Televideo 950 question (and a laugh at my expense)

Jay West jwest at classiccmp.org
Sat Apr 23 13:46:32 CDT 2005


So after I got my HP 2100 access system working, I noticed that the user 
ports (on the 12920 mux) wouldn't work on my Televideo 950. No big deal, I 
had a VT100 in the "computer room" and it worked fine. I made a mental note 
to investigate the pinouts someday, assuming the VT100 provided a signal the 
12920 mux ports were expecting.... something along those lines. Never got 
around to it.

Reorganized my "computer room" one day... and hooked everything up to the 
Televideo 950 via an ABCD switchbox. Then I brought up the 21MXE access 
system, and it suddenly because rather irritating that the TV950 wouldn't 
work on the 12920 mux ports, as during the re-org the VT100 was migrated to 
a shelf because of the switchbox. Well, now it was a pain so I spent a good 
while with a breakout box trying to figure out why an "ENTER" key on the 
TV950 would never get a "PLEASE LOG IN" prompt, but on the VT100 it always 
did. I spent hours screwing around with custom pinouts, looking at the 
control signals and figuring out what when hi/lo and when, etc. I was 
confused.

Then I noticed that big fat "LINE FEED" button on the TV950 keyboard. I hit 
enter, then linefeed, and voila! PLEASE LOG IN. This immediately struck 
home, as I know the Access 12920 mux uses an initial CR/LF to do an 
autobaud. This clearly told me that the TV950 was sending a CR, rather than 
CRLF when the enter key was pressed. Talk about egg on your face ;) I spent 
hours looking in the wrong place - vaguely analogous to forgetting to check 
that a device was plugged in. Ha. Ha.

So anyways... many terminals I've worked with support setting the 
ENTER/RETURN key to generate a CR, or a CR/LF. I can't find any such setting 
on the Televideo 950. Is it there and I'm just missing it?

Jay West 




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