UMCT(4)

📦 version 12.2, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 UMCT(4) 💖

okay bestie, gather round, because today we're talking about umct — the Magic Control Technology USB-RS232 converter driver ✨ she lives in the Kernel Interfaces Manual and she is, lowkey, a whole vibe. 🦋

🌸 NAME 🌸

umct — Magic Control Technology USB-RS232 converter driver

the way that this is literally just the driver's whole government name 💅

✨ SYNOPSIS ✨

okay so there are two ways to get her on your system and I'm gonna walk you through both, no cap 🫶

option one: bake her into the kernel. to compile this driver into the kernel, drop these lines into your kernel configuration file:

device usb
device ucom
device umct

option two: load her as a module at boot time. alternatively, to load the driver as a module at boot time, put this line in loader.conf(5):

umct_load="YES"
not me giving you two perfectly valid options and you still picking neither 😭 pick one bestie, I'm begging 🎀

👑 DESCRIPTION 👑

so here's the tea ☕ — the umct driver provides support for USB to RS-232 converters based on the Magic Control Technology USB-232 design. these devices support most of the standard RS-232 features, including baud rates ranging from 300 to 115200 bits per second. iconic range honestly, from lil whisper baby to full send 🔥

however — and this is the part where we all collectively gasp — neither hardware nor software flow control seems to be supported. 😭 like, at all. so if you were planning on flow control, bestie, that's a no. not a "maybe later", not a "check the docs" — it's just not there. grieve it and move on 🕊️

access to devices under this driver is via the ucom(4) framework and device nodes. that's the doorway, that's the plug, that's the whole thing ✨

🌈 HARDWARE 🌈

the umct driver supports the following adapters — a whole friend group, fr fr 💖

  • Belkin F5U109
  • Belkin F5U409
  • D-Link DU-H3SP USB BAY Hub
  • Magic Control Technology USB-232
  • Sitecom USB-232

five absolute queens, all slaying under one driver 👑

🎀 FILES 🎀

here's where the actual device nodes live, so you know exactly where to look 🧚

  • /dev/ttyU* — for callin ports
  • /dev/ttyU*.init — corresponding callin initial-state device
  • /dev/ttyU*.lock — corresponding callin lock-state device
  • /dev/cuaU* — for callout ports
  • /dev/cuaU*.init — corresponding callout initial-state device
  • /dev/cuaU*.lock — corresponding callout lock-state device

the ttyU* girlies are your callin ports, and the cuaU* girlies are your callout ports. and every single one of them has an .init twin and a .lock twin, because nobody here is doing anything alone 💅

💜 SEE ALSO 💜

go read these too, iykyk 🫶

tty(4), ucom(4), usb(4)

🦋 HISTORY 🦋

the umct driver appeared in FreeBSD 5.2 — yes, she's been here a minute, she's got seniority, she's the main character 👑

she is loosely based on the ubsa(4) driver by Alexander Kabaev <kan@FreeBSD.org>, with documentation from Wolfgang Grandeggar <wolfgang@cec.ch>. credit where credit is due, we love a documented origin story 🌸

⭐ AUTHORS ⭐

the umct driver was written by Scott Long <scottl@FreeBSD.org>. ty king, you ate and left zero crumbs 🔥💖

aaaand that's the whole page bestie!! 🎀 this lil manual page came from the Debian gang and it's dated April 26, 2017 — an absolute vintage, a classic, a real one ✨ now go plug in your RS-232 converter and go be great 💅🫶 no cap.

📦 where this page comes from