> Why is it that some programmers (wisp628, kit 149, GTP-USB, etc)use PIC=
s in them to controll programming?
> If the old programmers like icprog or elcheapo are able to control the =
clock, data, and mclr lines, why can=B4t you just add support for newer P=
ICs to their software. As far as I know all(?) PICs use the same method t=
o load data into them.
>
> Is there any good reason to use controllers inside programmers VS compu=
ter controlled lines?

I don't think there is a reason to have a PICmicro rather than any
other microcontroller (except that you're working with PICmicros
anyway, so why not stick with what you know) but I can see a
microcontroller having distinct advantages in the form of ensuring
timing and allowing longer cable lengths.

I can also tell you from experience, that even with a completely
compatible parallel port and serial port, the JDM and El Cheapo
programmers are NOT able to program all Microchip devices. I tried
five different software suites, but the El Cheapo will not program the
16F628A, 16F877A, 16F688. The JDM programmer is capable of programming
them, but timing wise it is already on the edge, meaning that any
disturbance will have bad results (especially if you're doing the full
8KWord of the 16F877A).

As said earlier, I didn't know all this until I got a PicKit 2 (of
which the USB interface installed like a breeze, by the way, on all my
computers) and discovered the pleasure of a programmer with a PICmicro
inside it.

This doesn't mean that the JDM is a bad programmer. If your serial
port is "proper" (-12V to -15V and 12V to 15V signal levels), and you
keep your cable short enough, it will work fine.

Greetings,
Maarten Hofman.

--=20
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