EO Personal Communicator

The EO is an early commercial tablet computer that was created by Eo, Inc. (later acquired by AT&T Corporation), and released in April 1993. Eo (Latin for "I go") was the hardware spin-out of GO. Officially named the AT&T EO Personal Communicator, it was similar to a large personal digital assistant with wireless communications, and competed against the Apple Newton. The unit was produced in conjunction with David Kelley Design, frog design, and the Matsushita, Olivetti and Marubeni corporations.
Among the EO customers AT&T claimed were: New York Stock Exchange, Andersen Consulting, Lawrence Livermore Laboratories, FD Titus & Sons and Woolworths.
Eo, Inc., 52 percent owned by AT&T, shut down operations on July 29, 1994, after failing to meet its revenue targets and to secure the funding to continue. It was reported that 10,000 of the computers had been sold.
In 2012, PC Magazine called the AT&T EO 440, "the first true phablet".
Product specifics.
Two models, the Communicator 440 and 880, were produced and measured about the size of a small clipboard. Both were powered by the AT&T Hobbit chip, created by AT&T specifically for running code from the C programming language. They had a host of I/O ports – modem, parallel, serial, VGA out and SCSI. The devices came with a wireless cellular network modem, a built-in microphone with speaker, and a free subscription to AT&T EasyLink Mail for both fax and e-mail messages.
Perhaps the most interesting part was the operating system, PenPoint OS, created by GO Corporation. Widely praised for its simplicity and ease of use, the OS never gained widespread use. Equally compelling was the tightly integrated applications suite, Perspective, licensed to EO by Pensoft.