Xref: utzoo comp.lang.c++:6415 comp.lang.c:25823
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!ucsd!ucsdhub!hp-sdd!apollo!nelson_p
From: nelson_p@apollo.HP.COM (Peter Nelson)
Newsgroups: comp.lang.c++,comp.lang.c
Subject: Zortech "limitation"
Message-ID: <48910321.20b6d@apollo.HP.COM>
Date: 10 Feb 90 20:58:00 GMT
Sender: root@apollo.HP.COM
Distribution: usa
Organization: Hewlett-Packard Apollo Division - Chelmsford, MA
Lines: 56





  I've been using the Zortech C++, Version 2.0 compiler
  to write a CA (Cellular Automata) tool, which I've 
  discussed elesewhere on Usenet, for my PC.  I'm not
  currently taking advantage of its C++ features -- I
  thought I would do that later as an educational exercise--
  for now I'm using vanilla C. 

  But I DO need to handle large, 2-dimensional arrays
  and Zortech seems to have a problem with that.

  The problem is that my total global memory will exceed 
  64K, although I am grudgingly willing to settle for having
  no *one* array exceed that size if that would help here.

  Those who are unfortunate enough to be familiar with 80x86
  architecture are well aware of the weird, segmented addressing 
  scheme that those computers use and how this has forced compiler
  makers to create bizarre "memory models" to handle it.  Zortech
  offers two memory models (Large and Compact) which allow the 
  program to access global or static memory which may exceed 64K.
  (They don't offer a "Huge" memory model, as Microsoft does).

  But they do not apparently offer any way to access memory > 64K
  AS 2-DIMENSIONAL ARRAYS, which is the logical data structure 
  for cellular automata.   All I apparently can do with their 
  product is malloc a chunk of space and access it via pointers.
  If I wanted to do pointer arithmetic all over the place I would
  use Assembler!   Zortech C/C++ is allegedly a high-level language
  but their manual describes this as a "limitation" of their product.
  I would call it a bug. 

  I did call their Arlington office and spoke to several people
  who were unable to provide a workaround but they did suggest that
  the legendary Walter Bright, who has been known to appear in 
  the netherworld of Usenet, might have some ideas about this. 

  If anyone has some ideas on this I would appreciate it if they
  would send me email, since for the last week or so we have not been 
  getting new Usenet postings at this site. 

                                               ---Peter


  PS-  The Arlington office mentioned a Zortech BBS in Washington
       state which I dialed and got a carrier, but for some reason 
       I couldn't talk to it.  My modem *thought* it made a connection
       but nothing I typed got echoed, I didn't get any characters from
       it, and although it never hung up on me, eventually I got bored
       and hung up on it.   Comments, anyone?