How about a pointer to this part you suggest?

If everything else you've stated about your bit-banging example is correct, 82C55 timing wouldn't hurt it at all.

Now, where's the argument that you're trying to promulgate?

This kind of comm system design is something I'd expect to put on an hourly examination for my students, except for the fact that colleges and universities are not supposed to teach current technology. They're supposed to teach science, mathematics, literature, arts, and philosophy. If you're in a school that teaches "current" technology, then you'll wind up as the guy who picks up the 0402 resistors from the floor where the "real" engineers dropped them. The "Current" technology won't be so current by the time you graduate, and, if you haven't learned the sciences (1 year of chemistry, 2+ years of physics, statics, dynamics, fluid mechanics, thermodynamics, etc.) and math (2 years of calculus and analytic geometry, differential equations, linear algebra, number theory, an assortment of other mathematical tools) and the literary and philosophical tools that teach you how, and not necessarily what, to think, you won't be prepared for the next generation, into which you'll be inserted when you finish (one can hardly call it graduate) that school.

If you've learned the skills enabling you to read and interpret device spec's, then you can move ahead into the newer technology. However, you have to know the basics first. Knowing how to "hook up" an 805x to whatever, will get that particular job done, but knowing how to use an 82C55 or a PCA9698 and when you can use which, and why, ore even why not, will actually be useful. You won't learn that in a course that tells you to "use this and then attach that..." and so on.

That's why some people pay $10k for an associate degree in "engineering technology" while others pay $40K/year for four years to get an engineering education. After that, they go to graduate school.

RE