I'm currently using the Paralax programmer (Now Tech Tools) for in-circuit programming. I had in-circuit in mind during the board design Mostly entailed bringing all the programming pins out to the connector, even though the 2 extra lines this meant would only be used at 1st test to insert the code. Also, an op-amp output to a pin was isolated by a 1K resistor. The only purpose of this resistor is to allow in-circuit programming. I did modify the programmer slightly. To keep extra lines on my connector to a min, I use the + power line to my board (which is designed to run off 18 to 32 volts) I use the switch 5 volt power to turn on a transistor driver that just supplies the programmers raw dc in to the unit being programmed. The unit works well for programming production units. My only beef is for now I'm stuck using the Tech Tools program for this task... I'd much prefer to have my own program doing this task (that way I could make the UI geared to the product I'm building, not a chip that happens to be inside it). At 09:05 AM 6/17/99 -0700, you wrote: >Is there a modification you can make to the picstart (a buffer, etc) >that will allow it to program in circuit? Is there another relatively >inexpensive programmer that will do this? The microchip pro-mate costs >$1000, which i will spend if we go into production with this circuit, >but for prototyping, it's a little high. > >Thanks for any help, >eric > >Eric Hufstedler >Kilovac Division of CIIT >Research & Development >805-684-4575 x152 >erich@kilovac.com > >