Another Psion 3A owner, I bought one back in 1995 along with the matching tiny printer when i returned to college to do Mech/Electronic engineering as i thought it would be handy, it was very handy indeed as i mostly played the golf game whilst in boring lessons 😀 , seeing as the course was mostly maths and thermodynamics it saw a lot of use.
I also had a really tiny sony cassette walkman in the early 90’s which was barely bigger than a cassette box, it had dolby b, autoreverse and a direct drive motor but i can’t remember the model number, also had a pair of Koss Porta-Pro headphones to go with it – the combination was just awesome at the time and a wonder of engineering – wish i still had it for nostalgia reasons.