From: Joe Bloggs [JBloggs@acme.com]
Sent: Friday, June 02, 2006 6:10 PM
To: Info-VAX@Mvb.Saic.Com
Subject: Re: [VT200 and up] Defining UDK

On 2 Jun 2006 14:10:02 -0200, peter@langstoeger.at (Peter 'EPLAN'
LANGSTOEGER) wrote:

>I once had (and maybe even wrote it) a little program to make use of the
>User Definable Keys (UDK) of a VT220 be translating the definitions in a
>textfile to escape sequences sent. I had F6-F20 with three different UDK
>meanings (Shift, Control and Shift-Control) defined (in addition to the
>normal definition, which is an unchangeable escape sequence)

from DCL,  it's a bit ugly, but doable;
outtputting, <csi> + <magic esc sequence> + <hex string> + <st>

one such magic sequence was  1;1|
I'd have to dig in the closet for the VT200 programmer's booklet
to find more.  

the bits below, date from 4.7/5.x days (beginner DCL)

$  @UDK.COM  F19   "ATTACH/PARENT"

$!
$! lines not beginning with $, wrapped from prior line by nntp client
$!
$   set noon
$   key_list       =
"*F6*F7*F8*F9*F10*F11*F12*F13*F14*HELP*DO*F17*F18*F19*F20*
$   key_num_list   = "*17*18*19*20*21*23*24*25*26*28*29*31*32*33*34*
$   delimiter      = "*"
$!+                  
$! look for P1 in key list; 
$! if found in list, save index of the list position
$!-
$   i = 0
$ LOOP1:
$       x = f$element( i+1, delimiter, key_list )
$       if( x .eqs. p1  ) then goto END_LOOP1
$       if( x .eqs. delimiter  ) then goto END_LOOP1
$       i = i + 1
$       goto LOOP1
$ END_LOOP1:
$!
$   no_match = ( x .eqs. delimiter )     ! True if not found
$   if( no_match ) then write sys$output "Invalid key name; not set
... "
$   if( no_match ) then exit
$!
$   key_num = f$element( i+1, delimiter, key_num_list )
$   dcs[0,8]  = %X090   ! terminals set to 8-bit:  CSI (144)
$    st[0,8]  = %X09C   !                          ST  (156)
$!                                                           
$!  dcs[0,16] = %X05B1B ! terminals set to 7-bit:  esc-[
$!   st[0,16] = %X02A1B !                          esc-/
$!
$!  esc[0,8]        = %X01B ! 27
$!  left_brkt[0,8]  = %X05B ! 91
$!  forw_slsh[0,8]  = %X02A ! 47
$!                 
$!  dcs = esc + left_brkt  ! terminals set to 7-bit :   esc-[
$!  st  = esc + forw_slsh  !                            esc-/
$!
$   len      = f$length( p2 )
$   hex_str1 = ""
$   i        = 0
$ NEXT_I:
$   hex_str1 = hex_str1 + f$fao( "!XB",f$cvsi(0,8,f$extract( i, 1, p2
)))
$   i = i + 1
$   if( i .lt. len ) then goto NEXT_I
$   len      = f$length( p3 )
$   hex_str2 = ""
$   j        = 0
$   if( "''p3'" .eqs. "" ) then goto SET_KEY
$!
$ NEXT_J:
$   hex_str2 = hex_str2 + f$fao( "!XB",f$cvsi(0,8,f$extract( j, 1, p3
)))
$   j = j + 1
$   if( j .lt. len ) then goto NEXT_J
$!+ 
$! the "1;1" implies: clear re-def'ed keys only; don't lock against
re-def
$!-
$ SET_KEY:
$   if( "''p3'" .eqs. "" ) then ctrl_str = dcs + "1;1|" + key_num +
"/" + hex_str1 + "0D" + st
$   if( "''p3'" .nes. "" ) then ctrl_str = dcs + "1;1|" + key_num +
"/" + hex_str1 + "0D" + hex_str2 + "0D" + st
$   tab[0,8] = 9
$!
$   write sys$output tab + tab + "...setting key"           
$   write sys$output ctrl_str