I work for a software company and when I describe EM machines to incredulous coworkers, I stumble when trying to come up with a number representing the amount of logic circuitry in a typical game. Any good estimates for this?

I see Clay mentions "just a couple bits" but surely it's more than that (though still not a lot). Say a machine has 30 relays, and each has an average of 4 switches, isn't that already 120 bits? Throw in 4 steppers with maybe 10 contact points each, and you're working with a total of 160 bits, divided by 8 = 20 bytes.

Perhaps I'm being too simplistic in this estimate. I see xsvtoys mentioned going through all the logic in #BonVoyage on his restoration project thread (great game, need to do more work on mine), but I didn't see a conclusion. Curious what others think!

I'm definitely interested in the byte count needed to represent the logic, as a way of saying "all these wires, relays and switches you see (and smell) in front of you represent XXXX bytes of information".

And to be fair to &cfh, who I quoted originally, I think he might have meant a few bits of *memory*, specifically, which I guess is different than the overall logic. A toggle switch is kind like memory, isn't it, i.e., permanent until changed?

Anyone prepared to hazard a guess like a Fermi Problem? Maybe starting with an order-of-magnitude estimate: 10 b, 100 b, 1 kb? With 300 switches in a Bon Voyage, naively dividing by 8 puts the number near midway between 10 and 100. More sophisticated reasoning about how much a switch contributes to overall logic might bring that number down.

So if went shooting off my mouth with my coworkers (or with my boss, usually the smartest guy in the room) and said "All this crazy stuff adds up to 32 bytes" (a nice round byte count number), would I be lying or well within margin of error?

I'm not totally sure how to look at ROM files or if it's even legal, but I went to Planetary Pinball's early Bally tech page which has ROM downloads. Mata Hari has two files, 2 kb each. Are we really saying an EM therefore would typically be 4 kb? Seems high to me. Couldn't this code be full of all sorts of extraneous stuff, maybe even comments or redundant hash tables and whatnot? I'm not actually an engineer that gets anywhere near silicon (or machine code for that matter), so I might be way off base, but call me skeptical of this approach.

Really enjoying this thread, btw, really eye opening stuff!

Just to summarize where this seems to have left off, I think the fair answer seems to be: "Up to, but probably no more than, a couple hundred bytes".