1.\" $NetBSD: isv.4,v 1.7 2014/03/18 18:20:39 riastradh Exp $ 2.\" 3.\" Copyright (c) 2008 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD 7.\" Foundation by David Young. 8.\" 9.\" Redistribution and use in source and binary forms, with or 10.\" without modification, are permitted provided that the following 11.\" conditions are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above 15.\" copyright notice, this list of conditions and the following 16.\" disclaimer in the documentation and/or other materials 17.\" provided with the distribution. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29.\" POSSIBILITY OF SUCH DAMAGE. 30.\" 31.Dd April 1, 2008 32.Dt ISV 4 33.Os 34.Sh NAME 35.Nm isv 36.Nd IDEC Supervision/16 image capture board 37.Sh SYNOPSIS 38.Cd "isv0 at isa? port 0x2f0" 39.Cd "isv0 at isa? port 0x2e0" 40.Cd "isv0 at isa? port 0x3f0" 41.Cd "isv0 at isa? port 0x3e0" 42.Sh DESCRIPTION 43.Pp 44.Nm 45is a driver for the IDEC Supervision/16, an image capture board 46that plugs into a 16-bit ISA bus. 47The IDEC Supervision/16 digitizes an NTSC television signal, storing 48a 512 x 480-pixel, 8-bit grayscale image in its 256kB dynamic RAM array 49every 1/30th of a second. 50The host reads frames from the DRAM using 122881 16-bit I/O reads. 51Reading frames from the Supervision/16 is quite slow: 52after the host reads a 16-bit word from the DRAM, the Supervision/16 53state machine takes approximately 0.5 microseconds to get ready 54for the next read. 55Theoretically, a frame rate of approximately 10 frames per second 56is possible. 57.Nm 58achieves a frame rate of approximately 6 frames per second. 59.Sh SEE ALSO 60.\".Xr isvctl 8 61.Rs 62.%R Programming the Supervision/16 Image Capture Board 63.%Q IDEC 64.%D circa 1991 65.Re 66.Sh HISTORY 67The 68.Nm 69device first appeared in 70.Nx 5.0 . 71.Sh AUTHORS 72The 73.Nm 74driver was written by 75.An David Young Aq Mt dyoung@NetBSD.org . 76.Sh BUGS 77Synchronizing with the hardware and reading frames from it is very 78CPU-intensive. 79.Pp 80.Nm 81will not detect the capture board if it is not attached to an active 82video source. 83To force 84.Nx 85to detect the capture board at any time, re-scan the ISA bus using, 86e.g., 87.Ic drvctl Fl r Ar isa0 . 88