Wonder if they ever got DEC to agree to support the clone hardware
I am (slowly) piecing together the 'cloning history' of pdp-11 and its software, looks like the first clone was made in 1973 (http://www.ineum.ru/m400
) followed by several 'waves' of "SM" series machines ('small machines'); f.e. SM-3 (1978) is roughly equivalent to 11/20 and SM-4 (1979) -- to 11/40.
The ms1201 and its chipset, however, are wholly original implementations of pdp-11 ISA -- they are close enough to the originals that many of DEC hardware tests apply.