At 11:42 08/10/97 -0400, you wrote:
<snip>

>I like the advice given by the others on the list. I have a little $50
>programmer that will do most of the 16xxx series pics but since I have
>wanted to experiment with the 17xxx and 14xxx seriesl, as well as the
>16c5xx so I wished that I had a more universal progammer.

Hi Sean,

   I've been thinking about designing a parallel programmer for 17Cxx for a
while. It would be easy enough to add a socket for serial programming of
other PICs too.

I don't have time at present, but here's the idea. All it needs is to
74LS299 shift registers, two transistors and couple of voltage regulators.
You could hang the whole lot on the parallel port.

Two port pins control the 5V and 12V supplies through transistors. You shift
data into the shift register with two port pins, and one other pin to handle
the load/shift signal.  The other end of the shift register is connected to
one of the inputs of the printer port so you can read data back. Connect PA0
and PA1 to two port pins and off you go.

The software has to read a hex file, and program each byte in turn. Probably
quite feasible in VB.

If you're interested drop me a line I'll send you a schematic of my idea
(partly pilfered from lots of other people.)

Keith.
------------------------------------------------------------
Keith Dowsett         "Variables won't; constants aren't."

E-mail: kdowsett@rpms.ac.uk  or kdowsett@geocities.com

WWW: http://kd.rpms.ac.uk/index.htm
     http://www.geocities.com/CapeCanaveral/Lab/8979