On Mon, Feb 16, 2004 at 07:10:55PM -0500, Victor Faria wrote:
> 16f818 as far as I know.

Right.

> but there is the picaxe they do use an 8 pin 12f629.
> I don't know how they do it but they do it!!

I do. Pretty simple. PICAXE tokens are loaded into the data EEPROM. The
PICAXE itself is a bytecode interpreter preburned into the chip. The
interpreter reads tokens from the data EEPROM and executes them. So it
ends up being a Basic Stamp type setup using the internal data EEPROM.

My NPCI system was devised that way a few years ago. However I found the
limited amount of data EEPROM space limiting.

Of course with Wouter's ZPL technique which uses the MCLR line as a
communications channel, one can regain the use of an I/O pin with this
same technique.

It would seem that the 16F818/819 would be the best candidate as it's self
programmable and actually has enough program memory to make it worthwhile.

I believe that a F819 with a NPCI interpreter and a ZPL bootloader would
make for a interesting development system especially when using the internal
8 Mhz oscillator, gaining back 2 more I/O pins in the 18 pin package. And
at under $2 each in 100 piece quantities, it would be cost effective too.

BAJ

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads