HP 98568A Installation Instruction page 472

HP 46081A Speaker Module
as three addressable devices. All other devices count as one addressable
device .
• The current requirements of all of your devices must not exceed 750
milliamps (rnA). To make sure you do not exceed this requirement, total
up the typical power required by each of your HP-HIL devices as given in
the following "Worksheet Entries" sections. If the total exceeds 750 rnA,
you must remove one or more devices.
10-30 Adding Miscellaneous Peripherals