---
name: "rc"
section: "4"
platform: "linux"
package: "freebsd-manpages"
version: "6.0-5"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/rc/4"
---

# rc(4)

RISCom/8 multiport card

## NAME

**rc** – RISCom/8 multiport card

## SYNOPSIS

**device** **isa** **device** **rc**

## DESCRIPTION

The RISCom/8 is an eight port ISA RS-232C communications multiplexer with a built in RISC processor. It uses a block of sixteen I/O ports in the range 0x200 to 0x3f0 selectable by on-board switches or jumpers. The block must be aligned on a sixteen port boundary. The jumper-selectable hardware interrupt level may be set to be detected during system initialization using settings found in the */boot/device.hints* file.

This driver is mostly based on the Cirrus Logic CL-CD180 driver.

## HARDWARE

The **rc** driver provides support for the SDL Communications RISCom/8 boards.

## DIAGNOSTICS

The following driver specific error messages may be reported:

- rc%d channel%d: interrupt-level buffer overflow

  An internal buffer overflow error has occurred on the listed channel. The **rc** driver will need to be reloaded to correct this.

- rc%d: Bad char chan %d

  The channel has obtained a bad set of characters.

- rc%d: Got extra chars chan %d

  The **rc** driver got more characters than expected on the channel shown.

- rc%d: data mismatch chan %d ptr %d (%d != %d)

  Data sent from channel *%d* to the rx buffer was different then expected.

- rc%d: channel %d command timeout, rc.c line: %d

  A command timeout has occurred on the channel, the *src/sys/dev/rc/rc.c* file can be consulted for more information.

## SEE ALSO

[tty(1)](/tty/1.md), [ttyname(3)](/ttyname/3.md), [sio(4)](/sio/4.md), [tty(4)](/tty/4.md), [device.hints(5)](/device.hints/5.md), [comcontrol(8)](/comcontrol/8.md), [getty(8)](/getty/8.md), [mutex(9)](/mutex/9.md), [splx(9)](/splx/9.md)

*http://www.sdlcomm.com*

## HISTORY

The **rc** driver first appeared in FreeBSD 2.0.5. This manual page first appeared in FreeBSD 5.3.

## AUTHORS

This manual page was written by Tom Rhodes ⟨trhodes@FreeBSD.org⟩.

## BUGS

The **rc** driver code still uses the [spl(9)](/spl/9.md) functions. These should be replaced by [mutex(9)](/mutex/9.md) functions.

The various **ttyld\_\***() functions should be documented.