John Payson wrote:
>
> > The osc1 pin has a 100 pf cap to ground and a 10k resistor to +5v
> > The osc2 pin is connected via a 680 ohm resistor to a bi color led for a
> > clock working indicator.<(added later).
>
> >  If I take a new pic 16c84 straight out of the box put it in the ziff
> > and
> > power up in run mode the clock oscillates,pin 4 lights the led,no
> > problem.
>
> Okay, chip is clearly in the RC mode in this case.
>
> > BLANK CHIP
> >  Now I switch to program mode on my programmer hdw.I use a simple bit of
> > code that toggles rbo when ra0 or ra1 are brought low.This code works as
> > expected in picsim no error's and compiles in mpasm no errors.Using
> > prog84.exe
> > the pic  program's verifies etc. in 62 second no problem.I choose
> > rc,powerup
> > timer,lpt1,inhx8m in the programmer software setup window no wdt no code
> > protect
> > The clock STOPS no osc2 not a blip osc1 stays high osc2 stays low.I now
> > have 4
> > 16c84 chip's that are dead.and I have only one left.Lest you think I'm
> > totally
> > stupid I did'nt use them all at once each time I have turned the board
> > inside
> > out looking for possible hdw error's shorted or overloaded pins etc.
>
> I would suggest checking the following:
>
> [1] Look at the voltage on pin 4; make sure that it really is being pulled
>     to +5.  The RC oscillator on a PIC will not run if the device is in
>     reset mode.
yes the pin 4 mclr is at +5.00 volts when I switch to run "verified yet
again just now"

> [2] Look at the voltages on both OSC-IN and OSC-OUT.  If OSC-IN is high and
>     OSC-OUT is low, try grounding OSC-IN a few times.  If OSC-OUT goes
>     opposite OSC-IN, you are programmed for the wrong clock mode.  If it
OK john thats my problem I guess when I forced osc1 low osc2 went and
stayed high (repeatable)

>     toggles high/low on each rising edge of OSC-IN, it is programmed for
>     the right clock mode.  If it just sits there, write again--something
>     is screwy.  If OSC-IN isn't high, check the VDD rail and the pullup
>     resistor.
 Well just the sort of help I was both counting on and hoped for thank
you.
Now what do I do I mean I dont have (despite looking) software that will
verify to a file
for my an589 type programmer.I mean sure the solution "picked up
lurking" would
probably be include the proper configuration data in a file or as part
of the hex
file for the programmer since it isnt doing the job correctly I
presume.But will
the prog84.exe program accept it and not overwrite it.This program is
the only one
I have tried so far that will even talk to my programmer. My system is
win95 486/66 LB/ISA
 Thanks again for the hardware insight and I suppose I can puzzle out
the rest
just knowing I had'nt fried the bug's sorta cuts the problem in half.It
was most
stressfull as I have used a lot of cmos stuff and I usually knew when I
had destroyed
a chip pretty quick. I was very carefull and yet...     Tony M.