JDM type programmer problem...

[ardhuru]

Its constantly applying the +5 and ground, so once I have code in there that uses the internal oscilator it begins to run the code BEFORE the high voltage reaches the MCLR pin to enter programming mode.

While this is true, my parallel port based EPIC compatible has only 4 wires of ICSP (Gnd, Vpp, clock and data). So, when you connect it to a pic on a breadboard, the pic is constantly getting +5 volts from the target supply and the programmer has no way of controlling it. And yet, even with the internal osc. and MCLR disabled, a 12F6XX has no problems getting programmed over and over again.

I wonder how this can be explained?

Regards,

Anand

[mvs_sarma]

[QUOTE=ardhuru; While this is true, my parallel port based EPIC compatible has only 4 wires of ICSP (Gnd, Vpp, clock and data). So, when you connect it to a pic on a breadboard, the pic is constantly getting +5 volts from the target supply and the programmer has no way of controlling it. And yet, even with the internal osc. and MCLR disabled, a 12F6XX has no problems getting programmed over and over again.

I wonder how this can be explained?

Regards,

Anand[/QUOTE]

Hi Anand, EPIC and parallel port type you said. any circuit diagram for further discussion . or site where i could read a schematic please?