OT(ish): Using "Classic" CPU as power resistor...

I need some help from those who are a lot better than I in hardware design... The problem is I need to use a PC power supply (AT-class with it's own power switch) as a 12V power source, and the only one I have access to needs a minimum load of 3Amp on the +5Volt line. By my rough calculations and allowing for wiggle room, I'd need a 20-watt power resistor of 1.5 ohms to keep the critter happy. "Bare minimum" is 15W, and I could squeak by with that if I wire the fan to the 5V line instead of the 12V... but even when I'm expected to perform a "miracle" I like to have a little wiggle-room. ;-) Problems I have are: 1) I need this by Monday, and 2) I don't keep 20-watt power resistors in my back pocket. Had I a week, I'd just order the right tool for the job - I don't have that luxury. ;-) I was thinking I *might* be able to cobble up enough lower-end power resistors & figure out how to stuff 'em together to draw 15w+ of power, but then I thought: What if I took an older 5V CPU (say... an 80486) and wired 'er up to just Vcc & Ground - how much power would that use? [[ I've started some google searches & I will continue, but I was hoping others here would have better ideas than my lame-azz neurons & google so far ]] I could also wire-wrap all the address/data lines to Vcc if that would add a enough extra current draw to make 'er worth my while... For those who are in lust with the "older, but still plentiful" CPUs like that, then turn away now, you didn't see this, I was never here." ;-) Any ideas will be most appreciated! Thanks! Roger "Merch" Merchberger