Do all computers and turtles use the same startup?

I want to edit and use startup program on some computer. which will be different program. But I realised in my mc world, they uses same startup program. Is this normal?

If it is normal,
Is there anyway for using different startup programs?

All computers execute /rom/startup when starting up, but they all also execute their own /startup program, if present. That one is specific to each computer and not shared.

Lyqyd, on 17 May 2014 - 08:05 PM said:

All computers execute /rom/startup when starting up, but they all also execute their own /startup program, if present. That one is specific to each computer and not shared.

so i have to save startup program on disk? or is there any other way?

and what about turtle, what do i have to do for different startup program on turtles?