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63 lines
2.8 KiB
TeX
63 lines
2.8 KiB
TeX
%
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% $Id$
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% This file is part of the FPC documentation.
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% Copyright (C) 1997, by Michael Van Canneyt
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%
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% The FPC documentation is free text; you can redistribute it and/or
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% modify it under the terms of the GNU Library General Public License as
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% published by the Free Software Foundation; either version 2 of the
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% License, or (at your option) any later version.
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%
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% The FPC Documentation is distributed in the hope that it will be useful,
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% but WITHOUT ANY WARRANTY; without even the implied warranty of
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% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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% Library General Public License for more details.
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%
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% You should have received a copy of the GNU Library General Public
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% License along with the FPC documentation; see the file COPYING.LIB. If not,
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% write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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% Boston, MA 02111-1307, USA.
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%
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\chapter{The EMU387 unit}
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The \file{emu387} unit was written by Pierre M\"uller for \dos. It
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sets up the coprocessor emulation for FPC under \dos. It is not necessary to
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use this unit on other OS platforms because they either simply do not run on
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a machine without coprocessor, or they provide the coprocessor emulation
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themselves.
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It shouldn't be necessary to use the function in this unit, it should be
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enough to place this unit in the \var{uses} clause of your program to
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enable the coprocessor emulation under \dos. The unit initialization
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code will try and load the coprocessor emulation code and initialize it.
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\section{Functions and procedures}
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\begin{function}{npxsetup}
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\Declaration
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procedure npxsetup(prog\_name : string);
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\Description
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\var{npxsetup} checks whether a coprocessor is found. If not, it loads the
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file \file{wmemu387.dxe} into memory and initializes the code in it.
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If the environment variable \var{387} is set to \var{N}, then the emulation
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will be loaded, even if there is a coprocessor present. If the variable
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doesn't exist, or is set to any other value, the unit will try to detect
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the presence of a coprocessor unit.
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The function searches the file \file{wmemu387.dxe} in the following way:
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\begin{enumerate}
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\item If the environment variable \var{EMU387} is set, then it is assumed
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to point at the \file{wmemu387.dxe} file.
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\item if the environment variable \var{EMU387} does not exist, then the
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function will take the path part of \var{prog\_name} and look in that
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directory for the file \file{wmemu387.dxe}.
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\end{enumerate}
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It should never be necessary to call this function, because the
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initialization code of the unit contains a call to the function with
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as an argument \var{paramstr(0)}. This means that you should deliver the
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file \var{wmemu387.dxe} together with your program.
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\Errors
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If there is an error, an error message is printed to standard error, and
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the program is halted, since any floating-point code is bound to fail anyhow.
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\end{function}
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