There is a strong pull-up for 1 internal clock cycle on the transition from a 0 to a 1 on ports 1, 2 and 3. This goes for both port operations and special function operations like TX.

After that, the pin reverts to the "normal" pullup.

If you specify a derivative, the above can be true, but, it will be untrue for some other derivatives. It mayeven be that specifying "plain vanilla old standard" will suffice for 'derivative', I can not state that with absolute certainty in all cases some that look like "plain vanilla old standard" may have a "port configuration SFR" or such.

Erik