From what I've seen, m$ is far more heavy handed than IBM ever was,
and DEC never came close to either.
Have to agree, but I think both IBM and MSFT build unnecessary
complexity into their products to forestall efforts of competitors to
duplicate their products.

On this topic I was intrigued by the new opcodes IBM introduced in
1978.

Before then, every 4-byte instruction had the form xxxxBDDD
and every 6-byte instruction had the form xxxxBDDDBDDD
where BDDD had a consistent interpretation.

The MVS/SE instructions introduced in 1978 deviated from that
format, for no particularly good reason. At the time I wondered
if that was deliberate, hoping that such a redefinition would be
tedious and expensive for 370-compatible manufacturers, like
Amdahl, to adapt to.

Was it?

James Dow Allen