ZS(4)                OpenBSD Programmer's Manual (SPARC64)               ZS(4)

NAME
     zs - Zilog 8530 (ZSCC) serial communications driver

SYNOPSIS
     zs* at sbus? slot ? offset ?
     zstty* at zs? channel ?

DESCRIPTION
     The zs is a Zilog 8530 serial interface chip used in SBus-based ULTRA-
     sparc Sun workstations.  The Zilog 8530 provides two input/output chan-
     nels per instance.  Most Sun workstations include two of these inter-
     faces.  One of the interfaces is usually hardwired for use by the key-
     board and mouse attached to the workstation console.  The remaining addi-
     tional zs interfaces provide RS-423 and RS-232 serial ports for general
     purpose use.

     The zs driver supports all of the standard tty(4) ioctl calls.  The sta-
     tus 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 ioctl(2)
     commands.

BUGS
     The zs driver now supports cua minor devices, but with this known defi-
     ciency 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.

SEE ALSO
     ioctl(2), kbd(4), ms(4), tty(4)

HISTORY
     The zs driver first appeared in 4.4BSD. Support for the TIOCM* ioctl(2)s
     appeared in OpenBSD 2.3.

OpenBSD 3.0                      March 4, 1998                               1
