IMHO the only classics that would use more power would
be the VAXs etc.
C64s, Apple IIs, Atari 2600s would take a lot less power then a PC with
128 MB RAM, PIII-500, hard drives, CD-Writers, 3D graphics card (with
its
own cooling fan and 64 MB RAM)...
That may be true for PC's where the CPU draws upwards of 40 watts
on it's own but G3/G4 Mac's are a different story since the CPU tends to
draw considerably less, in the area of 17 watts. Plus, for the classic
consoles you name above, you'd have to factor in the television set used
for the display which, if it's an older set of a similar vintage, would
draw a decent amount as well. Of course, my MicroVAX II makes a nice
space heater when it's powered on and all it's fans are running!
Jeff