> -----Original Message-----
> From: piclist-bounces@mit.edu 
> [mailto:piclist-bounces@mit.edu] On Behalf Of Byron A Jeff
> Sent: Monday, February 06, 2006 9:15 AM
>
> On Sun, Feb 05, 2006 at 01:59:15PM -0500, David VanHorn wrote:
>> So do it at a higher level.  Send a hex file to a chip on 
>> the other side of the USB interface, and let it do the pin 
>> wiggling, reporting back success or failure as appropriate.

I believe GTP-USB (with WinPIC800) is doing this since WinPIC800
support simple serial Port based JDM as well using the same
host software. It is using the 18F2550 as the USB interface and 
not those common USB-to-serial chips. I am not 100% sure though
since I have not tried it and both the firmware and the
host software are closed source.

> 
> As I said before the USB/serial (or possibly USB/parallel) 
> cables represent compromises as they are easily obtainable 
> and have more than one purpose. 
> 
> So the job becomes how to use such cables as interfaces. 
> However, they do not have the same level of accessibility as 
> the native ports they replace.
> 
> I believe that it's a problem worth figuring out.
> 

I believe this is an interesting problem to figure out as
well. I think USB-to-serial converter will be more
common and more useful solution than USB-to-parallel 
converter. I agree with you it is worth to investigate
the possibility to produce a reasonably simple programmer
based on USB-to-serial converter and it needs only to support
popular PICs like 16F88/16F876A/18F2520/18F2550 to be
useful to hobbyists. And a bootloader solution is not bad 
as well for 16F88/16F876A/18F2520/18F2550. In fact I
like the bootloader function of PICkit 2 very much.

Still I think the chicken-and-egg problem is not as important
as you might think. Anyway, one needs to invest some time and
money to get into the PIC world. Programmer is only a 
small part of the total investment. To me a multimeter and
an oscilloscope are much more essential than a programmer. 
Guess I am a bit biased since I am an electronics engineer.


Regards,
Xiaofan 

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