At 11:33 AM 4/30/00 -0400, you wrote:
>On Sun, Apr 30, 2000 at 05:01:49PM +0200, w. v. ooijen / f. hanneman wrote:
>> http://www.xs4all.nl/~wf/wouter/pic/wisp/index.html
>>
>> For my experience I think a lot of 16c84/16f84 programmers will work with
>> an '877 (with obvious limitations like 1K code),
>> but you might need the R/C trick on the VP pin (RB3?).
>
>Actually a couple caveats.
>
>1) You'll need a different bit of software. The initialization/erasure
>sequence is a bit different. Also the 16F87X parts use a 0x18 programming
>code instead of 0x08. The EEPROM data programmer also requires a bit of
>modification.

Wouter and Byron,

My $0.02 worth...

The picstart plus, and my own programmers happy program the 16F87x parts
with EXACTLY the same commands and timing as for the 16F84. That seems to
be the bottom line. The microchip documentation is all over the place
when it comes to the 16Fxxx parts. Programming time is variously given as
2mS,
5mS and 10mS depending on which document and what part you are reading.

Experimentally I have alter the picstart plus to a 5mS program/erase cycle
(0x08 command) and it worked 100% This does suggest the program time is more
like 2mS than 5 or 10.

Regardless of the conflicts in the programming specs (30925B, 30262C) it
remains that 16F87x parts do program with the same commands and timings
as for 16C/F84s and there are no shortage of examples of this.

>2) I haven't found the R/C trick necessary on the part. I simply pulled RB3
>down with a pulldown resistor. It works fine.

Right, you only need it if the pin is used for VDD on other pics like the
18-pinners. If you are not using the same socket for other parts then there
is no problem.


Regards,

Jim Robertson
NEWFOUND ELECTRONICS
________________________________________
Email: newfound@pipeline.com.au
http://www.new-elect.com
MPLAB compatible PIC programmers.
________________________________________