Last time I saw a real “semi auto” transmission, it was in a 1971 Volkswagen Super Beetle. Had the stickshift, but no clutch. Two forward speeds; just low gear and high gear.
Used to see buses like that all the time in Dublin, back when they had Leyland Titan buses (rear entrance) and Leyland Atlanteans (front entrance); those had five-speed “semi autos” although the bus drivers would start in second gear during normal driving.
As I recall, even the manual syncro mesh gear drive could be worked by ear without a clutch
Down shift up shift listen and wait
I’m quite familiar with double-deck busses. I got a few in my Matchbox collection :)