Earlier than video video games, there have been pinball machines. Not that they don’t exist at this time, however a contemporary pinball machine will possible have microprocessors and different fancy issues that conventional pinball machine designers might by no means dream of. [Eli] had one among these mechanical machines from 1974 as a child and, later, encountered a extra trendy machine with a rudimentary microprocessor and different built-in circuits onboard. One factor this enabled is the flexibility to recollect excessive scores. However it’s a must to bodily take a look at the machine, and you’ll solely see the highest 4 scores. [Eli] determined to adapt the machine to add excessive rating information to the Web, and it’s a enjoyable venture.

[Eli]’s design objectives had been to make it computerized and sturdy. That’s, if the community is down or the machine loses energy, you shouldn’t lose excessive rating information. As well as, he didn’t wish to change the looks or injury the 40-year-old machine. You’ll be able to see a video of the way it all turned out beneath.

The Laser Cue machine is one among many constructed across the “Williams System 7” platform. A 6808 CPU, together with some I/O chips to handle all of the lights, sensors, and bells. The sport has solely 1K of RAM, 12K or ROM, and 128 bytes (no prefix, simply bytes) of RAM with battery backup. There was even a standard “working system” known as Flipper ROM, and that’s truly documented over on GitHub.

Because the reminiscence for the machine is all in exterior chips, it was an affordable thought to interchange the CPU with a board that monitored indicators on the board. The CPU would plug into this new board, after which a more moderen microcontroller with an Web connection might snoop on bus visitors. Nonetheless, eradicating the outdated CPU and jamming pins into the traditional socket was worrisome, so as an alternative, [Eli] elected to faucet right into a check connector that was already on the board however not plugged into something.

An ESP32 is greater than able to the speeds, though connecting to five V logic was a little bit of an issue. The CPU has 5 V tolerant pins, however among the 25 accessible pins on the event board both set gadgets on boot or could briefly be outputs and had been thus unusable. To scale back the required pins, [Eli] determined to do among the decoding in separate logic. As a substitute of utilizing TTL chips, he elected to make use of a programmable logic array.

After that, it appeared it might be easy, however there was one thing stopping the ESP32 from studying every bus cycle. [Eli] by no means bought to the underside of it however as an alternative switched to the Raspberry Pi Pico W. Utilizing the chip’s particular I/O processors made the job straightforward, and it labored completely. The remainder of the venture was simply match and end. Be sure you learn to the tip to seek out out the teachings discovered which could enable you to in your subsequent related venture.

A contemporary DIY machine may even have an FPGA inside. Don’t have room for an enormous full-sized pinball machine? No drawback.