The last Newton device released by Apple through their Newton Inc. subsidiary. The MessagePad 2100 shares the same specifications as its predecessor, the MessagePad 2000, with the exception of the amount of RAM. A MessagePad 2000 can been upgraded to the equivalent of a MessagePad 2100 by increasing the RAM from 5MB to 8MB.
Like its predecessor, the MessagePad 2000, the MessagePad 2100 was code named Q. It is commonly referred to as an MP2100.
Internet Archive: Press Release: Apple’s New MessagePad 2100