I recall that at University a lecturer showed this briefly in the early nineties. Most of us students stared in a mixture of awe and disbelief. I didn't learn

I recall that at University a lecturer showed this briefly in the early nineties. Most of us students stared in a mixture of awe and disbelief. I didn't learn those incantation from that brief introduction and never felt the need, even though I used a 2400 baud modem (already outdated, hence cheap) then.