Re: I crashed one of two graphics domains
Lucky you, you had a terminal with a CRT...
As an undergraduate in the 70's I decided I wanted to do image processing. The hardware available consisted of a Univac 1106, card punch machines, a line printer the size of a Volkswagen beetle (but significantly louder than that beetle sans muffler.) The software development environment was paper pads and marker pens (to draw diagonal lines across the top of card decks.)
I chose 100 x 100 resolution (line printer was 132 characters wide) at 32 gray levels. As it was rather hard to find image data (where was Lenna when you needed her?) I wrote code to generate patterns including stripes and gradients to begin testing. (I remember one of them was based on the diamond shaped Renault emblem, easy to generate.)
To output grey levels on the paper I used the FORTRAN-IV '1H+' Hollerinth at the beginning of each line, This caused a carriage return without linefeed. Then I sent multiple overlaid lines to the printer. At each character position a 0 level would be a blank, a 1 would be a period, and so on... I think level 31 was something like overlaid {M, W, E, 3, O, S, Z, \, /, [, ], +} or some such dark sequence. This meant each line was printed 12 times using that '1H+', before a line feed occurred.
I submitted the deck of cards, and went away to lunch. When I came back, there was a note for me where the output printouts were placed. it said to immediately see the Professor in charge of the computer center. I had shredded a spool of their expensive ink ribbon and put the line printer out of action for the rest of the day - pending a service call from Univac.
What no one had told me was that the line printer had a full width ink ribbon, and that it advanced only with a line feed. So it was getting banged on 12 times in quick succession and this was happening 100 times for each image printed.
And that's how you cut an ink ribbon on a line printer...