Expansion Unit - IBM Personal Computer XT Manual To Operations

Expansion Unit
The expansion unit comes with a fixed disk drive.
When you install the expansion unit, you have to
remove the fixed disk drive and fixed disk adapter from
the system unit and install them in the expansion unit.
The fixed disk adapter then controls both fixed disk
drives. You also have to install an extender card in the
system unit. The extender card goes in the slot
previously occupied by the fixed disk adapter. A cable
connected to the extender card and to the receiver card
in the expansion unit completes the electrical
connection between the system unit and expansion unit.
The expansion unit has six expansion slots where
additional options may be installed.
The expansion unit has only one control-the Power
switch. When switching power on to the IBM Personal
Computer XT, remember to switch on the expansion
unit before the system unit. If this is not done, an error
message will appear on the screen. To recover from
this condition, you have to switch power off on all
devices, then switch it back on, with the expansion unit
being switched on first.
Expansion Unit 3-17