Re: You have not lived ....
No, the earlier RM380Z was an aluminium shoebox, Z80 & CP/M based. Stupidly with the bus as a ribbon cable across the top of the cards. Also stupidly only 7 bit data on printer port. We modded about a dozen for people so their Epson MX80 could do graphics printing and the upper part of the character set. The actual interface IC was all 8 bits. Sinclair was doing the Spectrum then and Acorn the BBC model. Schools could get a grant for Apple II (Why?), BBC Model B, or RM380Z. The BBC Acorn maybe had best range of "Educational SW" (mostly worthless compared to real teaching). The RM380Z had the most useful "professional" SW, such as Wordstar, SuperCalc, every programming language, databases, massive shareware etc, purely because of CP/M. I don't remember any school being daft enough to buy the computer without at least one floppy drive.
Why would anyone have bought a RM380Z for cassette only? Maybe a home computer for games, but you'd not have ever bought any Research Machine only for home gaming.
I was out of doing that stuff and designing industrial controllers before PC got past the 8088/8086. Hardly anyone used the 186. At least, with enough RAM, some PC makers supported various flavours of Unix on the 286 (Wang had a machine about twice the size of a PC that used giant cards and ran DOS or Unix (Maybe even MS Xenix).