IBM 3274 51C Maintenance Information page 181

Ref
D
fJ
II
II
Ait IML
Address 8 4 2 1
0000
D
fJ
Description
On/Off switch:
m=
On;
l2J
=
Off.
On indicator: Indicates the 3274 is on.
IML (Initial Machine Load) pushbutton: Pressing
and holding causes a basic test to run. When the
pushbutton is released, 1M L tests start. At com-
pletion, the machine is loaded.
Alt IML Address switch:
• 1: Holding, while pressing the IML pushbutton,
bypasses the tests and loads the machine
directly. Use only after normal IML fails.
• 2: Holding, while pressing the IML pushbutton,
invokes adapter and wrap tests.
Figure D-l. 3274 Operator Panel - Model 51C with Digital Data
Service (DDS) Adapter or Models 51C/52C with X.21
with/without Encrypt/Decrypt Feature
Model51C
Only
Ref
fJ
Description
8 4 2 1 indicators: These light while the 1M L push-
button is held. During IML, they follow the test
sequence. At completion, they all go out. During
operation, they indicate operational status.
Encrypt/Decrypt Battery - Allows the master key
to be maintained in the 3274 when power is off.
Encrypt/Decrypt Key Switch - Allows a new master
key to be entered when in the horizontal position.
Appendix D. Operator and Control Panels D-3