One of the wild things about learning to repair old #pinball machines is trying to reverse-engineer dead concepts. There are things that were duh-obvious to the creators that I have to painstakingly deduce over days of effort.
@williampietri
As an avid player of older old pinball, I can maybe assist with that. The latter day old machines, not so much.
@williampietri
Well, the credit relay has relationship to other things besides the coin relay, for starters.
On a machine where you can earn bonus credits, the condition for the bonus has to be triggered as well.
@williampietri
The earliest basic pinball machines didn't count on people getting good at it, or manipulating the entire machine body to get a remarkably high score, so a TILT mechanism was added later but not a whole lot later.
A TILT condition would wipe out both your score and your credits and lock up the machine until a new coin was inserted.
Every progressive version of pinball always made playing the game harder than earlier versions.
@williampietri
Long story short, one coin gets you a certain number of games (balls) and each game = one ball in play; game over when the ball went off the board.
A coin starts a series of games (credits) when inserted, and you could add coins even before playing, for multiple credits, and the machine gives you one ball at a time.
A game starts when you put the ball you've been given into play on the board. The credits actually count how many balls you're entitled to and subtracts each ball as you play them.
Scoring more points than the machine is able to count is called a roll-over and it earns you a bonus credit.
Beyond the basics are certain targets or bumpers that get enabled to double your points but only during a certain period of time but don't when they time out, and such features add other ways of earning extra credits besides the roll-over.
....so yeah--the later the vintage of the pinball machine, the more complicated the credits thing gets. Hope this helps.
@ClaraListensprechen4
Sure! The current thing I'm puzzling over is the relationship between the coin relay and the credit relay. In modern machines, the mental model is "put in coins for credits, use credits to play". But there's some complexity to suggest that there was an older mode where putting in a coin started the game directly. Have you seen that in action?