Dropped more than a few quarters here. And spent a lot of time getting it to work on my iPad.
JSMESS is a port of the M.A.M.E. emulator, and shares the keyboard mappings of that system. Pressing the 5 key will insert a coin. ( A lot cheaper!!!)
Like number one.
Showed this to one of my grade seven students. She looked at for quite a few minutes then started smiling.
Helps to read and check as well, However, this is a nice graphic.