[geeks] VT420 ConnectivityQuestions

[Mike Meredith]

Hi!

On Mon, 2 May 2022 19:39:00 -0500, Lionel Peterson wrote:
> I researched this a while ago, but now I can't find it: can I connect
> to a VT420 terminal through the DB25 connector on the back, or do I
> have to use either of the MMJ ports?

My memory of these things is /very/ rusty but we had a few vt420s back
in the day and I don't recall using the MMJ ports but the DB25. If your
testing shows that it's not the DB25 I'd trust that first. But check
the set up.

The copy of the manual on Bitsavers
(http://bitsavers.org/pdf/dec/terminal/vt420/EK-VT420-UG-001_Installing_and_Using_The_VT420_Video_Terminal_Nov89.pdf)
hints that the 'printer' port can be used for terminal comms. Although
it doesn't show the presence of a DB-25.

Another link:
https://manx-docs.org/mirror/vt100.net/docs/vt420-uu/chapter2.html does
show the DB-25 and indicates that a "one session" connection can be
done with either RS-232 or DEC-423 (presumably the MMJs).

The link on that page has the following :-

Check the setting of the first field on the third line. This setting
selects the active connector on the Comm1 port. There are two possible
settings: Comm1=RS-232 Comm1=DEC-423

The setting should match the connector you are using. If the setting is
correct, go to the next step.

If the setting is incorrect:

Use the arrow keys to move the cursor to the field.
Press Enter until the correct setting appears.

-- 
Mike Meredith (http://zonky.org/)
 "Microsoft couldn't get a clue if it were soaked in clue pheromone in
  clue bondage gear on the clue mating grounds during clue mating season
  surrounded by horny clues." -- corrupted from a SDM sig