
I didn't catch your posting one year ago, but I presume you like to leave out
an extra a-latch ? (I presume you allready know there is a '573 but that couldnt
be the question, could it ? ;-)

During my student-trainee project, I discouvered a nice device, it's a PSD301  
from Waferscale Integration. In one single (44 PLCC I think it was) package
it contained: ROM, RAM, I/O lines and a programmable addressdecoder...

As far as I can recall, it can be hooked directly with a MCS-51 series uP ... 
Neat huh ? But it needs programming before assembly, so it wasn't suitable
for my project. Perhaps usefull for you (future) plans ?
