Hi,

is it a Tait-style programmer? (Schematic may be found amongst others at
B. Dobaj's home page)

Imre


On Mon, 22 Nov 1999, Kyle Stemen wrote:

> I am trying to make my own programmer for the PIC16CXX series. I have
> gotten to
> successfully work with the PIC16C74A, but it does not work at all with
> the PIC16C64. My
> programmer interfaces through the parallel port. My VPP is very close to
> 13 volts.
>
> What could the problem be? All of my timing is extra slow. Is there a
> limit to how long I can
> wait? The specifications do not mention any limit. Does VPP have to
> first stay around 5V
> before it goes up to 13V? What kind of voltages are needed for a logic 1
> and 0 on the data
> and clock lines? When the PIC is outputting data how much current can it
> sink or source? Is it
> ok if I keep the power on most of the time, even when VPP is not on?
> What differences could
> the be for programming between the PIC16C64 and the PIC16C74A? I have
> checked both chips
> with the official programmer and they both work
>
>