scon(1)

NAME

scon - controls screen modes for pcvt video driver

SYNOPSIS

scon [-a] [-c screenno] [-d device] [-f  on|off]  [-h]  [-H]
[-l] [-m] [-v]
     [-V] [-s lines]
scon [-v] [-d device] -p entry,red,green,blue
scon [-v] [-d device] -p default
scon [-v] [-d device] -p list
scon [-v] -t timeout
scon [-v] -1 | -8

DESCRIPTION

The scon utility controls several aspects of the runtime be

haviour of the
pcvt vt220 driver.

The options are as follows:

-a Returns a string describing the video adaptor found

by pcvt, the

string returned could be MDA, HGC, CGA, EGA, VGA or

UNKNOWN.

-c Specify the screen number the current (displayed)

screen should

be switched to.

-d Specify the device filename (i.e., /dev/ttyv2) fur

ther operations

specified on the command line should be applied to.

-f Some programs which silently assume 24 lines when

they run on a

VT220 show incorrect behaviour when the terminal has

really 25
lines. To support full VT220 behaviour, it is pos

sible to force
pcvt to select only 24 lines when it is running in

25-lines pure
VT mode and/or in 28-lines HP-mode. The -f option

requires one
additional parameter, the string 'on' or 'off' to

switch this
mode for a virtual screen on or off respectively.

This mode has
no effect if any other vertical resolutions are se

lected than the
two above mentioned.

-h Prints a usage/help text.

-l Lists the current configuration of runtime change

able options and

fixed parameters (such as the type of the adaptor,

and in case of
a VGA adaptor, the Manufacturer, Chipset and 132

column support)
of the output portion of the pcvt driver.

-m Returns a string describing the connected display

monitor type

found by pcvt, the string returned can be MONO, COL

OR or UNKNOWN.

-v Specify verbose operation of the program.

-V Switch the specified/current screen into a pure

VT220 mode with

out recognizing any HP escape sequences and without

displaying
function key labels.

-H Switch the specified/current screen into a mixed

HP/VT220 mode.

That is, that in addition to the full VT220 emula

tion, the HP
function key labels and the escape sequences for

handling the
labels are available to the user.

-s Specify the number of character lines on the screen.

Possible

parameters are 25, 28, 35, 40, 43 or 50. To use all

this screen
sizes, the fonts required for proper operation of a

desired size
have to be downloaded to the EGA/VGA font ram. This

option is
available only for EGA and VGA boards.

-p Modify VGA palette (DAC). The -p is mutually exclu

sive with -s,

-H, and -V. Naturally, option -p is available only

for VGA
boards. Three flavors are available.

If used with argument ``default'', this flag will

restore the
default palette (as installed by VGA ROM BIOS after

hardware
reset).

If used with argument ``list'', the current VGA DAC

palette
entries are listed. Each entry contains the table

index, values
for red, green, and blue, and if there is a known

name for this
entry, the color name. Trailing empty table slots

(RGB values
all zero) are omitted.

Otherwise, four comma-separated arguments are ex

pected. The
first denotes the number of palette entry to be mod

ified. This
may be either a number between 0 and 255, or the

usual name of an
associated color (case-insensitive). The following

values for
red, green and blue are restricted to 0 through 63

due to VGA DAC
conventions. Note that the first delimiter within

such an argument may be a colon ``:'' instead of a comma ``,''

for better
readability, but this violates common command argu

ment conventions. Multiple -p options may be specified if un

ambiguous.

-t Specifying -t will activate the screen saver. The

behaviour

depends on timeout: if timeout is given as 0, the

screen saver is
turned off. Otherwise, timeout is taken as a number

of seconds
to wait until activating the screen saver. NOTE:

the -t option
is only available if screen saver support has been

compiled into
the driver!

-1 Sets 132 columns mode (only available on VGA adap

tors).

-8 Sets 80 columns mode.

When switching between HP and VT mode, when switching the

force 24 lines
mode on and off, or when switching between 80 and 132

columns operation,
the screen is cleared, the scrolling region is reset and the

cursor is
placed in the home position.

EXAMPLES

The command ``scon -H -s 28'' places the current screen into

HP mode and
sets the screen size to 28x80.

Invoking ``scon -p lightgray,0,15,0 -p 0:45,45,45'' will re

sult in green
on gray output for normal text. Note that normal text color

is light
gray, and not white as one might expect.

SEE ALSO

cursor(1), loadfont(1), pcvt(4)

BUGS

the -c and -d options collide somehow, this will change in a

future
release.

BSD March 27, 2000

BSD