The Spectravideo SV-328 was my first computer so I had my first encounter with home computers in the 80s.
So why go back in time to the 70s and design an NMOS/LSTTL computer?
Well, because IMO the home computer (r)evolution began in the 70s and the 70s were as challenging and thrilling as the 80s.
It was the decade that gave birth to 8-bit microprocessors: Intel 8008 (1972), Intel 8080 (1974), Motorola 6800 (1974), MOS 6502 (1975), Zilog Z80 (1976) and Intel 8085 (1977).
Well-known home computers of the 70s were (in alphabetical order) Altair 8800, Apple 1 and Apple 2, Atari 400 and Atari 800, Commodore PET, NEC PC-8000, Sharp MZ-80K and Tandy TRS-80.
CP/M was created in 1974.
Computer kits became available for computer hobbyists.
The 1970s were also the beginning of the video game era.
One of the first arcade video games from 1972 was Pong by Atari.
The first home video game console was the Magnavox Odyssey from 1972.
Atari's VCS was introduced in 1977.
Space Invaders was released by Taito in 1978.
These are lots of reasons to follow up with the computer technology of the 70s.
The two 70s computers I'm building are the reZet80 SCOUT and the reZet80 PIONEER.
The reZet80 SCOUT is a minimalistic single-board computer (SBC) equipped with a Z80 CPU, 1 KiB of RAM and 2 or 4 KiB of ROM, one input and one output port.
These ports connect to a 20-key keypad as default input and a 2-digit 7-segment display as default output.
The reZet80 PIONEER is a modular stand-alone computer system, the big sister/brother of the reZet80 SCOUT.
It can accomodate more RAM and ROM, more I/O ports and is expandable.