NES question - substitute of the 7805?

[Meff]

Everybody knows 7805 is good for regulating voltage higher than those 5 volts, but what when the batteries go below or near this value? Some screens are also powered by +5V, so when batteries are near that value, it will still work, and even when they still go below that, it should work for some amount of time. But 7805 needs higher voltage to work properly. Do you know any other solutions that would have less power consumption? I heard something about buck-boost dc-dc converters, but couldn't find nearly anything about them here in Poland.

[vskid]

This should work as long as the NES draws less than 500mA. It'll work with higher, lower, or the same voltage as the output.

[nevermind1534]

One of the PTH08000 or PTH08080 regulators that everybody uses for N64 portables will also work. I can get you one for $15; PM me if you're interested. The regulator that vskid linked to also looks good, though.