On Mon, Jul 19, 2004 at 08:31:37PM -0400, csb wrote:
> Hi!

>   I just got my first pic, a 16F84A a few days ago.

Congratulation! I offer some suggestions to get you up to speed.

First of be aware that the 16F84A is generally considered to be obsolete for
new designs.I outline the discussion on my 16F84 is obsolete page here:

http://www.finitesite.com/d3jsys/16F628.html

I need to update the page to reflect that the 16F88 is now the clear champ
in terms of the 18 pin PIC for the hobbyist

> I decided to build
> Michael Covington's NoPPP programmer (being more than cost-effective), which
> is supposed to be able to program both 16F84 & 84A.

My Trivial PIC Programmers, both low voltage and high voltage, perform a
similar function. I use a HCT part for level translation. According to
the Radio Shack Canada site, The 74HCT573 part #276-2892 has some availability.

If you use a short parallel cable, you can put together a THVP with
just the HCT573, a couple of resistors, and a common transistor like Michael
has on the NOPPP.

> Just to be sure (I would
> hate to wreck my PIC) I went in the Programming Specifications for 16F8X
> datasheet from microchip. One detail caught my attention: ( in the bottom of
> the table if anyone cares)

> Erase and Program time:         8ms for pic16F84A (the one I have),
> 20ms for all other devices

No worries. Both parts are self timed. So they finish when they finish.

BTW that's another advantage of the newer parts. The 16F88 programs 4 words
at a time, and the wait time is only 2ms. So it programs 16 times faster than
your 16F84A.


>

> I'm wondering, if the noPPP software waits for 20ms (it doesn't naturally
>support  the 84A) instead of 8ms, does something 'happen' during the excess
>12ms?  >

Nope.

One last thing. Microchip's same program can be used to experiment with
different PIC parts. You really won't regret trying some of the newer parts.

BAJ

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