the school (and all schools in the same boat, by implication) should replace 30 +/- development boards because they use 8255s?

newer equipment might be easier to use, but (just for instance, i am brainstorming here, not a flame :) ...

* no urgent reason to replace. and old as they might be, these boards are not likely to be the dustiest equipment in an academic lab.

* the common denominator is going to be the all-Intel solution. if you want to cover the major brands, you are looking at buying a set of boards, one chip manufacturer, for each student or lab group. (and, only if you're lucky, you didn't choose Triscend as one of the chip vendors). we just had a thread not so long ago about everyone's favorite 51 variant; the list might look very different in 10 years. a non-generic vendor means non-generic upkeep. the professor might still be there in 10 years, but the vendor might have disappeared by then.

* the students will learn more on equipment that is harder to work with. Arnold S. didn't get there by lifting 5-lb. handweights.

* the students might come across legacy designs with 8255s upon graduation.

* if this is not the first time the boards have been used in this lab, the professor has probably seen many other students solve the same problem on the same boards in the past. what's he going to say if Lisa tells him "the 8052.com guys say the problem is our dusty old lab hardware, and your incompetence in continuing with it; we need to update our hardware?"

* for senior project in 1988, our group bought our own $500 ciarcia 8051 board (an 8255 design!; the digital electronics lab used 6800 trainer boards then). the price should be a lot cheaper now, but not dirt cheap, if you are buying a quantity on a college lab budget, and not if you are buying one of each of everyone's favorite variant.

* in a trainer board, you might want a buffer chip in between the students and the microcontroller. do vendor development boards buffer all I/O? (i guess it would be cheap to add this, tho, especially if the lab already has a dedicated technician.)

james