Re the earlier thread about T89C51RD2, and DIP replacements,
I see Atmel have just posted the August iteration of the AT89C51RD2/ED2 data sheet. In June they added DIP40, now they have PDIP40 for ED2 only, and the PDIP40 shows an order code. DIP40 looks like a ceramic package, and has no order code, so may have been a 'temp qualify pathway'.
They have also hiked the fMAX to 60MHz X1 / 30MHz X2. (was 40/20) Given that 22.1184MHz (& 24MHz) are widely used Freq, stopping at 20MHz for X2 was not a great idea.
... but to keep you on your toes, T89C51RD2 EE users need the AT89C51ED2, _not_ the AT89C51RD2 (no EE)