IBM 3270 Manual page 161

6-8
3. Insert the system diskette (see Figure 6-3) and, holding the Alt IML
Address switch in position 1, press and release the IM L pushbutton;
then release the Alt IM L Address switch. Within 1 minute, the 8 4 2 1
indicator code will be flashing 0011.
4. Insert the load diskette. Do not press the /ML pushbutton. Within 1
minute, the indicator code will change to a 1000 and remain this way for
approximately 15 minutes. Then the indicator code wil I change to a
solid 1111, indicating backup load diskette generation is successfully
completed. If errors occur during this 15-minute period, a flashing 8 4 2 1
indicator code will appear. Figures 6-5 and 6-6 may help you locate the
cause.
The newly created backup load diskette may now be used as well as the
existing customized load diskette.
Be sure the 3274 is attached to the appropriate cpmmunication facility.
The backup load diskette may now be used to initiate an IML of the 3274
Control Unit. During IM L, errors may occur because of improper backup
diskette creation. The 8 4 2 1 indicator codes caused by these errors are
shown in Figure 6-7.
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