How Much Power Can a PCMCIA Card Draw

One of the Newton 2.x OS Q&As
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This document was exported on 7/23/97.

How Much Power Can a PCMCIA Card Draw (3/31/95)

Q: How much power can I draw through the PCMCIA slot?

A: The current rating depends on which Newton you are using and the type of batteries in use. Alkaline batteries provide less current than NiCad due to higher internal resistance. There is also a 'semi' artifical limit in the ROM. Currently any card who's CIS indicates more than 200 mA current draw will be rejected by the CardHandler. Other than that, here's the run down by hardware:

    Apple MessagePad 100:      50 mA
    Apple MessagePad 110:    ~160 mA
    Apple MessagePad 120:    ~300 mA
    Apple MessagePad 130:    ~300 mA (with backlight off)
    Apple MessagePad 130:    (with backlight on, the maximum has not been characterized)