Tobias,

If you follow this you get rid of the problem:

Picstart Plus -> Enable Programmer
Picstart Plus -> Program/Verify
Uncheck "Calibration Memory"

Program and Verify from this window

HŠlsningar/ Regards,
Bjarne Nebelong
Manager Electrical Design
BINDOMATIC¨
mailto:bjarne.nebelong@bindomatic.se <mailto:bjarne.nebelong@bindomatic.se> 
http://www.bindomatic.com <http://www.bindomatic.com> 
+46-(0)8 709 58 46

                        -----Ursprungligt meddelande-----
                        FrŚn: Tobias [mailto:tobias@EUNET.NO]
                        Skickat:         den 25 september 1999 13:59
                        Till:   PICLIST@MITVMA.MIT.EDU
                        €mne: Still PIC12C508A programming problems..

                        Hello list,

                        I have some trouble programming a series of 12C508A
chips, I have upgraded
                        firmware on my picstart pluss from 1.20 to 2.01 as
suggested by someone on
                        this list. I am also using the latest mplab 4.12,
running win98. My
                        picstart pluss has serial nr: JIT965120923-R4

                        I think the problem is the internal osc. When I
program my chips I always
                        get an message "calibration data already programed"
at the end. Also, when
                        verifying, I always get an missmatch at 0000
(calibration data?)

                        What is the correct use of the internal osc anyway
?? Is it really
                        neccesary to calibrate the osccal register ?? Is the
internal osc.
                        different from different production series ??

                        PS! I have programed several 12c508a from other
production series with same
                        hex file without any problems..

                        Anyone have any ideas ??

                        best regards,
                        tobias