Lpc2000

While a good idea from an engineering perspective, remember that 
RS-232 drivers are meant to survive dead shorts, including shorting a 
high line to a low line (+12 to -12).  The circuit may not function 
correctly, but it won't (shouldn't) blow the driver.

    --jc

haack0815 wrote:

> Hi Richard,
>
> i think the position of D3,4 is wrong.
> What happens when DTR or RTS  are '1' (negative voltage)?
> You better place D3,4 behind the 33k  resitor to protect the drivers
> of your PC.
>
> Andreas
>
> --- In lpc2100@yahoogroups.com, "Richard" <richas@y...> wrote:
> > I have uploaded this version to the files area.  I also uploaded a
> > picture of the required circuitry.  This circuitry is already
> > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. 
> > It is really handy as ISP development can be done relatively quickly
> > and "hands-off".
> >
> > Cheers
> >
> > Richard
>
>