The company that used to be Tymshare

Timeshared access to the 36-bit computers

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Tymshare was in the Top 10 for Silicon Valley Employers in 1982. Nathan Gregory is writing a book "Sharing the Computer", a more detailed history of Tymshare/Tymnet..
Tymcom-X history tidbit:

Tymshare's PDP-10s. It was a descendent of TOPS-10 but had many of the important features of TOPS-20 such as real paging and controllable/spawnable processes. TYMCOM-X, one of the best kept secrets in the PDP-10 folklore, was written by Bill Weiher, Vance Socci , Allen Ginzburg, Karen Kolling, Art Atkinson, Gary Morgenthaler, Todd Corenson and Murray Bowles. Some copies still run today. Most TYMNET development was done under TYMCOM-X and Tymshare sold a TYMCOM-X system to TRW to use in their credit reporting network, which was based on a purchased copy of TYMNET circa 1979.

[E-mail from Vance Socci 1994-05-20]

What follows is my personal history with the company.

Tymshare was purchased by McDonnell Douglas in 1984. The airplane company got rid of the Tymshare name, and renamed the Tymnet group to be McDonnell Douglas Network Systems Company. Tymshare's hardware people became McDonnell Douglas Field Service Company. The company also acquired Microdata (McDonnel Douglas Computer Systems Company) before deciding that diversifying into computers was a bad idea.

MDC sold the networking to British Telecom, who named it BT Tymnet for a while, then BTNA (BT North America). Then BT sold the networking group to MCI in return for forming a partnership of MCI + BT = Concert. BT was planning a merger with MCI when WorldCom made a better offer.

September 1998: merged company renamed to "MCI WorldCom".
June 2000: Company renamed to "WorldCom, Inc".
June 2002: The TYMNET X.25 Packet Network is scheduled to be shutdown.
Possible tie-in with the SC30M (36-bit computers) running Compuserve Classic.

Under Construction

Need to add more details here.

Up to the index for PDP-10 page.
Maintained by Joe Smith at