The first "computer" I ever used was a Wang OIS 140.

It had been installed in my father's office and he took me in to see it one day. After going through a three-week (!) course on how to use it he taught me how to use it and I probably submitted the first word-processed book report in the history of my school.

I have very fond memories of that 200lbs behemoth.

I did some co-op work terms at a spinoff company of Noma Outdoor that made development tools (CASE) for Wang, other minicomputers, workstations, and mainframes. The Wang office sharing system and terminals were exceptionally nice. The terminals were programmable in PL/I and had multi-session capability where the PL/I terminal code could manipulate data between sessions.

Now that I think of it, my high school had a Wang computer as well with dual large (much larger than 5.25") floppy disks with vertical slots in separate box/cabinet, and a 2256 looking terminal (integrated keyboard, green screen, slightly sloped sides). I mostly used the Tandy TRS-80 Model III's though.

The 2200S was the first machine I used. It had a Selectric for a printer and BASIC keywords printed on the keyboard for shortcuts. It lived in the high school marine science lab. It was fun to use.