Setting or changing the mode of an I/O card

How to set or change the mode of an I/O card

The 2748 and 2778 I/O cards support two modes: compression and enhanced. The rear of the I/O card is marked with a C, indicating compression mode, and an E, indicating enhanced mode. Three pins on the rear of the I/O card determine the mode of the card, depending on which of the pins have a jumper placed on them.

The jumper may be moved at any time, but changes only take effect during a system IPL. Refer to the illustration below while changing the mode jumper.

Figure 1. Changing the mode jumper

Power off the system, ensuring that no jobs are currently processing (see Powering on and powering off).
Choose from the following options:
- To set the mode of the card to compressed (C), place the jumper on the top and middle pins.
- To set the mode of the card to enhanced (E), place the jumper on the middle and bottom pins.
Select the IPL type and mode. See IPL type, mode, and speed options for details.
Power on the system.

For information on disk compression, see the "Choose compression type" information in the Backup and Recovery Link to PDF book.