> the PSX needed a modchip soldered in the mainboard
Nope, the way people played copies on the first PS1 (before the modchips arrived) was to use a spring loaded weight ($5) on the door sensor, boot a legit disc and then swap to the copy after the boot sound. No modchip required. The Sega Saturn required a mod, but it required no chip, just a few wires and a switch.
If you didn't want to "spring for the spring", so to speak, you could do it manually with a little more difficulty.
On the Dreamcast it was all software, not even a jailbreak, just some code on the pirated game. It left no traces, you could boot a legit disc and connect to SegaNet, try doing that with LIVE and not get banned.
Right now pirating on a X360, either with LT, RGH or JTAG takes so much work the vast majority of users don't bother to even try, but if it was like the Dreamcast you would have a totally different situation.