If your A4000 has PCI slots then its ez and cheap, even free.
If you don't have PCI slots then good luck.

Cuz the only really easy way would be to use dialup with an old modem.
I have seen ppl sell Ethernet cards for A4000 but they charge half the price of adding PCI slots so... its just not a really good investment. But of course you are free to do whatever you like
