Apple Macintosh 6500 - Manual (Page 57)

Connecting external SCSI devices, such as a scanner or external hard disk
Your computer has a port for connecting devices that use the Small Computer
System Interface (SCSI, pronounced “skuh-zee”). SCSI devices commonly
used with the Macintosh include hard disk drives, CD-ROM drives, scanners,
tape or cartridge backup drives, and some printers. The SCSI port permits
high-speed communication between the computer and the device. The SCSI
icon appears underneath the port on the computer’s back panel.
You can connect several SCSI devices to the SCSI port by linking them to
create a chain of devices. The first device in the chain plugs into the SCSI
port; the second device plugs into the first device, and so on. You can attach
up to six external SCSI devices to the SCSI port (or up to five if you have an
additional SCSI drive installed in your computer). Each SCSI device
connected to this chain must have its own unique ID number (no two devices
can use the same ID number). If your computer came with a CD-ROM drive
installed, this drive is also part of the SCSI chain and uses SCSI ID number 3.
The computer itself (the main logic board inside it) uses SCSI ID number 7.
IMPORTANT The material that follows—“Before You Connect a Device” and
“Connecting a SCSI Device”—contains general instructions for attaching
SCSI devices to your computer. Make sure you also follow the specific
instructions that came with the SCSI device you are connecting to your
Macintosh.
SCSI port
SCSI icon
57 Expanding Your Computer and Using Its Special Features