Try a new 16F84?

Regards

Mike Rigby-Jones

> -----Original Message-----
> From: Franz Fasching [SMTP:fasching@AUSTRIA.IBM.COM]
> Sent: Tuesday, June 01, 1999 9:03 AM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      16F84 Tait-style programmer troubles
>
>  > From:    Jeff Webster <webstej@MINDSPRING.COM>
>  > Greetings:
>  >   You don't say how you power the circuit.  I have had similar problems
>  > when using Tait-style programmers under battery power when the
> batteries
>  > get weak.  It will read the PIC fine, and erase it fine but you will
> get
>  > errors when you try to program it.
>  >
> That should be no problem; I use a stabilized lab power supply set to 13 V
> for
> Vpp, and a 7805 for getting Vdd. But as I said, the very first read to
> verify
> the very first word programmed fails with "read 3FFF, expected
> 0186".
>
> So how can I verify that either the circuit or the 16F84 is bad?
> Any hints appreciated!
> Thanks,
> Franz