2 Apr
2015
2 Apr
'15
12:56 a.m.
On 3/30/15 12:08 AM, Simon Claessen wrote:
we have a working 4002a in our museum and I always let
it warm up with
a completely illuminated screen for a minute or 5 before clearing the
tube for the first time. that seems to do the trick.
I finished restoring the 4014's power supply this evening and as a few
of you suggested, leaving it to warm up for a few minutes seems to do
the trick; after 3-5 minutes the screen clears fully and everything
works as expected -- the stored characters stay crisp (they don't bloom
or fade) and the picture is nice and bright. So that's good! Probably
a few things are a bit out of tolerance, but I'll accept this behavior
rather than risk making things worse by trying to recalibrate it :).
Tomorrow (er, later today, I suppose) I'll actually hook it up to a
computer and throw some graphics at it...
Thanks all!
Josh
On 27-03-15 06:03, Josh Dersch wrote:
Hi all --
Picked up a Tektronix 4014-1 terminal. It's in pretty good shape, nice
and clean and it's in nearly-working condition except that the storage
behavior isn't quite right.
On power-up, write-through doesn't. (That is, characters don't get
stored to the tube.) Clearing the display via the RESET/PAGE key clears
a roughly elliptical region in the center of the display but leaves the
outer edges a mess. The cleared region stores characters properly. You
can see the overall effect here:
http://yahozna.dyndns.org/scratch/tek4014/clear.jpg
After a 2-3 minutes of warming up the area cleared by RESET/PAGE
increases. I haven't run the terminal long enough to see if it
eventually completely erases the screen (while the power supply appears
to be within tolerances, I still need to rebuild/reform it so I'm not
going to run it too long yet).
So far everything else seems to be functioning properly, the cursor
appears properly (and does not write through), input is accepted from
the keyboard, etc. I've been reading through the service manual on
Bitsavers and it describes a very in-depth alignment procedure which I'm
prepared to go through (once I've got the power supplies rebuilt) but I
thought I'd ask here if this problem rings any bells and if there's
anything I should immediately suspect or adjust. You guys know
everything :).
Thanks as always for the advice,
Josh
