---
name: "boca"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/boca"
---

# boca(4)

multiplexing serial communications interface

## NAME

**boca** – multiplexing serial communications interface

## SYNOPSIS

For 4-port BB1004 boards and 8-port BB1008 boards:

**boca0 at isa? port 0x100 irq 5** **com\* at boca?**

For 16-port BB2016 boards:

**boca0 at isa? port 0x100 irq 5** **boca1 at isa? port 0x140 irq 5** **com\* at boca?**

(The BB2016 is functionally equivalent to two BB1008 boards, and is configured as such.)

## DESCRIPTION

The **boca** driver provides support for BOCA Research BB1004, BB1008, and BB2016 boards that multiplex together up to four, eight, or sixteen EIA RS-232C (CCITT V.28) communications interfaces.

Each **boca** device is the master device for up to eight **com** devices. The kernel configuration specifies these **com** devices as slave devices of the **boca** device, as shown in SYNOPSIS. The slave ID given for each **com** device determines which bit in the interrupt multiplexing register is tested to find interrupts for that device. The **port** specification for the **boca** device is used to compute the base addresses for the **com** subdevices and the port for the interrupt multiplexing register.

## FILES

- */dev/tty??*

  ## SEE ALSO

[com(4)](/com/4.md), [intro(4)](/intro/4.md), [isa(4)](/isa/4.md)

## HISTORY

The **boca** driver was written by Charles Hannum, based on the **ast** driver and source code from David Muir Sharnoff. David wishes to acknowledge the assistance of Jason Venner in determining how to use the BOCA boards.