[Karmic] eterm not really VT102 emulator

[Roland Hughes]

 let me explain what is needed so we are both on the same page.

Thankfully there is a public access OpenVMS cluster, the Deathrow cluster, on the Web, so you can actually test this yourself. OpenVMS is where all VT terminal specifications where created and released.

In an Eterm session telnet to gein.vistech.net

The user name is DEMO and the password is USER. Neither username nor password are case sensitive on OpenVMS.

There are usually quite a few users, so the machine might be a little slow. The node naming schema for the cluster came from the fact it is running on machines companies put out to die. If gein is unavailable, there is a manson node as well. manson.vistech.net.

Once logged in you will have to type SET TERM/DEV=VT102 at the system prompt (which should be DEMO$) because Eterm doesn't send back the correct device string to be identified as a 102 terminal. You can experiment with the correct string by changing whatever it is you need to change and typing SET TERM/INQ. OpenVMS will inquire from the terminal what type it is.

On a standard VT102, or any VT terminal, the top 4 keys on the numeric keypad have the symbols PF1, PF2, PF3, PF4. In EDT (one of the older editors on the platform) they are GOLD, HELP, FIND, and DELETE LINE. Attached is a screen shot of what comes up when you have the / key mapped to HELP correctly.

Your technical reference shows the following as default key mappings.

Key Pressed Normal Application
  KP_Enter ^M ESC O M
  KP_F1 ESC O P ESC O P
  KP_F2 ESC O Q ESC O Q
  KP_F3 ESC O R ESC O R
  KP_F4 ESC O S ESC O S
  XK_KP_Multiply * ESC O j
  XK_KP_Add + ESC O k
  XK_KP_Separator , ESC O l
  XK_KP_Subtract - ESC O m
  XK_KP_Decimal . ESC O n
  XK_KP_Divide / ESC O o

  On Xterm things get mapped like this by most VMS users.

 <Key>Num_Lock: string(0x1b) string("OP") \n \
 <Key>KP_Divide: string(0x1b) string("OQ") \n \
 <Key>KP_Multiply: string(0x1b) string("OR") \n \
 <Key>KP_Subtract: string(0x1b) string("OS") \n \
 <Key>KP_Add: string(0x1b) string("Ol") \n \
 <Key>KP_Enter: string(0x1b) string("OM") \n \
 <Key>KP_Decimal: string(0x1b) string("On") \n \

There is a long and somewhat detailed description on the MAN page about BIND

 bind [ modifiers ] { keysym | button } to { string | echo | menu | script } param

  Binds a keysym or a mouse button to an action. The action syntax follows the keyword to and is identical to the syntax used for menus (see above). There can be any number of modifiers (so long as the combination is reasonable) but only one keysym or button. Valid modifiers are ctrl, shift, lock, mod1 through mod5, alt, meta, and anymod (which allows any modifier). If none are given, the keypress must not have modifier keys in use or the action will not be triggered. Use anymod to allow any arbitrary modifier key to be used. The keysym can be given in text (case-sensitive) or as a hex number. buttons should be specified as button1 through button5. Also note that alt and meta will be equivalent to one or more of mod1 through mod5, as well as perhaps each other, based on your modi‐ fier settings. You can view these settings using xmodmap -pm. See also the alt_mod and meta_mod options below.

At no place in this description does it show how to override or BIND a key in keypad mode only. Most OpenVMS developers bind the keypad - key to be delete line and the keypad + to be delete char (, from the vt102 keypad). NumLock absolutely must be bound to GOLD and the / must be bound to HELP in order to use any screen oriented editor on the system.

If you are logged into the Deathrow cluster and have set your terminal time type to an actual VT type (you can check this type typing SHOW TERM), you can try editing a junk file.

DEMO$ EDIT/EDT A.A

at the * prompt you will need to type C and hit enter from the keypad to get into CHANGE mode which is screen oriented. Once you are in screen oriented mode you can test the mapping of keypad /. Just hit it and see if you get a display like the attached image. From there you can test GOLD mapping and FIND mapping.

If you need to bail out of the editor type <CTRL>-Z to get back to a * prompt and then type QUIT and hit enter from the keypad.

If you get a "quota" error message trying to edit a file, type PURGE/LOG [...] and wait for it to complete before retrying. People from other platforms simply don't understand file versioning. They leave tons of shit lying around.

Now, if one of the themes from the site happens to have magically figured out how to make this into a VT102 emulator, I will gladly download that theme and not bother you again. I haven't found any indication that any of this has been tested against the system which created VT terminals though.

I've attached a few pages from a book of mine to help communicate the information.