Anyone knows how to program 8051 or 892c59 directly through the serial port?

Question

I am unaware of this method, i belive this doesn't require a programming kit.

Answer 1

Yes, its called "in system programming". most (if not all) micro venders have free software to do this. I know philips and atmel do. you need the software from the vender you are getting your micro's from because they only work with their own micro's. There is 1 catch though (at least on older micro's) there is some hardware connections that have to be made on your design. you need to be able to jumper the PSEN (I might be wrong on the exact pin) low at startup to enter the ISP mode. Philips has newer micro's that dont need that (very nice when your design is in a case and you dont want to open it up).