I am a beginner looking for possible 8051 controllers which can be directly programmed using the RS232 serial PC port. I found a circuit which included an 89C51 which needed some additional firmware to be written on to it. I don't have a EPROM programmer so thats a no-go. Would highly appreciate suggestions.
89C51 cant be programmed directly using serial port, to the best of my knowledge you should have a programmer.
89V51RD2 is the IC by NXP which supports programming through serial port without any programmer. You need to create a hex file through your compiler and then transfer it to MCU through FlashMagic tool.
For learning purpose, FlashMagic is freely available and its easy to use.