.\"	$OpenBSD: zs.4,v 1.8 2015/11/23 10:37:20 mpi Exp $
.\"
.\" Copyright (c) 1998 The OpenBSD Project
.\" All rights reserved.
.\"
.\"
.Dd $Mdocdate: November 23 2015 $
.Dt ZS 4 macppc
.Os
.Sh NAME
.Nm zs ,
.Nm zstty
.Nd Zilog 8530 (ZSCC) serial communications driver
.Sh SYNOPSIS
.Cd "zs* at macobio?"
.Cd "zstty* at zs?"
.Sh DESCRIPTION
The
.Nm
is a Zilog 8530 serial interface chip used in
.Tn Sun
workstations and
.Tn Apple
Macintosh systems.
On most newer Macintosh systems, the first port
tty00
is connected to the internal modem.
The second port is either not connected, or may be connected to
an IRDA device (untested).
It is possible to replace the internal modem on some system with
a real serial port using third party hardware adapters.
.Pp
The
.Nm
driver supports all of the standard
.Xr tty 4
ioctl calls.
The status of the DTR, RTS, CTS, and DCD signals can be queried with
TIOCMGET command, but, due to limitations in the hardware,
only the DTR and RTS signals can be modified with TIOCMSET, TIOCMBIC,
and TIOCMBIS
.Xr ioctl 2
commands.
.Sh FILES
.Bl -tag -width Pa -compact
.It Pa /dev/tty00
.It Pa /dev/tty01
.It Pa /dev/cua00
.It Pa /dev/cua01
.El
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr intro 4 ,
.Xr tty 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Bx 4.4 .
Support for the TIOCM*
.Xr ioctl 2 Ns s
appeared in
.Ox 2.3 .
.Sh BUGS
The
.Nm
driver now supports cua minor devices, but with this known deficiency
in the simultaneous outgoing/incoming aspect of the driver:
The first outgoing connection succeeds, but second and subsequent
connections fail, apparently due to a getty hang.
The hung getty apparently prevents the cua device from being re-opened.