AD(4)                  OpenBSD Programmer's Manual (VAX)                 AD(4)

NAME
     ad - Data Translation A/D converter

SYNOPSIS
     device ad0 at uba0 csr 0170400 vector adintr

DESCRIPTION
     The ad driver provides an interface to the Data Translation A/D convert-
     er.  This is 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.

     The driver communicates to a user process by means of ioctl(2)s. The
     AD_CHAN ioctl selects which channel of the board to read.  For example,

           chan = 5;
           ioctl(fd, AD_CHAN, &chan);

     selects channel 5.  The AD_READ ioctl(2) actually reads the data and re-
     turns it to the user process.  An example is

           ioctl(fd, AD_READ, &data);

FILES
     /dev/ad

DIAGNOSTICS
     None.

HISTORY
     The ad driver appeared in 4.1BSD.

OpenBSD 3.0                     March 27, 1991                               1
