>Keith Dowsett wrote:

>> Hi,
>>
>>    I built a ProPic a little while ago and used it mostly for 16C84
>> development without any problems. Octavio was pretty helpful and suggested
>> adding a little capacitor to one of the data lines when mine wouldn't
>> program.  When I get some time I will add the production programming
>> options, and start on a 16C73 project I have in mind.
>>
>> I will probably re-design the power supply to use a 317 for the programming
>> voltage instead of the 7808. This will allow me to adjust the program supply
>> too.
>>
>> I built mine on strip board, but if you fancy designing a neat PCB for it I
>> would love a copy. Octavio could probably post it on his page too.
>>
>> Keith.


>Thanks for your reply Keith,
>I will be using the programmer on a '84 as well and then will
>probably progress to a '74.
>As for the PCB I will probably use stripboard but might design
>a PCB layout anyway with Autotrax.
>By the way where does that little cap go...
>Thanks
>Justin
>

So far as I remember (it's at home at the moment) the old design it needed
about 300pF on the clock and data lines to the PIC. I think the current
version has a slightly different buffering arrangement.

Let me know how you get on,

Keith.
==========================================================
Keith Dowsett         "Variables won't; constants aren't."

E-mail: kdowsett@rpms.ac.uk
WWW:    http://kd.rpms.ac.uk/index.html