Apple Color OneScanner 600/27 - Manual (Page 15)

To connect the scanner directly to the Macintosh
To connect the scanner directly to your Macintosh computer, you need a SCSI
system cable.
To connect the scanner at the end of a SCSI chain
If you already have an external SCSI device (such as a SCSI hard disk drive)
attached to your Macintosh computer, Apple recommends that you connect
the scanner at the end of the SCSI chain.
To make this connection, you need a SCSI peripheral cable.
To use a different arrangement (configuration)
For information about connecting the scanner in the middle of a SCSI chain,
see Appendix C, “Assembling a SCSI Chain.”
SCSI peripheral cable
SCSI system cable (one end
is smaller than the other)
7 Setting Up the Scanner