because mobile phones have simcards to access wi-fi, the modem will need to have a sim to grab the wi-fi. they wont be putting simcards in pinball modems....wont the cost of a laptop type modem be well over the top $$ wise...

does your pc have a simcard to connect to the internet?? mine doesnt, it connects to a wifi network from my router.

my ipod is wifi driven again no sim card, connects to my wifi network. pinball machine that is run by a computer isnt going to have any trouble connecting via wifi when my blue ray player does it daily for its auto updates.
My blueray player isnt magic or have a simcard it has wifi connection and it connects to my wifi network and does updates, same as my tv when it finds new firm where from samsung.
this is a great idea from JJP as stated most house hold electronics now do wifi updates. all it needs is access to a wifi network and who doesnt have one of them these days?