>=20
> I think you need to be more specific about what you are writing to EEPROM=
.
> It strikes me that you should have copied the EEPROM contents to RAM, and
> accessing that. If you are using the EEPROM as your character generator,=
=20
> why
> are you writing to it on the fly?????

 The EEPROM is used to house the user defined graphics. If a user decides t=
o=20
create their own graphic, they can send it to the system using RS-232 and i=
t=20
is stored in EEPROM. However, while this is happening, the system still=20
needs to update the TV screen (keeping synchronization is the most importan=
t=20
task of the system, everything else is secondary), and therefore access the=
=20
EEPROM if there are any user defined characters on screen. The reason why I=
=20
don't use RAM is because I only have a few registers left, and I need at=20
least 64 of them.
 On the 16F688 I decided to do things differently: I will no longer allow=
=20
user defined characters to be mixed with regular characters. A line can be=
=20
defined as "is user defined" "is graphical" or "is alphanumeric". This mean=
s=20
I only need one test instead of 14 tests per line to see if the EEPROM is=
=20
being written to, which is doable.
 Also, it was never a problem for me. I just wanted people to know about=20
this undocumented difference between the 16F628 and the 16F628A. I thought=
=20
it would be useful to people.
 Greetings,
Maarten Hofman.
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