This issue isn't ever going to go away. In pro design, we are avoiding the 8255 because its not a well behaved part under some circumstances, and as we KEEP saying it IS going obsolete as an independent chip.

I still think we NEED a chip of equivalent functionality !

But that would be repeating what we said last week, and the week before, and the week......

Use a PLD (coolrunners are nice, and fast enough I find) There are few applications where you need to dynamically reconfigure the I/O of 8052 systems, though I have done it successfully on occasion.

AVOID the 8255 for modern designs.

Steve