Unfortunately, the REAL teachers out there use textbooks, and textbooks often show old technology. That's probably where much of the student-interest in the i8255 orginates.
That's the crux. Why do teachers allow the use of "textbooks [that] often show old technology", I wonder. Is it because it is so much easier to teach the same as last year, than to upgrade the course?

In all the discussion, pro or con, regarding the i8255, I've not seen one line that refers to the timing requirements.
well, I have not used a 8255 for ages and thus my references to timing may be off a bit if newer faster versions have appeared. HOWEVER when there is a need to "write twice" as in this case there MUST be a timing problem.

Richard, you yourself have expressed a preference for the faster derivatives, there is no 82xx that can keep up with those. So, should we say "to use a 8255 is is ok to throttle the speed" or should we say "in order not to throttle the speed, do not use the 8255"?

If someone is stuck with an 8255 on an existing board, that is one thing, but to base a new design on an antique chip is another.

What really bothers me here is the statement here (paraphrased) "it is easy to teach the 8255" if the technology being taught is based on not what is the best to use, but what is the easiest to teach, THAT is a sad state of affairs.

Erik