UDL(4) | Device Drivers Manual | UDL(4)

# NAME

`udl` — DisplayLink DL-120/DL-160 USB display devices

# SYNOPSIS

`udl* at uhub?`
`wsdisplay* at udl?`

# DESCRIPTION

The `udl` driver supports USB display devices based on the DisplayLink DL-120/DL-160 graphic chip.

# HARDWARE

The following devices should work:

Century Corp. Japan Plus One LCD-8000U
Century Corp. Japan Plus One LCD-4300U
DisplayLink USB to DVI
ForwardVideo EasyCAP008 USB to DVI
HP USB 2.0 Docking Station (FQ834)
HP USB Graphics Adapter (NL571)
IOGEAR USB 2.0 External DVI (GUC2020)
Koenig CMP-USBVGA10 and CMP-USBVGA11
Lenovo 45K5296 USB to DVI
Lenovo ThinkVision LT1421
Lilliput UM-70
Nanovision MiMo UM-710 and UM-740
Rextron VCUD60 USB to DVI
Samsung LD220
StarTech CONV-USB2DVI
Sunweit USB to DVI
Toshiba Video Dock
Unitek Y-2240 USB to DVI
VideoHome NBdock1920

# FILES

The device can process compressed data (Huffman pixel difference method) to reduce the USB payload. To generate the compressed data, the driver needs to load a Huffman table, which is stored in the following binary file:

/etc/firmware/udl_huffman

If the Huffman table can't be loaded, the driver will fall back to uncompressed mode.

# SEE ALSO

intro(4), usb(4), wscons(4), wsdisplay(4)

# HISTORY

The `udl` driver first appeared in OpenBSD 4.6.

# AUTHORS

Marcus Glocker <mglocker@openbsd.org>

May 10, 2023 | Debian