The Psion Series 3 range -- 3, 3A, 3C and 3MX -- ran SIBO, later renamed EPOC, later renamed EPOC16, a multitasking GUI OS written for 8086.
SIBO = SIxteen Bit Organizer. Not OS.
https://en.wikipedia.org/wiki/Psion_Organiser#Subsequent_han...
The Psion 5 range ran the later and largely unrelated EPOC32, a native ARM OS written in C++ which later became Symbian.
But SIBO did not become Symbian. EPOC 5, later EPOS32, did.
There was even more renaming than I realised.
The Psion Series 3 range -- 3, 3A, 3C and 3MX -- ran SIBO, later renamed EPOC, later renamed EPOC16, a multitasking GUI OS written for 8086.
SIBO = SIxteen Bit Organizer. Not OS.
https://en.wikipedia.org/wiki/Psion_Organiser#Subsequent_han...
The Psion 5 range ran the later and largely unrelated EPOC32, a native ARM OS written in C++ which later became Symbian.
But SIBO did not become Symbian. EPOC 5, later EPOS32, did.
There was even more renaming than I realised.