Game System Emulators

[ComputerWizKid]

I have a bunch of emulators to play the old NES and SNES and sega games but I'm wondering how do people make the roms you downlaod?

 

[PottedMeat]

just a guess -
crack a cartridge open,
look up the data sheet on the read only memory chip,
hook up a device to read each memory location and save the contents to a file
-one way would be a program a microcontroller to generate a clock and clock in read commands
and send the responses to a computer via serial port maybe
the file is basically a exact copy of whats on the chip location for location so the emulator acts as if the file was the rom

 

[walla]

There are also devices sold commercially that let you "back-up" your ROM from the cartridge (such as flash linkers).

I suspect these are the types of devices that most people use to generate the ROMs that so many people download and illegally use.

And I suppose you could also use a microcontroller and directly address the ROM in a sequential manner in order to produce a ROM copy.