You can join them like this but not directly. You should have port A of 8255 be configured for output and then wire its outputs through a set of open collector drivers such as 74LS07. The outputs of the open collector drivers each need a pullup resistor to +5V and are then wired back to the port B of the 8255. These lines now also wire back out to the microcontroller Port 1.
You can then output from Port A at PC and input from Port B. The PC needs to make sure to write 0FFH to Port A whenever it expects input coming from the microcontroller. Likewise the microcontroller needs to keep its port 1 set to 0FFH whenever it expects data coming from 8255 port A.

I hope this helps.
Michael Karas