On Fri, Aug 02, 2002 at 08:48:53AM -0400, Olin Lathrop wrote:
> > Maybe it may be worth thinking about writing a piece of Perl that will
> > automate those conversions. Let's start generating another list:
> >
> > * Change the CBLOCK (I hope the code uses a CBLOCK!) from 0x1c to 0x20
>
> I hope it doesn't.  CBLOCK implies absolute mode, which should be scorned by
> all beings more intelligent than the average trilobyte.
>
> RAM should be allocated with the RES directive.  This would require no code
> changes in moving from the 16F84 to the 16F628, just a switch to the linker
> file for the new processor.

Olin, I promise that I will agree to disagree. I know that you are right.
I agree that you are right. But there are so many impediments to doing it
right that it's almost not worth bothering to discuss.

* The vast majority of all assembler code, and I think I can safely say all
  tutorial PIC assembler code is in absolute format.

* And through no fault of yours ;-) some of us are not Windows users. And so
  linkers are not necessarily available. Check that: gputils does have a
  linker. I will have to test it out once I figure out how it works.

Might you have a quick linker tutorial somewhere?

>
> > * Turn off the comparitors
>
> Note that this step would also not require code changes if using my
> templates at http://www.embedinc.com/pic.  The PORT module automatically
> disables comparitors and A/Ds when present.  These are enabled later only by
> code that knows about and uses them.  A few IFDEFs solve this problem for
> good.  See the QQQ_PORT.ASPIC module for the code details.
>
> > * Change the include file
>
> There should be no need to change your project include file.  I think you
> meant to say you need to change which processor-specific Microchip include
> file is referenced.

Correct.

>
> > * Change the processor in the LIST/device line
>
> This and the previous one are one line each once for the whole project.
>
> > * Update the config line.
>
> Yup, this should be inspected carefully everytime the processor is changed.
>
> All in all these changes are trivial if proper programming practice was used
> in the first place.

The problem is though that we're talking about rank novices that don't
really understand what each of these mean. I plan to put together a conversion
page. And after hearing you out, and agreeing with you, I think that it may
need two phases:

* 16F84 to 16F628 and...
* Absolute to relative.

BAJ

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