It must have been in the eighties when we first bought a computer, of sorts. It was a word processor and it was marvellous once we worked out how to drive it. It was quite a struggle. I seem to recall we almost gave up. R's computer course from a few years earlier, which involved sticking holes into paper cards or something like that, did not seem to be particularly useful. We continued to use it into the nineties when we bought our first proper computer. It has a floppy disk for storage and one with some instructions that I immediately erased when I read 'insert the disk and select format'.
Essentially you wrote a letter or whatever on the machine, edited it until you were satisfied, and then printed it out. It even had a built in spell checker. It could be used as a conventional electric typewriter too I think. One wonderful thing about it, it was designed in times before a pop up would say, 'It looks like you are writing a letter...'. There was little to surprise you in its operation once you learnt how it worked.
While I know little about operating systems, would it have used DOS?
Here are some pictures from http://brightbit.blogspot.com/ who found one in a office storage cupboard and fired it up.