the power supply connector for the zip is bigger. it's like the one's that connect to hard drives or cd roms in your computer. i just cut off one of those from my computer's power supply and connected it to my mpc's power cable but i wouldn't recommend it, i got a cheap old computer.
there's a tutorial on how to modify and connect the cables at mpc2000xl.com.
i personally found it to be really easy, it was like connecting speaker wire.