"CP/M compatible" vs. "MS-DOS Compatible" machines?

[Chuck Guzis]

> Date: Tue, 05 Feb 2008 20:25:07 -0500
> From: Allison 

> Maufacturing no. Design yes. back then there was little if any automated
> chip design so anything to save time or transistors on the die was good.
> The redundant moves are simple example of not decoding all possible
> states. Saves transistors at a time when getting things on that much
> silicon was still hard.

My point was "documentation" of these instructions as such was 
unnecessary.  Had the documentation simply said "---", they wouldn't 
have been used, freeing the codes for later exploitation.  But once 
documented as valid moves, there's no going back.  

00H was the only *documented* no-op as such.

But it's all 20-20 hindsight.

Cheers,
Chuck