port = connection to some other logic device, serial printer whatever, connect a inductive load to logic and see how much it can handle }

drives usually connect to the power supply in a direct fashion, and yea tap away if it looks like something you can drive a lamp from, that is why power supplies have lots of beefy caps and large diodes

macs of course dont have different floppy power connectors, they just pipe the power up the ribbon cable but its connected to the power supply, I always kinda thought it was shady that 30guage wire has a lot of resistance and can only handle ~800ma before it vaporizes somewhere