Again, this message was inadvertently sent only to me; I'm forwarding
it to the PICLIST.

-Andy

------- Forwarded Message Follows -------
Date:          Fri, 31 Jan 1997 22:39:45 -0600 (CST)
To:            fastfwd@ix.netcom.com
From:          Todd Peterson <elab@netins.net>
Subject:       Re: 12C508 too fast partial solution?

At 01:01 PM 1/31/97 -0800, Andrew Warren wrote:

>Todd:
>
>Yes, there's someone (I forget his name now) from CCS on the list.
>
>That is, he USED to be here... I haven't seen any messages from him
>since someone posted a long list of CCS-compiler bugs to the list
>three weeks ago.

I have found two distinct problems here; the first was a CCS compiler
error; however they did graciously fix the compiler bug problem
immediatly.

The second is that, no matter what value is written to OSCCAL (the
upper 4 bits are the only ones that matter), I cannot change the speed
of the clock. Yes, my scope is perfectly calibrated; it has a 1KHz
calibration plug that shows exactly calibrated; and besides I should
see a change anyway when moving the PIC's calibration constant from 10
to 70.  My question is: do others have this working?  If you think you
do, you might not; the device does power up to a default of 70 and you
might not be really calibrating the RC value from that.  I do read the
hex file back from the programed chip every time to verify that the
last location (the cal. constant) was programmed correctly.  I get a
.8 mS high time from the output pin regardless of the cal. constant
loaded into OSCCAL.

I hate to mess with the delay loops I know work, 'cause unsolved
problems like this invariably come back to bite you.  I would actually
be happy if I could verify that someone IS actualy tuning their R/C
properly, and not just using the powerup value of 70.  Be careful, the
last location of memory reading back as your constant is not proof it
is working; you must actually watch signals on I/O pins.

-Todd