1.\" $NetBSD: isv.4,v 1.1 2008/04/02 01:34:36 dyoung Exp $ 2.\" 3.\" Redistribution and use in source and binary forms, with or 4.\" without modification, are permitted provided that the following 5.\" conditions are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above 9.\" copyright notice, this list of conditions and the following 10.\" disclaimer in the documentation and/or other materials 11.\" provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this 13.\" software must display the following acknowledgement: 14.\" This product includes software developed by the NetBSD 15.\" Foundation, Inc. and its contributors. 16.\" 4. Neither the name of The NetBSD Foundation nor the names of 17.\" its contributors may be used to endorse or promote products 18.\" derived from this software without specific prior written 19.\" permission. 20.\" 21.Dd April 1, 2008 22.Dt isv 4 23.Os 24.Sh NAME 25.Nm isv 26.Nd IDEC Supervision/16 image capture board 27.Sh SYNOPSIS 28.Cd "isv0 at isa? port 0x2f0" 29.Cd "isv0 at isa? port 0x2e0" 30.Cd "isv0 at isa? port 0x3f0" 31.Cd "isv0 at isa? port 0x3e0" 32.Sh DESCRIPTION 33.Pp 34.Nm 35is a driver for the IDEC Supervision/16, an image capture board 36that plugs into a 16-bit ISA bus. 37The IDEC Supervision/16 digitizes an NTSC television signal, storing 38a 512 x 480-pixel, 8-bit grayscale image in its 256kB dynamic RAM array 39every 1/30th of a second. 40The host reads frames from the DRAM using 122881 16-bit I/O reads. 41Reading frames from the Supervision/16 is quite slow: 42after the host reads a 16-bit word from the DRAM, the Supervision/16 43state machine takes approximately 0.5 microseconds to get ready 44for the next read. 45Theoretically, a frame rate of approximately 10 frames per second 46is possible. 47.Nm 48achieves a frame rate of approximately 6 frames per second. 49.Pp 50.Sh SEE ALSO 51.Xr isvctl 8 52.Rs 53.%R Programming the Supervision/16 Image Capture Board 54.%Q IDEC 55.%D circa 1991 56.Re 57.Sh HISTORY 58The 59.Nm 60device first appeared in 61.Nx 5.0 . 62.Sh AUTHORS 63The 64.Nm 65driver was written by 66.An David Young Aq dyoung@NetBSD.org . 67.Sh BUGS 68.Pp 69Synchronizing with the hardware and reading frames from it is very 70CPU-intensive. 71.Pp 72.Nm 73will not detect the capture board if it is not attached to an active 74video source. 75To force 76.Nx 77to detect the capture board at any time, re-scan the ISA bus using, 78e.g., 79.Ic drvctl Fl r Ar isa0 . 80