On Tue, 23 Oct 2018, ben via cctalk wrote: > The PDP 11 is nice machine, but I am looking for simpler designs > where 16K words is a valid memory size for a OS and small single user > software. Try the Modular One with an OS written in BCPL. https://www.cs.ox.ac.uk/files/3230/PRG08.pdf Although that paper suggest 32K of core. -Gordon