Justin Grimm wrote:

> Because Im using the c74 mainly for the PSP, I might not use rb6 and
> rb7 for I/O, just for the ICSP, so in that case I would probably just
> need to tie them to ground through a 10k resistor wouldnt I?

  If you do not use them in your application, you define them as outputs
in your initialization, and you connect *nothing* to them (other than
the ICP connector and an unused pad in case you later *do* need to use
them for I/O).

  The only reason for 10k resistors is to permit them to be inputs
normally and inputs/ or outputs during ICP.  If you were to use them as
outputs, you would not be isolating them with resistors; you would
either consider the device they drive to constitute a trivial load, or
you would have to isolate them fully (via a jumper on the ICP connector)
during programming.

> Also I take it that the chip would go immediately into pgm mode on
> startup and wouldnt get a chance to start running the program, I take
> it this is what you mean by tying osc1 to ground, Andy.

  Certainly is what he meant.  Of course, this doesn't work for a 12C50x
when programmed for internal oscillator, but you've decided to use
something else.
--
  Cheers,
        Paul B.