Could please those who like to mark each badly formulated posts from apparently confused newbies, as "-1 didn't search first", try to remember their first steps in the field of electronics/microcontrollers, and be more tolerant to these questions? Could you please consider the harder way - give a short explanation, maybe also pointing out that searching would yield more details, and telling that this is not a proper way of asking in this Forum? Should subsequent questions from the same person show ignorance, OK, let him have the "-1"; but my experience is different - either the OP comes back with a properly formulated question; or, which is much more often, he simply never comes back, probably feeling too ashamed...

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Shamraz,

Welcome to 8052.com.

The evaluation ("free") version of Keil does not contain support for the (it also poses a limit on the maximum code size and, more importantly, does not allow using '51 derivatives with less than a certain amount of code memory). If you don't intend to purchase the full version - which is indeed rather expensive - you would be better off using the free C-compiler SDCC.

But, for the vast majority of '51 applications you don't need floating point support at all. It is often misused in cases where a different approach would be much better. If you post here exactly what your project is, we might give you advice on how to avoid using the floating point at all.

RAM in '51 has two forms - internal an external - and both can be accessed in several different ways. Nevertheless, all of them are accessed from C simply as variables; the trick lies in using special (non-C-standard) keywords when declaring these variables. Again, if you come with a more specific question, you will get better answer.

Jan Waclawek