Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
The C variant has additional features: Low Voltage Detect (LVD), Oscillator Safe Guard (OSG), Readout protection. It also uses double option byte rather than the old single byte.
Some programmers can be updated but you will need to give me more info.