Control Data Corporation 6000 Series Reference Manual page 16

Control Signals
Communication signals between the 6675 Data Set Controller and the computer or
between the 6675 Data Set Controller and the data set are listed in Tables 3-2 and
3-3 (Figure 2-2). Understanding the function of these signals clarifies the purpose
of certain function or status codes. Communication signals are not transferred over
data lines.
DSC CONTROL PANEL
MULTIPLEXER CONTROL PANEL
Figure 3-1. 6675 Control Panel
Rev. A 3-3