  Terminals and Escape Sequences? (SMG) 
 The Question is:
 
Can you explain the Device Attributes (DA) exchanges (dialogues)
 
EK-VT220-RM-002
Send a Device attributes (what are you) DA to a VT220 CSI  c
VT220 to host response CSI ? 62; 1; 2; 6; 7; 8; 9 c
 
EK-VT240-HR -002
Send a Device attributes (what are you) DA to a VT240 CSI  c
VT240 to host response CSI ? 62;1
 
EK-VT320-UU-001
Send a Device attributes (what are you) DA to a VT240 CSI  c
(VT320 to Host) DA CSI ? Psc; Ps1; ... Psn c
Psc = operating level.
61 = level 1 (VT100 mode).
62,63 = level 3 (VT300 mode)  Didnt  we just see that a 62 is a VT200 series?
 
EK-VT420-UU-002
(VT420 to Host) DA CSI ? Psc; Ps1; ... Psn c
Psc = operating level.
61 = level 1 (VT100 family).
62,63,64 = level 4 (VT400 family). Didnt  we just see that a 63 is a VT300
 series?
 
EK-VT510-RM.B01
Response N.A. (VT510 to host) CSI ? 64; 1; 2; 7; 8; 9; 15; 18; 21; 44; 45; 46 c
The terminal is a class 4 device (64)   Didnt  we just see that a 64 is a
 VT400 series?
 
How can you tell one VTxxx type from each other?
 
 The Answer is :
 
  Please review the available documentation from your terminal vendor.
 
  The device levels 61 through 65 are associated with DECCRT levels 1
  through 5.  The important part of the response is the "CSI? nn;";
  OpenVMS typically (presently) ignores the bulk of the response string.
  Also note that a VT510 configured to identify itself as a VT420 will
  return device level 64, as that is appropriate for the VT420.  If
  set to identify as a VT510, the device will respond with 65.
 
  Most terminals and terminal emulators will provide configurable
  details within the terminal setup display(s).  Within the VT510
  series, enter the setup display and look for the Terminal Id to
  Host display.  The particular details, emulated terminal types,
  and such can and do vary by terminal.
 
  The OpenVMS Wizard would encourage use of SMG calls and not
  coding directly to control sequences -- even if you do not use SMG
  to control the display, you can use SMG to identify the terminal
  and/or to provide terminal-specific escape sequences and strings
  (eg: smg$get_term_data)
 
  For related details, please see the OpenVMS documentation on SMG
  and also please see the OpenVMS FAQ references to SMG and the
  available discussions of SMG here in Ask The Wizard including
  (2171), (8111), (1947), (3795), (7715), and other topics.
 
 Answer written or last revised on  17-FEB-2004 
