QMS 860, User Manual, Page: 56 / 398

additional information. See also QMS Crown Network Notes,
which came with your printer.
Simultaneous Interface Operation (SIO)
Simultaneous Interface Operation (SIO), a standard feature of
QMS Crown architecture, enables your QMS 860 Print System to
communicate simultaneously with hosts through the AppleTalk,
parallel, serial, and optional network interface (if installed) ports.
In other words, SIO allows you to have more than one host
communicating with the printer at one time. These ports are located
on the interface panel on the back of the printer and are labeled (fig.
3.1).
NOTE: The printer’s SCSI port, also located on the interface
panel, is used to connect up to seven optional hard disks
to the printer. It is covered by a metal bracket so it is not
confused with the serial port. This metal bracket needs to
be removed before installing a SCSI drive.
APPLETALK PARALLEL
OPTIONAL I/O
SCSI
SERIAL
Fig. 3.1 The QMS 860 Print System Interface Ports
Chapter 3
3 - 2 P r i n t e r - H o s t I n t e r f a c e