parallel port hardware theory

I have a theory concerning on my previous message, and I need ideas (code)
to probe it.

The theory is:

-The parallel port has a hardware flag, that informs to the software if the
port is busy or not.

- both inb() and outb() functions, have an early line that looks for the
hardware flag, and keeps waiting until the flag becomes to NOT BUSY, then
continues the port access

- the 1 [usec] delay becomes vissible only when 2 o more consecutive IO
calls are made.

Thanks in advance to whom can help me with this.