Gday Pete

"I tried chip = porta.0 and it won't compile."

Oops sorry, my mistake when cut and pasting.
( You know what they say about shortcuts )
The "chip var porta.0" syntax you arrived at is correct, and same as my referenced example.

"high chip [x] doesnt work"

I used "xport(k) = 1 ' set pin high" syntax
as it uses less code than the high command ( apparently )
I was testing using LEDs, so i know that it worked in that mode.
However your syntax shld also work.
Based on yr cut and paste, there is a space between chip and [X].
If this is so, remove it and retry. Shld work then.

Andrew