
Hey another thing you may wish to consider mentioning are the bugs in the NMOS version of the CPU.
  One of them is with regard to the buggy
IFF2->parity flag performance in the LD A,I and LD A,R instructions.  
An error can occur when an INTACK runs near these instructions: 
the parity flag will be showing 0 when it should have been 1. 
A Zilog app. note is around somewhere talking about this.
 
It's a rather nasty bug for embeddedaapps...  There are I think a few others.