Sun Microsystems Sun Workstation 100U System Manager's Manual page 29

Sun 100/150 Installation Manual Unpacking and Setting up the 150U
NOTE
that older workstations (shipped prior to the 1.0 Release) have serial port A configured
as a DCE (Data Communications Equipment) and serial port B configured as a DTE. In addi-
tion, only serial port A on the older workstations has full modem control. This means that
external cables built for the Sun-lor Sun-I.5 CPU may have to be modified to work correctly
with the Sun-2 CPU, or a null modem cable (such as that supplied by Sun) may be required.
See the A,ynchronou, Serial Port, section
or
the Hardware Oonfiguration a.nd Ezpa.n,;on chapter
for wiring specifications.
The serial ports on the Sun Workstation were designed primarily for connecting output peri-
pherals, such as printers and plotters, and can drive these output lines at speeds up to 19.2
Kbaud. Both ports provide the CTS, RTS, DTR, DSR, and DCD control lines required by
some devices (such as modems) in addition to the transmit and receive lines; the ports generate
DTR and RTS, and pay attention to DSR, CTS, and DCD. Both ports are also wired as DTE
(Data Terminal direct connection of modems. Computers and other DTE devices can be con-
nected using the null modem cable supplied by Sun. See the A'1JRchronou, Ser'a.l Port, section
of the Hardware Configuration and Ezpan,ion chapter for wiring specifications.
Revision H of 12 March 1984
2-7