6 Mar
2002
6 Mar
'02
12:46 a.m.
VT55 with integrated printer
Not thermal or electrostatic
From 1977 until about 1980 we actually used the
terminals to print graphics
from bacterial growth curves. The paper exited the side of the terminal.
We usually
attached a weighted paper clamp to help pull the paper out of the
printer. The printer was placed so the paper hung down off the side of the
desk or table. The paper was initially wet and came in foil enclosed rolls.
The printer generated a spark to discolor the paper at the correct spot,
kind of a brownish printing. The paper didn't work if it was dry. Also
there was a problem with fungus growth on opened rolls of paper that weren't
used for a long time. Maybe caused by the microbiology lab environment.
Speed of the paper motion was important, nothing like looking at plots with
varied plot speed, scrunched graphs.
Picture of the internals of the printer is at
http://vt100.net/docs/vt5c-op/
Picture of the printer with the paper hanging out the side is
http://vt100.net/docs/vt55e-tm/
Mike McFadden
mmcfadden(a)cmh.edu
At 02:23 PM 3/5/02 -0800, you wrote:
--- John Chris Wren <jcwren(a)jcwren.com> wrote:
This sounds like a machine I used to work on.
PDP-8/a, two floppy
drives, a VT-50 terminal that looked like it could have been provisioned
for an internal thermal printer, and ours had a LA-36.
Yep... they sold a bunch of them. The printer inside the VT-50 case
wasn't thermal, BTW. The "1976-1977 pdp-8/a minicomputer handbook" calls
it an "electrolytic copier" under the entry for the VT-61. My memory of
working with them was that they used funky paper and there was a wet
wiper brush that moistened the paper as it exited the printer. Perhaps
it squeegeed it. I don't recall any more.