Port pin problems

Using a 17C756 with select case statements to set pins on a give port. Each time the routine executes with in the case structure ( if then else also) to set (1 or HIGH) all pins on the port are reset (0 or LOW). If a pin is set one one port say PORTD it does not effect other pin of ports PORTF, PORTE and so on. I have tried simple implied Let command s( Var = 1) and the HIGH Var form. Neither works.

The pin names are defined variables which are then used in the body of the code.

Anybody know whats going on.

If you post your actual code and definitions, then folk might have a chance identifying what your problem is, or trying to replicate it, otherwise it's kinda stabbing in the dark.

I turns out that the 17C756 defauts to A/D analog inputs on the two ports I was working with. Melabs set me straight.

Everything now works fine.