.Dd March 20, 1999 .Os .Dt WSDISPLAY 4 .Sh NAME .Nm wsdisplay .Nd generic display device support in wscons .Sh SYNOPSIS .Cd wsdisplay* at vga? console ? (VGA display on ISA or PCI) .Cd wsdisplay* at pcdisplay? console ? (generic PC (ISA) display) .Cd wsdisplay* at tga? console ? (DEC TGA display, alpha only) .Cd wsdisplay* at pfb? console ? (PCI framebuffer, bebox only) .Cd wsdisplay0 at ofb? console ? (Open Firmware framebuffer, macppc only) .Cd wsdisplay* at nextdisplay? console ? (NeXT display) .Cd wsdisplay0 at smg0 (VAXstation small monochrome display) .Cd options WSDISPLAY_DEFAULTSCREENS=N .Sh DESCRIPTION The .Nm driver is an abstraction layer for display devices within the .Xr wscons 4 framework. It attaches to the hardware specific display device driver and and makes it available as text terminal or graphics interface.
p A display device can have the ability to display characters on it (without help of an X server), either directly by hardware or through software putting pixel data into the display memory. Such displays are called .Dq emulating , the .Nm driver will connect a terminal emulation module and provide a tty-like software interface. In contrary, non-emulating displays can only be used by special programs like X servers.
p The logical unit of an independant contents displayed on a display (sometimes referred to as .Dq virtual terminal ) is called a .Dq screen here. If the underlying device driver supports it, multiple screens can be used on one display. (As of this writing, only the .Xr vga 4 and the .Tn VAX .Dq smg display drivers provide this ability.) Screens have different minor device numbers and separate tty instances. One screen posesses the .Dq focus , this means it is displayed on the display and its tty device will get the keyboard input. (In some cases - if no screen is set up or if a screen was just deleted - it is possible that no focus is present at all.) The focus can be switched by either special keyboard input (typically CTL-ALT-Fn) or an ioctl command issued by a user program. Screens are set up or deleted through the
a /dev/ttyEcfg control decice (preferrably using the .Xr wsconscfg 8 utility). Alternatively, the compile-time option .Cd WSDISPLAY_DEFAULTSCREENS=N will set up N screens of the display driver's default type and using the system's default terminal emulator at autoconfiguration time. .Sh FILES l -item t
a /dev/ttyE* Terminal devices (per screen). t
a /dev/ttyEcfg Control device. t
a /usr/include/dev/wscons/wsconsio.h .El .Sh BUGS The .Nm code currently limits the number of screens on one display to 8.
p The terms .Dq wscons and .Dq wsdisplay are not cleanly distinguished in the code and in manual pages.
p .Dq non-emulating display devices are not tested. .Sh SEE ALSO .Xr wscons 4 , .Xr wsconscfg 8 , .Xr wsconsctl 8 , .Xr wsloadfont 8 , .Xr vga 4 , .Xr pcdisplay 4 , .Xr tty 4