Hi Wiliam,

mov P0, 0x128
mov P1, 0x254

It contain many Errors:

1. port P0 has no internal pull ups.
So you should see 0x00 anytime.

2.
The internal data space goes only
from 0x00 to 0x7F and the SFR space
from 0x80 to 0xFF
So 0x128 and 0x254 out of range.

3.
The used mov syntax move the content
of one SFR to another SFR
If you want to load a value,
the syntax must be:
mov P1, #0x80
mov P2, #0xFE

Please read carefully the manual
(e.g. Phillips data book IC20)
to understand the architecture.
And the tutorial (look to the
left on this page).

Every error free programm written for
the 8051 was executed also by an 8052
without any difference.

Regards,
Peter