I'll try my best to explain with my electronics hobby background...
It's full of analog circuitry like integrators, comparators, op amps etc (note: it's made from discrete transistors, so you won't find an opamp chip in there). The "state" as you mentioned is maintained as a a voltage.
The velocity of the ball is stored as a voltage, and the position is produced by integrating that with an integrator. Collisions are found with a comparator, and connected to the circuitry that maintains the velocity.
The output to the oscilloscope is two voltages that control the position of the beam.
Analog electronics is one of those dying art forms where the number of people capable of doing things like this is quickly dwindling. It's no longer a viable way of building actual products except for a few special applications.
I find it a sad state of affairs that we, the mankind, have learned and developed skills and knowledge that we'll be collectively forgetting less than a century later.
I find it hard to believe that analogue electronics is disappearing. I'm an undergrad ECE student and the largest part of my course is analogue, with work in labs too. Granted, it's not an immensely popular hobby, but many art forms and jobs are necessary but aren't hobbies.
If it's RF, or chip-surface level - there's analog in there somewhere. While digital logic is somewhat forgiving, for production level work you do need to have some understanding of analog to make a successful design and stable implementation. Plus there's always the power-supply stuff, and a bunch of other things that will always be analog as well. So I agree that it won't completely die off (especially in the commercial realm) - but it certainly isn't as common in the hobbyist world as it once was.
/saying this as someone who considers analog a black though beautiful art
There is plenty of analog work in the RF engineering careers. I mostly do digital but most of my coworkers started out and currently work on analog boards. Although we are moving a lot of our stuff to SDR so the RF board in the product is just getting smaller but needs to be able to handle larger bitrates.
It's full of analog circuitry like integrators, comparators, op amps etc (note: it's made from discrete transistors, so you won't find an opamp chip in there). The "state" as you mentioned is maintained as a a voltage.
The velocity of the ball is stored as a voltage, and the position is produced by integrating that with an integrator. Collisions are found with a comparator, and connected to the circuitry that maintains the velocity.
The output to the oscilloscope is two voltages that control the position of the beam.
Analog electronics is one of those dying art forms where the number of people capable of doing things like this is quickly dwindling. It's no longer a viable way of building actual products except for a few special applications.
I find it a sad state of affairs that we, the mankind, have learned and developed skills and knowledge that we'll be collectively forgetting less than a century later.