>
> add a third one after it.. only the third one is done. Is there some delay
> between consecutive writes? Thanks for any help, and for putting up with me
> (come on, you love me really).


Yes, generally you have to wait before the write is complete before starting
a second one. Also, you have to make sure there is enough voltage/current to
complete the write during that cycle. Note that the example code uses a
"SLEEP" operating with interrupt to wait, this has the advantage that the
power consumption of the rest of the chip is reduced during the write. If
you don't use the sleep, you will still need to check for the interrupt bit
(EEIF) to be set indicating that the write is finished. Usually you will
have to clear this bit manually afterwards.

Some people would also recommend reading the EEPROM after the write, to
check if the value has actually been written to it.

If your application isn't time critical, the best thing is to check for EEIF
after your write, and wait for the write to complete that way. If it is time
critical, you could postpone this wait until before you write, thereby
allowing the write to continue while the rest of your program executes.

Note that while you are writing, a read from the area you are writing to
might not return the correct value. Most PICmicros will return the correct
contents for all other memory locations though. An exception are certain
revisions of PIC16F628A (and possibly 627A and 648A), which have a bug that
will cause the write to fail in case you read the EEPROM at the same time.
Possibly there are other PICmicros that have the same problem. Of course,
this can be prevented by waiting with reading until the write is finished.

Greetings,
Maarten Hofman.
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