I have the book on my shelf. It was from the original 1993 printing
I do not know which updates have happened since then, but I would be VERY hesitant to base anything on 1993 technology. We have moved from extenal to intenal memory; from 8255 to CPLD, IIC etc; from external A/D to internal A/D; from 12 clocks to 6, 4, 2 and one; from assemblet to C just to mention a few.

While there is much to be learned from older information (case in point - "the bible") I would be weary of studying older circuit design and coding practices.

When that technology was state of the art, I did it all, (external memory, 8255, external A/D etc) and while the experience I gained is indeed valuable, I do believe that the value derived versus the time spent on these issues does not justify spending the time on e.g. 8255 today where technology has progressed past that.

Erik