.\" Copyright (c) 1983 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)ad.4	6.1 (Berkeley) 5/15/85
.\"
.TH AD 4 "May 15, 1985"
.UC 5
.SH NAME
ad \- Data Translation A/D converter
.SH SYNOPSIS
.B "device ad0 at uba0 csr 0170400 vector adintr"
.SH DESCRIPTION
.I Ad
provides the interface to the Data Translation A/D converter.
This is
.B not
a real-time driver, but merely allows
the user process to sample the board's channels one at a time.
Each minor device selects a different A/D board.
.PP
The driver communicates to a user process by means of ioctls.
The AD_CHAN ioctl selects which channel of the board to read.
For example,
.br
.in +.5i
chan = 5;
ioctl(fd, AD_CHAN, &chan);
.in -.5i
selects channel 5.
The AD_READ ioctl actually reads the data and returns it to the user
process.
An example is
.br
.in +.5i
ioctl(fd, AD_READ, &data);
.in -.5i
.SH FILES
/dev/ad
.SH DIAGNOSTICS
None.