Phil,

- only 64 byte RAM,
- no UART,
- different timer using (initialization, modes)
- hardware bit I2C

For more informations please download the data sheet
from Philips.

I looked short on the SX (similiar PIC12) and it seems
really terrible to translate 8051 to PIC.
Because the big architecture differences,
you must write the complete code again.

If you not use the I2C and the only reason for using
the PIC was flash programming and reducing the cost,
I suggest using the AT89C2051 (full 51 compatible).
Then you must only adapt the timer routines.


Peter