Just considering its use is the stuff of night sweats: will I find the on-switch, will the page be upside down or back to front, out of focus or projected on to the roof? Will the image be too big to fit in the room or too small to decipher? And what happens if the bulb explodes?
I was never frightened by one when small, and other than on in-service afternoons of mind-numbing boredom, I do not particularly associate them with anything traumatic. The truth, I suspect, is less exciting, for although I talk a good game, muttering about being a "words man" and a "direct communicator", I avoid using these infernal machines because I am inept when it comes to technology.
Back in the early days, the Banda duplicator was fine, freshly produced sheets proving a highly effective anaesthetic to the frantically sniffing lads of my Thursday afternoon Rosla class (the generation condemned by legislation to stay on for the extra year beyond 15), but it all started to go horribly wrong shortly afterwards.
At this point, I should offer a profound, public and humble apology to those folk based in Glasgow's Dowanhill who prior to the video age loaned out cine films for use in the classroom. Stan Barstow's A Kind of Loving provided the nadir of my experiences. Furiously sweating in front of 34 fourth-years in a blacked-out classroom, I eventually succeeded in threading the film into the huge, complicated and fearsome projector.
The trouble was, it never came out again. Just after Ingrid told Vic she was pregnant, the projector started to chew up film with a noise like the cracking of walnuts. In my youthful optimism, not to say outright panic, I wrenched out the bits of film that were still accessible to the outside world, bundled them into the film can and sent it back by return of post, hoping no one would notice.
Video is less stressful, once it's up and running, but many readers will have shared the panic of being forced to channel hop frantically for the audio-visual channel. How painful to hear are the mounting roars of recognition from second-year pupils as the snowy images of Richard and Judy, Padraig Post and the guy in flairs and tank-top doing quantum physics flash across the screen like lost souls in a blizzard.
It is only fairly recently that my copy has reached The TES Scotland office by a method fractionally more automated than that involving a graphite pencil and the leg of a passing pigeon, and still I am treated by the school's computer person as a kind of favourite uncle, well meaning but sadly demented, who has to have everything explained slowly and often.
However, I am able to share this weakness with you, because it has finally been conquered. Stung into action by the blatant disbelief of my colleagues that I could have retained my credibility as a teacher without a close relationship with clingfilm graphics, I took the plunge at a recent parents' meeting. Much as an itch is camouflaged by the additional pain caused by scratching, I survived my encounter with the overhead projector because I was shocked rigid at being attached, without warning, to a radio microphone.
Now, how do I find Hibs on the Internet?