I added an experimental mess core to Retropie yesterday. It runs coleco at 100% on my overclocked Pi 2. It requires the proper MESS software list ROMs to run in a coleco folder in your ROM directory. I can’t say for it’ll run well on a Pi 1. It also takes about 3 hours to compile on my overclocked Pi 2, so… it’s a longshot, but you can give that a try.
Thank you very much for the tip. I found out that in AdemEm the joystick settings can be set to my preferences. So I’ll keep using that one for now.