On Fri, 9 Apr 2021, Paul Ruizendaal via TUHS wrote:
Z80 CP/M machines were still competitive in 1981-1983
(Osborne, Kaypro)
And the Aussie Microbee... Wonderful machine, and easily hacked upon.
For example, you could expand the memory by soldering several chips on top
of each other and addressing the CS* line via bank-switching.
-- Dave