ucom(4)

ucom4

Usb tty support

Usage

ucom* at moscom? # MosChip Semiconductor MCS7703 ucom* at uark? # Arkmicro Technologies ucom* at ubsa? # Belkin ucom* at uchcom? # WinChipHead CH9102/343/341/340 ucom* at ucycom? # Cypress ucom* at uftdi? # FTDI ucom* at uipaq? # iPAQ ucom* at ukspan? # Keyspan ucom* at umcs? # MosChip Semiconductor multiport ucom* at umct? # MCT ucom* at umodem? # Standardized umodem ucom* at umsm? # Qualcomm MSM ucom* at uplcom? # Prolific PL-2303 ucom* at uscom? # simple USB serial adapters ucom* at uslcom? # Silicon Laboratories CP2101/CP2102 ucom* at uslhcom? # Silicon Laboratories CP2110 ucom* at uticom? # Texas Instruments TUSB3410 ucom* at uvisor? # Handspring Visor ucom* at uvscom? # SUNTAC Slipper U VS-10U ucom* at uxrcom? # Exar XR21V1410

Overview

The ucom driver attaches to USB modems, serial ports, and other devices that need to look like a tty. The ucom driver behaves like a tty(4): this means that normal programs such as cu(1) or pppd(8) can be used to access the device.

The portno locator can be used to decide which port to use for devices that have multiple external ports.

Files

/dev/ttyU?

tty devices

/dev/cuaU?

call out devices (see tty(4))

Releases

54 releases since OpenBSD 2.8; the text changed 21 times.

  1. 2.8
  2. 2.9
  3. 3.0–3.1
  4. 3.2
  5. 3.3
  6. 3.4
  7. 3.5–3.6
  8. 3.7
  9. 3.8
  10. 3.9
  11. 4.0
  12. 4.1
  13. 4.2
  14. 4.3
  15. 4.4–4.6
  16. 4.7–5.6
  17. 5.7
  18. 5.8
  19. 5.9–6.4
  20. 6.5
  21. 6.6–7.5
  22. 7.6–8.0

History

The ucom driver appeared in NetBSD 1.5. OpenBSD support was added in OpenBSD 2.7.

From man 8.0-current-20261101 in OpenBSD 8.0-current (2026-11-01). Parsed by carta from the page's mdoc source.