Re: [avrdude-dev] Parallel port doesn't keep programmed states

[Jan-Hinnerk Reichert]

On Monday 24 November 2003 00:58, idefixx wrote:
> > You need to disable Windows XP Plug'n'Play for the parallel port.
> >
> > I solved the problem with the following file:
> > http://www.student.dtu.dk/~s991363/avr/avrdude/winxp1.reg
>
> But is it really necessary to change the windows registry? What
> changes are going on during the read out of the AVR flash, as after
> doing a read out the problem disappears, too.

I don't know the windows ppi-code. However, there should be no 
difference in the called functions, since we only transfer 
SPI-commands.

I guess there is either some magic sequence occuring on the port while 
reading or (more likely) it has something to do with the frequency of 
access. For _unpaged_ memory writing does big pauses when writing. So 
perhaps windows thinks there is a valid device and stops looking, if 
there only is enough "action" on the port.

Have you tried the latest CVS source? Recent changes in the polling 
code make writes look more like reads in this regard. There is a good 
chance that this makes your problem go away ;-)

/Jan-Hinnerk