Lectures - how things have changed

A week of Physics lectures has set me to comparing things now with what I experienced in the 70s.

Now	Then
A strange metal box is passed round the class and each student inserts some sort of electronic key to prove his/her attendance.	There was a piece of paper outside the lecture theatre on which we signed our names.
Memory sticks are plugged into the ubiquitous computer found in every lecture theatre. Content of said stick is then projected onto one and sometimes two screens.	The more up to date lecturers had the use of an overhead projector, the majority made use of chalk and blackboard.
PowerPoint slides are the order of the day providing more or less total legibility, but any inaccuracies are indelible.	Students were at the mercy of lecturers' handwriting, though any errors made while they scrawled could be easily corrected.
All PowerPoint material seems to be accessible through computer log in; this maybe explains why many students seem to take minimal notes, if at all. The notepads in evidence or often of the computer variety.	Most students took copious notes, on paper.
Lecturers are wired for sound, so are audible throughout the lecture theatre; as a result, lecture theatres seem to fill from the back forwards.	Poor acoustics and lack of microphones ensured that it was the front rows of lecture theatres that filled first.
Film and image media are at the touch of a button as current, up to date websites and Youtube videos are accessed instantaneously, seamlessly fitting into the lecture content.	The highest tech we experienced was the occasional "slide show", with its attendant technician to operate the slide projector. The lecture theatre was dimmed, making note taking a challenge and slides that had obviously seen better days having been shown to previous generations of students were projected with varying degrees of skill ("oops that one is upside down").