I am able to connect my sim900 gsm module with hyper terminal but I am not able to connect it with 89s52. Please help me to connect it.
What? You didn't notice that this thread is about "How to interface GSM module with 89s52" - and that your question on integer promotion has, aparently, nothing whatsoever to do with that topic?
yes but I don't know how to make a new topic.