On Nov 5, 2006, at 1:52 AM, Howard Winter wrote:

> Looking at http://www.olimex.com/dev/images/pic-pg4d-sch.gif
> it seems to be using pin 3 of the "PGM" socket to supply the 13V
> programming voltage, so as far as I can see you'll need to supply
> this yourself.  There is no way it can generate the programming
> voltage on the board - there's just no circuitry to do so, unless
> I've missed something!

The JDM style programmers play loose with the definition of "Ground"
and rs232.  Since a 'real' rs232 port has 18+ Volts between the most
positive and most negative signal levels, generating 13V is no problem.
(then came laptops and such operating closer to +/- 5V for rs232 and
such, and as many people have pointed out now, a USB-serial converter
can't usually manipulate the rs232 control signals fast enough to do
the programming, even if it does generate full voltages.)

BillW

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist