Primary/Alternate Address Jumper - IBM RT PC Options Installation

Primary /Alternate Address Jumper
6-24 Options Installation
The position of jumper module J3 sets the adapter I/O address as
Primary (the default setting) or Alternate. Jumper J3 also sets the
DMA level at 5 for Primary and 6 for Alternate. To change J3, do the
following:
1. Carefully insert a small, flat-bladed screwdriver under the J3
jumper module, alternately lifting the ends to extract the module
evenly.
Warning: Do not bend the pins!
2. Turn the module 180º and reinstall.