Hi Tobie,
I have seen a circuit where a 4Mhz Z80 was clocked at 10Mhz with the
addition of a 10M parallel resistor across the Xtal. I don't know how/why
this would work but am dying to find out.

                                                        John

                -----Original Message-----
                From:   Tobie Horswill [mailto:thorswil@VIDEOTRON.CA]
                Sent:   Thursday, 23 March 2000 6:26
                To:     PICLIST@MITVMA.MIT.EDU
                Subject:        Rated PIC speed ?

                Hi,

                    I've just noted that the last batch of PICs I bought
(16f84 and 16f877)
                were of the 04/P type. I've been running the F84 at 8 Mhz
and the F877 at
                20Mhz without any problems, they don't seem to be
overheating.

                    What's the physical difference between de 4Mhz and the
10 or 20Mhz
                versions and do I risk damaging them if they are run
overclocked for long
                periods ?

                    Also, has anyone been able to modify the F877's
SSPSTAT<7,6> bits also
                known as SMP and CKE  ? I'm using MPLAB 5.00 and the
simulator refuses to
                change these bits (banking is ok).

                Thanks,

                Tobie