On Mon, Feb 06, 2006 at 09:03:15AM -0200, Gerhard Fiedler wrote:
> Byron A Jeff wrote:
> 
> >>>> Are USB-parallel converters common at all? To be honest, I have not
> >>>> seen a physical one yet. USB-seral converter is much more common.
> 
> >>> Both in the computer shops in town and at my main supplier they are as
> >>> common as a serial converter, and cheaper. [...]
> 
> >> But it still costs $13 (and the warranty sounds kind of strange). If the
> >> goal is to make a low-cost PIC programmer, a programmed PIC for a "real"
> >> programmer is probably cheaper.
> > 
> > I started this thread. Cheap isn't the sole goal. Part of it is to maintain
> > some measure of control of the hardware. [...]
> 
> > So the cables represent one of the few commodity links to allowing for 
> > direct control of hardware on a PC.
> 
> I still question the means... between 
> 
> 1- buying a commercial USB-to-Parallel converter to be able to wiggle some
> pins in a limited way and building a limited programmer around it, and 

It's not just about programmers. Parallel and serial ports over the years
have been used to interface to a wide variety of hardware. Consider the
X10 Firecracker and LIRC interface hardware as examples.

> 2- buying a programmed PIC to do exactly that (wiggling some pins) in a
> much less limited way (and then build the rest of the minimal hardware
> around the PIC), 
> 
> to me the second version looks more "in control", more "DIY".

I would agree if all PICs came with bootloaders on them. However, when
you get samples from MChips, or purchase from Mouser, DigiKey, Jameco,
or even Randy from GlitchBusters, they come blank. 

Remember that in my world view, programmers are not important. They only
function they serve in to install bootloaders into blank chips. So I
firmly believe in being able to perform that activity with commodity
components (emphesis on commodity).

Your second solution requires that you purchase from a specialized
vendor, such as Wouter or Olin for example.

BTW I think that USB to serial is a better investment.

BAJ
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