WARNING: Overlocking can damage your pi.
Hello,
I have been messing around with the pi 1 model b, and I have found that if you overclock the retropi, to 1000mHz, and sigificantly increases your speed of pi and are able to play emulators that you were not able to play before. This includes Sega 32x and GBA. However overclocking your pi can seriously damage your pi. This is because you are forcing the CPU to work faster then it was designed for. Recommand you do this for short periods of time, but never long term. The only Pi that you can successfully overclock is the Pi Zero, which has been designed at the hardware level to run at 1000mHz. To overclock go to retropi settings and then go to overclocking.
Also if you add a keyboard and mouse you can use the ports emulator. In the retropi settings, to to retro pi setup. Click on optional packages, that then scroll down to the bottom of the list, you will find a selection of open-source (free) games to play with a keyboard and mouse. Connect the pi to the internet and download from binary. Reboot the pi and then play. All work on the pi 1 model b without overclocking.
Thank you and regards.