Hardware and drivers

Dear All

Can somebody help me how H/W and H/W drivers will affect the application?

When I port my application from HP-UX to Solaris should I take care this area? What are the application touch point in H/W or H/W drivers on these two O.S.?

If it's a 3rd party application such as Oracle or Sybase, then information on a move from HP to Solaris would probably be on the applications web site.

If this is a in-house application, then it will matter how the application was coded.