FLEX-ES Information

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zPDT Information

Reference Info
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zFrame Information
P/390 Information


FLEX-ES is the software from Fundemental Systems that provides full emulation of S/390 functions on an Intel architecture (IA32) based system. It is no longer available due to IBM restricions on the use of its' patents and refusal to license IBM software to run on FLEX-ES systems. There are many previously licensed FLEX-ES systems still running in support of commercial or production users. This page will have some information of largely historical interst and links to other sources for additional information. You should also refer to my Reference Page and the Links Page for more detailed information.
  • FLEX-ES refers to a collection of software; device drivers, deamons, scripts, utilities, application programs, and documentation that collectively allows an Intel Architecture based server to fully emulate a S/390 or zSeries system. It is available in several variations for different host software systems (UnixWare and Linux Versions are both available).
  • Although there are other S/390 emulators available today, FLEX-ES is unique in several respects:
    1. Fundemental Software licensed the right to implement S/390 features/functions from IBM. (Every copy of FLEX-ES sold paid a license fee to IBM.)
    2. FLEX-ES has been subjected to the same rigious testing for architectural complience as IBM hardware.
    3. FLEX-ES provides a very complete set of device support and/or emulation in addition to available high performance S/390 parallel and ESCON channels.
  • In the Cornerstone days I wrote a 19 page zFrame White Paper" about FLEX-ES and the zFrame product line that is a good readable overview with enough technical content to keep a technician happy.

Contact me via mike@hammocktree.us