HP 48GX Ports

[Han]

Port 0 is main RAM. You always have port 0. It is necessary in order to install libraries into main RAM. Without it, you would be restricted to installing libraries onto RAM cards in slot 1 (Port 1) and slot 2 (Ports 2 and higher). You can also store other objects in ports, but libraries can only be stored in ports before being attached and hence usable.