>I'm just starting out and could use some help.  I've managed to stumble
>along so far and get
>some things to work, but if anyone has any tricks, suggestions, books to
>recommend, web
>sites, etc. I would very much appreciate any help.
>
>Thanks,
>Ted

Hi Ted,
I am sure that there a others on this list who are more proficient
with the '57, but for what it's work here are my observations.

1. Use Macro's for long calls and goto to set status reg bits.
   after a long call, reset the code page bits to current page.

2. ***ALWAYS*** put subroutines and addwf PCL,F code in the
   lower half of each page. A8==0 for calls
   NOT needed for goto's

3. I have found that it pays to ALWAYS inspect the *.LST output
   from the assembler to check for page crossing on tables etc.

4. Watch out for the two level stack..coming from 16c71,74 back to
   the '57 I keep tripping over this one.

5. Track the FSR bits carefully. They can easily slip away if
   you are swapping ram pages around. I keep a stack in page zero
   and save the stack pointer in global ram whenever accessing
   the other ram pages.

6. Keep reminding yourself how cheap the part is and it is really
   worth all the extra effort to make it work!




Ray Gardiner, Shepparton, Victoria 3630,  Australia,   ray@netspace.net.au