On Sun, 23 Jun 1996, NEIL GANDLER wrote:

>  I recently purchased ITU technologies PIC-1 programmer that claims
> in their web page and also by phone that it supports in circuit programming.
> After receiving the programmer, I have no idea how they expect it to work
> that way. Just curious if anyone has a clue.

The PIC-1 supports in-circuit programming to the extent that most any
programmer for the 16Cxx chips do: the serial protocol uses only a few
pins,a nd with some care in the design of the circuit you can drive those
pins from the ITU-1 without pulling the chip from the board.

It's not described in any detail because, I suppose, they assume that
anyone who can design the circuit so that it will work with in-circuit
programming will have no problem figuring out how to connect the circuit
to the header (or the on-board DIP socket if they've dropped the header
in the 1a revision of the board).  I think there are some hints in the
device's programming spec from Microchip.  Basically, you have to design
so that the programmer can provide power, the programming voltage to
MCLR, and drive RB6 and RB7 (for the 16C7x parts) without either damaging
the surrounding circuit nor being excessivley loaded down by it.