no display name and no $DISPLAY environment variable
    while executing
"load /enadisk/commun/linux/local/ActiveTcl-8.6.11/lib/libtk8.6.so Tk"
    ("package ifneeded Tk 8.6.11" script)
    invoked from within
"package require Tk"
    (in namespace eval "::request" script line 1)
    invoked from within
"namespace eval ::request $script"
    ("::try" body line 12)
OUTPUT BUFFER:
package require Tk

proc JunkData {} {
    global nx ny dta
    
    set Lc [list A C D E F G H I K L M N P Q R S T V W Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .]
    for {set i 0} {$i < $ny} {incr i} {
        set l {}
        for {set j 0} {$j < $nx} {incr j} {
            set c [lindex $Lc [expr {int(rand()*60)}]]
            lappend l $c $c
        }
        lappend dta $l
    }

    return 
}


grid [text .t -wrap none] [scrollbar .sy -orient vertical -command yset] -sticky ewns
grid [scrollbar .sx -orient horizontal -command xset] -sticky ewns

grid rowconfigure . 0 -weight 1
grid columnconfigure . 0 -weight 1

set wx 150
set wy 30
.t configure -width $wx
.t configure -height $wy

set dta {}
set nx 5000
set ny 300

if {1} { 
    set Lc {a b c d e f g h i j k l . . . . . . . . . . . . . . . . . . . . . . . .}
    set nv [llength $Lc]
    for {set i 0} {$i < $ny} {incr i} {
	set l {}
	for {set j 0} {$j < $nx} {incr j} {
	    set c [lindex $Lc [expr {int(rand()*$nv)}]]
	    lappend l $c $c
	}
	lappend dta $l
    }

    set f [open LM.DAT w]
    puts $f [join $dta \n]
    close $f
} else {
    JunkData
}

if {0} {
    set f [open LM.DAT r]
    set dta [split [read $f] \n]
    close $f
}

.t tag configure a -foreground white -background red
.t tag configure b -foreground white -background green
.t tag configure c -foreground white -background blue
.t tag configure d -foreground white -background yellow
.t tag configure e -foreground white -background magenta
.t tag configure f -foreground white -background cyan
.t tag configure g -foreground white -background orange
.t tag configure h -foreground white -background white
.t tag configure i -foreground black -background magenta
.t tag configure j -foreground black -background cyan
.t tag configure k -foreground black -background orange
.t tag configure l -foreground black -background white
.t tag configure . -foreground white -background black

proc xset {cmd n {unit ""}} {
    global x nx wx
    switch -exact -- $cmd {
	scroll {
	    switch -exact -- $unit {
		units {
		    incr x $n
		}
		pages {
		    incr x [expr {$n*$wx}]
		}
	    }
	}
	moveto {
	    set x [expr {int($n*$nx)}]
	}
    }
    if {$x < 0} {
	set x 0
    }
    if {$x+$wx > $nx} {
	set x [expr {$nx-$wx}]
    }
    adjust
}

proc yset {cmd n {unit ""}} {
    global y ny wy
    switch -exact -- $cmd {
	scroll {
	    switch -exact -- $unit {
		units {
		    incr y $n
		}
		pages {
		    incr y [expr {$n*$wy}]
		}
	    }
	}
	moveto {
	    set y [expr {int($n*$ny)}]
	}
    }
    if {$y < 0} {
	set y 0
    }
    if {$y+$wy > $ny} {
	set y [expr {$ny-$wy}]
    }
    puts "[time {adjust}]"
}

proc adjust {} {
    global x y dta nx ny wx wy
    .t delete 1.0 end
    set R [list]
    for {set i $y} {$i < [expr {$y+$wy}]} {incr i} {
	set l [lindex $dta $i]
	lappend R {*}[lrange $l [expr {$x*2}] [expr {($x+$wx)*2-1}]] \n ""
    }
    .t insert end {*}$R
    
    .sx set [expr {double($x)/$nx}] [expr {double($x+$wx-1)/$nx}]
    .sy set [expr {double($y)/$ny}] [expr {double($y+$wy-1)/$ny}]
}

set x 0
set y 0

adjust

puts "Pour Y"
set stepx [expr {($nx-$wx)/10}]
for {set i 1} {$i <= 10} {incr i} {
    yset scroll $stepx units
}