.\"	$OpenBSD: npx.4,v 1.15 2007/06/20 14:11:33 jmc Exp $
.\"
.\" Copyright (c) 1993 Christopher G. Demetriou
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    must display the following acknowledgement:
.\"      This product includes software developed by Christopher G. Demetriou.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
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.Dd $Mdocdate: June 20 2007 $
.Dt NPX 4 i386
.Os
.Sh NAME
.Nm npx
.Nd Numeric Processing Extension coprocessor and emulator
.Sh SYNOPSIS
.\" XXX this is awful hackery to get it to work right... -- cgd
.Cd "npx0 at isa? port" \&"IO_NPX0\&" irq 13
.Sh DESCRIPTION
The
.Nm
driver enables the use of the system's Numeric Processing Extension
coprocessor,
if one is present.
Numeric processing extensions are present in systems with
.Tn 486DX
CPUs and in systems with
.Tn 387
or
.Tn 487SX
coprocessors.
The
.Nm
driver is required for proper system functioning regardless
of whether or not an NPX is present.
.Sh SEE ALSO
.Xr intro 4 ,
.Xr isa 4
.Sh BUGS
There are lots of them, especially on cheap motherboards.
In particular, some motherboards do not have the interrupt lines from the NPX
to the CPU wired properly.