At 02:19 AM 11/16/2006, Bob Axtell wrote: >I have noticed that the PIC12F and PIC16F don't bog down if the PGC or >PGD pins drive the next >stages thru a 22K resistor. I know that is very weak drive, but it works >fine for some low-speed tasks, >such as driving a schmitt-triggered 74HC14, etc. I've also mentioned in past how I use what I call my "stoopid buffer" to buffer both the PGC & PGD pins - this works well even with heavy loads on the pins. One card has 470R loads on the programming pins, the other has 1K loads. MCLR/Vpp was designed to tolerate the presence of the programming voltage (series R). We built a little card that has the Vdd and Vpp buffers as described in a Microchip app note as well as those "stoopid buffer" circuits. Its been working well for the past several years with both PS+ and DIY K128 programmers. It has pins on the bottom that drop into the ZIF socket on the existing programmer and a connector for our ICSP cables. I've really got to get some time freed up so that I can properly document this stuff and get it on a web-page. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 22 years of Engineering Innovation (1984 - 2006) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist