>>11954837
>>11955280
For what you will need, at the very least a DE-10 and 128MB RAM module, though I would highly recommend at least the USB hub and Analog board as well, this is the most common setup, some refer to it as the "sandwich". If you want it to look nice or keep the dust out you can get a case for it too. There are many pre-assembled ones like this, such as the Mister Pi from Taki (Though assembly is literally just plugging about 5 parts into each other, it's very simple)

If you want to use original controllers you will need SNAC adapters for the systems. Each system has it's own SNAC adapter (Though a few can be used across others, such as the SNES adapter to use SNES controllers on a NES, and I am pretty sure the Genesis one will work for Atari 2600). Note that for any system other than the PS1 or N64 you will need a Level Shifter. Most of the cheaper SNAC adapters will not come with one on-board, but most places selling SNAC adapters will sell the level shifter too. You will need it for any system that ran on 5 Volts (pretty much anything other than PS1 and N64) instead of 3.3v to not risk damage. It's a tiny thing you will plug into the SNAC port first then plug said SNAC adapter into that. (That's what the long adapter you see on the right of this image is, though there is a new version that's much smaller)