> Our experiences with that programme informed the development of Raspberry Pi 400, our all-in-one PC, whose form factor (and name) harks back to the great 8-bit and 16-bit computers – the BBC Micro, Sinclair Spectrum, and Commodore Amiga – of the 1980s and 1990s.
(emphasis mine)
So the 400 name is explicitly inspired by such systems, their next one is called the 500, and the upgrade to that is called the 500+. I'd say it's a pretty safe bet that's exactly the inspiration.
One of the main differences between the ZX Spectrum and Spectrum+ was the upgraded keyboard. The original had the famous mushy rubber keys but the Spectrum+ had an injection-moulded keyboard
Jobs was "inspired" by a visit at Xerox labs, they showed him a GUI built using Smalltalk (which they'd also invented). So naturally, he ran back to his office and invented GUI ;)
Or for third I guess lol Jobs demoed a mac gui to Gates, and apparently Gates ran strait to his Microsoft office, where he too invented gui. Jobs was very upset for years.
I think it actually was an Apple innovation, at least for {hobbyist, home, personal} computers. I did some digging and wasn't able to find anything before the Apple II+ in 1979. Please do prove me wrong, though!
And the co-creator of ARM, Sophie Wilson, still works for Broadcom - the company which bought part of the remnants of Acorn (Element 14). This is where Eben Upton worked before going off to start the Raspberry Pi foundation.
Jack Lang was involved in the Pi, having also been involved in Netchannel, the STB company which used the Acorn technology and had funding from Hermann Hauser, co-founder of Acorn.
David Braben, co-author of Elite (and author of Zarch/Lander for the Acorn Archimedes) was an early Pi supporter.
I really want to hope the name is a nod to the Amiga 500+ (which had twice the RAM of the A500 ..)