:14 1986
Date-Received: Sun, 3-Aug-86 23:54:49 EDT
References: <2794@sdcc6.ucsd.EDU>
Reply-To: sandersr@ecn-pc.UUCP (Robert C Sanders)
Distribution: na
Organization: Electrical Engineering Department , Purdue University
Lines: 57

In article <2794@sdcc6.ucsd.EDU> ix264@sdcc6.ucsd.EDU (ix264) writes:
>				....  It develops, however, that the
>Microsoft C compiler limits me to 64k of data in any program.
>That is, in words I didn't understand until yesterday, it
>produces only small or middle model code executable on the 8086. ...
>
>     Is there any way around this?  I am willing to pay for
>software, but not for a new machine.  I don't know about
>computer architecture or assembly language programming, and I
>don't want to learn (how's that for a hardened user? :-).  If
>there's no alternative to that, though, I'm willing.  What
>I hope to find would be either
>
>1. Some sort of software letting my existing compiler and
>operating system use the memory it seems to me is right in front
>of their faces (is my frustration showing?), or
>
>2. Another compiler which can produce code executable on the
>8086 using lots of memory for data, either static or dynamic or
>both, I don't care.  Ideally it would run under Xenix, but
>MS-DOS is fine.  I'd prefer C, but am willing to look at other
>languages.  Do such compilers exist, or are they impossible
>under the constraints of the 8086?
>
>                            Tim McLarnan

Are you absolutely sure about this?  I think that it DOES allow large
model data.

My experience is with Computer Innovations C86 C compiler over MS C (they
are fairly similar), but I know that all I have to do is change the 
default #defines at the front of my code, and I can increase the stack/heap
up to the limits of memory (they are normally set for 96K to allow for
the system() call the call up command.com and whatever program).  This
means I have to malloc() or calloc() memory for the array, but that is
no problem; I just read it in from a file.

I too have a program that utilizes a HUGE data array, and I do use all
476K of main memory I have left after the program loads.  Remember, you
can't declare the array directly; declare a pointer instead, and calloc
the memory required -- MS C should also have a function the tests whether
there is any memory left, and return how much like CII C86 does.

I even created an OBJ file that I link in front of the program that resets
all of CI-C86 default values to use all of the rest of the memory -- it
just asks for FFFF segments (I even included an option in my "cc" executive
for the various-passes-of-the-compiler/MASM/LINK, -H, for "huge" model that
just links the OBJs in order).

I think MS C can do this too; but if not, I *KNOW* CII C86 does.

-- 
Continuing Engineering Education Telecommunications
Purdue University 		...!ihnp4!pur-ee!pc-ecn!sandersr

Let's make like a BSD process, and go FORK-OFF !!	-- bob
(and "make" a few children while we're at it ...)