Interface; Feature Connector - IBM RT Series Hardware Reference Manual

Interface
Feature Connector
The following is a description of the Enhanced Graphics Adapter
feature connector. Note that signals coming from the Enhanced
Graphics Adapter are labeled "inputs" and the signals coming to
the Enhanced Graphics Adapter through the feature connector
are labeled "outputs".
Signal Description
J2 This pin is connected to auxiliary jack 2 on the rear
panel of the adapter.
R'OUT Secondary red output
ATRS/L Attribute shift load. This signal controls the
serialization of the video information. The shift
register parallel loads at the dot clock leading edge
when this signal is low.
G OUT Primary green output
R' Secondary red input
R Primary red input
FC1
This signal is input from bit 1 (Feature Control Bit
1) of the Feature Control Register.
FCO This signal is input from bit 0 (Feature Control Bit
0) of the Feature control Register.
FEAT 0 This signal is output to bit 5 (Feature Code 0) of
Input Status Register O.
B' /V Secondary blue input/Monochrome video
VIN Vertical retrace input
76 IBM Enhanced Graphics Adapter