Quote Originally Posted by skimask View Post
I guess I'm still missing something here...

1) Do you want to build a stand-alone (no PC required at all) 24xxx programmer that would have a program already loaded into it, ready to program more 24xxx chips? Basically nothing more than a 24xxx chip copier...

2) Do you want to build you own programmer, capable of only doing 24xxx type chips with a PC connected?

3) Am I still missing a piece of the picture?
Hi - no you are not missing anything. Only thing is my poor way of asking question.

1) Yes - no PC required at all. I program the 16f84a once through PC and then it keeps programming 24xxx(s). And basically it is nothing more than a 24xxx chip copier/firmware updater.

2) That would be nice - but PonyProg can do that using olimex JDM programmer board. But need a PC with com port for that. Parallel ports are gone and com/serial port almost gone. USB is still expensive.

3) So I guess I have been able to give the picture.

This is like:
http://www.winpicprog.co.uk/pic_tutorial_i2c_board.htm

But using only 3 wires instead of 4.
Dat/CLk provides the +ve which is kept in capacitor, transistor and powers the 24cxx. Gnd is Gnd.
Three wire works for JDM program board of olimex - not my poor 16f84.

Thanks
Aftab.