hidden machine stands for HM so any place there are hm's that's what your looking for. they are usually in a variety of places, but most are obtained from people in houses in certain towns, and you can only use them after you defeat certain gym leaders. when the gym leaders say "now you can use hm05 outside of battle" or whatever hm, you know that the hm was found most likely in that town, or the town before, or in between.
to get a hidden machine for Pokemon sapphire you have to..... ask someone else because i don't know
Regirock, Regice, and Registeel.
yes in emerald there is a cloning machine where you can double your pokemon.
hidden machine
Absolutely!
You press A at the machine.
Hidden Move 8.
Hidden Machine
If you meant TM10, that's Hidden Power
strengh
the TM 10 in emerald is hidden power. te attack power varies among different Pokemon. accuracy:100 pp:15
you win them from gyms