Re: systemd? Do not want.
"30-year old electronics."
No. These days, it's run by an aging headless Slackware laptop running a CP/M emulator. The original control code has mutated slightly, as I've had to replace hardware in the trenches over the years. I have the original hardware, it might still boot, but I'm planning to bring it up gradually in a restoration.
 HP hardware, circa 2003. Pre bad-capacitor HP.