IBM 7013 J Series, Operator'S Manual

Page: 38 / 297

2-6
Operator Guide
Setting the Key Mode Switch
The key mode switch has three positions:
Normal Position
Secure Position
Service Position
The switch is used to establish the initial program load (IPL) path. The IPL loads the system
programs, checks the system hardware and prepares the system for user operation.
Before starting the system unit for normal day-to-day-operation, set the key mode switch to
the normal position. This permits the operating system to load after the power-on-self-tests
(POST’s) are completed.
Note: It is possible to set the Electronic Mode Switch (E-Key) through SystemGuard
firmware from the local or remote SystemGuard BUMP console. In Normal mode an
electronic key may be used to set Normal, Secure and Service modes. For remote
maintenance, see “Electronic Mode Switch” page 2-8. In Secure and Service
modes, the physical key setting prevails.
Operator Panel with Key Mode Switch in Normal Position
Key Mode Switch
The following table summarizes the possible operations for each key mode switch position:
Operation Key Mode Switch Position
Normal Secure Service
Reset Enabled Disabled Enabled
BUMP Console Active Enabled Enabled Enabled
BUMP Console Debug/
Dump Disabled Disabled Enabled
Normal IPL Enabled Disabled Disabled
Service IPL Disabled Disabled Enabled
Note: In this information, the name SystemGuard BUMP Console refers to the Local
Console connected to the S1 port on the system interface board.