Keil has a nice chip selector on their website. Use it to find a chip that has what you need, then see if you can get them where you live.

When you want help with a particular chip, as you have seen, we need to know *exactly* what chip you are referring to. The different derivatives have different SFRs so you will need to use the appropriate header file.

'89C52' alone isn't close enough...and that's most likely the source of your undefined symbols. If you had used the correct header file which had these particular SFRs defined, your code might have compiled, but it would *not* have run on an 89C52 (which doesn't have the PCA you are using).

Dennis