1.\" $OpenBSD: udl.4,v 1.21 2017/10/17 22:47:58 schwarze Exp $ 2.\" 3.\" Copyright (c) 2009 Marcus Glocker <mglocker@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: October 17 2017 $ 18.Dt UDL 4 19.Os 20.Sh NAME 21.Nm udl 22.Nd DisplayLink DL-120 / DL-160 USB display devices 23.Sh SYNOPSIS 24.Cd "udl* at uhub?" 25.Cd "wsdisplay* at udl?" 26.Sh DESCRIPTION 27The 28.Nm 29driver supports USB display devices based on the DisplayLink DL-120 / DL-160 30graphic chip. 31.Sh HARDWARE 32The following devices should work: 33.Pp 34.Bl -tag -width Ds -offset indent -compact 35.It Century Corp. Japan Plus One LCD-8000U 36.It Century Corp. Japan Plus One LCD-4300U 37.It DisplayLink USB to DVI 38.It ForwardVideo EasyCAP008 USB to DVI 39.It HP USB 2.0 Docking Station (FQ834) 40.It HP USB Graphics Adapter (NL571) 41.It IOGEAR USB 2.0 External DVI (GUC2020) 42.It Koenig CMP-USBVGA10 and CMP-USBVGA11 43.It Lenovo 45K5296 USB to DVI 44.It Lenovo ThinkVision LT1421 45.It Lilliput UM-70 46.It Nanovision MiMo UM-710 and UM-740 47.It Rextron VCUD60 USB to DVI 48.It Samsung LD220 49.It StarTech CONV-USB2DVI 50.It Sunweit USB to DVI 51.It Unitek Y-2240 USB to DVI 52.It VideoHome NBdock1920 53.El 54.Sh FILES 55The device can process compressed data (Huffman pixel difference method) 56to reduce the USB payload. 57To generate the compressed data, 58the driver needs to load a Huffman table, 59which is stored in the following binary file: 60.Pp 61.Bl -tag -width Ds -offset indent -compact 62.It Pa /etc/firmware/udl_huffman 63.El 64.Pp 65If the Huffman table can't be loaded, the driver will fall back to 66uncompressed mode. 67.Sh SEE ALSO 68.Xr intro 4 , 69.Xr usb 4 , 70.Xr wscons 4 , 71.Xr wsdisplay 4 72.Sh HISTORY 73The 74.Nm 75driver first appeared in 76.Ox 4.6 . 77.Sh AUTHORS 78.An Marcus Glocker Aq Mt mglocker@openbsd.org 79