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From: trier@adamwest.INS.CWRU.Edu (Stephen C. Trier)
Newsgroups: comp.protocols.tcp-ip.ibmpc
Subject: Re: Questions about PCIP
Message-ID: <1991Mar22.224713.26063@usenet.ins.cwru.edu>
Date: 22 Mar 91 22:47:13 GMT
References: <1991Mar21.023034.2452@avatar.com> <9103220835.AA01350@asylum.sf.ca.us>
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In article <9103220835.AA01350@asylum.sf.ca.us> romkey@asylum.sf.ca.us writes:
>[Re: Non-small model PC/IP's]
>It's a hassle. The problems are two-fold. First, the code's not very
>clean. Second, and more importantly, converting the tasking package to
>large memory model will be a real pain, especially if you use
>Microsoft C, which requires that all the stacks be in one segment.

I am in the process of converting a PC/IP descendent for memory model
independence.  It hasn't been too difficult so far, although I have
spent a month or so working on it (15 hour workweeks, since I'm a student)
The tricks are to replace as much assembly code as possible with C and
with standard library calls, and then to set up the tasking package to
use _nmalloc to allocate its stacks within the data segment.  (You will
also have to write four versions of the tk_swtch function, one for each
memory model.)

Of course, my converted programs are crashing occasionally, and the DNS
code still doesn't seem to work right.  I think there are still some
sizeof(char *) == sizeof(int) assumptions I haven't yet found.

Oh, the other advantage I have had as I've made this conversion is that
I am converting a Stanford PC/IP derivative.  As a result, most of the
really ugly code is inside a TSR kernel that can stay small model.  I
have just had to convert the libraries.

-- 
Stephen Trier                              Case Western Reserve University
Work: trier@cwlim.ins.cwru.edu             Information Network Services
Home: sct@seldon.clv.oh.us               %% Any opinions above are my own. %%