Re: I liked the butterfly keyboard.. @Dwarf
The VT100 with the Advanced Video Option was, I believe, the first terminal to implement smooth scroll. The AVO added quite a bit to the already considerable cost of a basic VT100 terminal.
Most VT100 compatible terminals actually implemented a VT102, which was a cost-reduced VT100 with AVO built in, but did not have the expansion slot. The VT102 was the most popular of the VT100 family, although externally almost identical to a VT100.
In the UK, the most commonly bought VT100 compatible terminal was the PT100 made by Plessey, which also looked very similar.
I actually found the VT220 (LK201) keyboard a much nicer layout than the VT100, but I was not that keen on the softer feel of the keys over the VT10x terminals, and shortly afterwards I came across IBM Model F and Model M keyboards, with the Model M being the best compromise of layout and feel IMHO.