All the questions are related to p16pro and the PIC12C509. Before any body reads on i'm just warning you that i'm just a beginner. I've got a few questions that i need answered. Can PIC's (12C509) be used in the normal manner if it is not code protected? and does the code protection just stop sombody copying it or does it mean that it can no longer be written to, so if it is not code protected can the code be overwritten or are they write once like CD's? As you can see i don't know how to 'finalise' a chip. Also can I keep the resistor between GND & MCLR even when programming the chip and if i am using an ISA card LPT will the 330pF c4 make it worse or is it safe to just leave it in anyway. I noticed that when i repeatedly read a chip (hit F6 5 times straight) that different data appears occasionally and the oscillator shows up as being different, but most of the time the actual data that i programed appears. Because of this i'm a bit scared to program too many PIC's with the fear that i may destry them all. When i hit F2 (fuses) and the MCLR pin enabled is not checked does this mean that i can no longer add data, or can i keep adding/overwriting untill code protect is chosen? Also if anybody out there has a P16PRO and an ISA LPT or a motherboard LPT can you pleas let me know the values of you Resistors and caps an the rest of the setup like do you need a 470 ohm between GND & MCLR when reading? Finally can you recommend any web sites that i can learn about PIC12C509 and PIC's in general. Can you mail any respones to sjroz1@usa.net Thanks heaps Sheldon ------------