Previously, it was the same as others - put roms in, emulator plays them scaled up to your LCD. You'd do well to avoid it's underpowered ARM CPU and crap GPU in favor of an abandoned ancient laptop with a dead battery, but a decent Nvidia Mobile GPU, a PSP, Your phone, but pair a bluetooth controller, or best case scenario, someone's grandma's abandoned wii-fit and a chinese 3rd party component cable to set up on a CRT to get real 240P better than all your old console's output for damn-near free.
I can agree on all the negatives everyone's got so-far.
I'll list the low points here off the top of my head:
A 10 year old PC can easily do better
The analog audio is crap - a handful of surface mount transistors, resistors and capacitors do a bad job of proper d-a circuits - the audio hurts brains.
It's an ARM CPU - it can't play anything past 4th gen consoles any good, and doesn't have enough power to even do most MAME games properly.
Off the shelf it can only output composite 320x240 or HD fixed-resolution HDMI.
Now the reason I think it actually matters now:
http://www.rgb-pi.com/Watch the
VIDEOActually the experience - no fakery just bad cinematography and crap TV speakers here...
It uses modified retropie profiles per-core to achieve 1:1 15khz video for all the old consoles and all the mame games as well.
Even when a rom comes up that is unrecognised and therefore a perfect video mode cannot be forced, it simply forces 1920x(whatever) to minimise shimmering and fake a perfect video mode with a best-case substitution.
It will force games that don't fit into SD progressive modes (like vertical mame games forced to horizontal viewing) to either scale or crop (your choice every time until you force one decision).
The analog audio doesn't suck, but a few days ago there was a new revision that improves it (actually sounds great on my older model - didn't have a complaint)
I haven't tried a lot of PS1 games yet, but it does play the ones I tried just fine, no problems yet.
I fully endorse this. It's actually fully set up and works great out of the box unlike every system I've been messing with to force 15khz RGB into up to this point.
It's not as good as a PC, but easily beats a modified Original Xbox which is a pain to force out of interlaced modes.
It's a good deal compared to any other solution as far as rom compatibility goes.
I'm not going to abandon my old solutions to get games running perfectly on CRTs, I still prefer the better control and customization and all that a CRT Emudriver hacked video card in a PC with an Intel core I chip provides, but compared to anything you can just buy and plug roms into and then plug into to a CRT, this is amazing! It's cheap and easy and outputs perfect video for almost every game. If you wanted upscaled video you'd already have an Android device or modified (or VC) Gen 6+ console plugged into a flat screen HD TV.
This will on startup accept any USB controller and configure the emulators to accept its input.
Not love, but acceptance into my hardware solutions for sure.
I hear from the author that he is now working on a jamma plug'n'play solution. Follow his twitter for updates on that.