Paul

that's difficult to answer without the schematic.

And I know it's not as good as a professionaly made eval board but you could always try it this way:
http://www.nomad.ee/micros/8052brd.jpg

It's probably a little better than a breadboard. I currently use a (similar technique) home-brew system based on
http://www.pjrc.com/tech/8051...dware.html
and it works for me, but then again, I am not a pro in the "8052 and related stuff" field. Just a hobbyist.
That being said, I have used a breadboard before, and it worked for me. Your mileage may vary. And if I were a professional I wouldn't be using a breadboard, but I am not, and if my system is not stable, then it only takes me a bit longer to figure out what was going on. As I said, I'm a hobbyist and I do not have any customers breathing down my neck (well at least not for 8052-related stuff :-)).

What I would say is: If you want to use a breadboard, you may, but if your stuff is time-critical and you have to meet a dead-line, I would design a proper PCB.

My opinion (and probably wordt about EUR 0.02).

regards
Patrick