PTCD(4)

📦 version 11.0, in nixpkgs unstable

💸 PTCD(4) — the Protech PS3100 cash drawer port girlie 💅

okay so real talk, this is page PTCD(4) from the Kernel Interfaces Manual, and it's all about the ptcd driver — support for the Protech PS3100 cash drawer port. yes bestie, a cash drawer. we love a niche little driver that knows exactly what it's about 🎀

✨ SYNOPSIS ✨

ptcd* at isa? port 0x48d
gpio* at ptcd?

that's it. that's the whole configuration. short, sweet, iconic 🌸

🦋 DESCRIPTION 🦋

The ptcd driver controls the cash drawer port of the Protech PS3100 point of sale terminal, and it does it through the GPIO subsystem. teamwork, fr fr 🫶

ptcd hands you a GPIO device with two pins:

  • pin 0 — this one controls the cash drawer. it's the main character 👑
  • pin 1 — this one reads the current state of the sense input pin. the observer. the vibe checker 🌈

and the logic is genuinely simple:

  • a logical 0 means the cash drawer is closed 😴
  • a logical 1 means the cash drawer is open 🔥

💰 how to actually pop the drawer

to open the cash drawer, set pin 0 to logical 1 for a short period of time (e.g. < 1 sec) and then reset the pin back to logical 0. that's the whole ritual. brief little pulse, drawer goes cha-ching, we move on with our lives ✨

ngl, "short period of time" is doing a lot of heavy lifting here — the example given is < 1 sec, so keep it quick, don't just leave that pin sitting at 1 like it pays rent 💀

🔍 SEE ALSO 🔍

go read those too, iykyk 📚

🕰️ HISTORY 🕰️

The ptcd driver first appeared in NetBSD 6.1. a lil vintage moment 🎀

👑 AUTHORS 👑

The ptcd driver was written by Marc Balmer <marc@msys.ch>. thank you marc, king behavior 🙏

⚠️ CAVEATS ⚠️

okay bestie, listen to me very carefully, this part matters 😭

As it is not possible to detect the hardware at runtime, this driver, when enabled, will always attach. no vibe check, no "are you actually there?", it just shows up. so only enable it in your kernel configuration if you have the proper hardware. periodt. 💀

fr fr do not enable this just to see what happens — it will attach regardless and that's the whole warning 🚨

Debian · December 17, 2012 — mwah, that's the source, the version and the date, all tucked into a cute lil sign-off. go pop that drawer, babe 💖🦋🍓

📦 where this page comes from