Skip to main content

IBM Systems  >   z Systems  >   z/VM  >  

Tim Greer's Home Page

Greetings. See my page introduction if you are interested. The prettiest pictures here are my favorite fractal creations. (The fractal animations are no longer available through this site.) Full mathematical details are available through the links below.

Here are some papers I have written.

I have degrees in three different subjects from three different schools. The most recent is an M.S. in Math from Georgia Tech. I don't get to use math in my work nearly as much as I'd like, so I look for applications in everyday life. Here are some examples.

  • Exploding satellites orbiting a black hole (No longer available)
  • Fiddle lessons (No longer available)
  • Throwing rocks off bridges
  • Psychological Experiment (No longer available)
  • How fast could I run a marathon?
  • How fast could you run a marathon? (No longer available)
  • Looking at the inside of the sun (No longer available)
  • How long do I have?
  • (With Ethan Greer) Smoke Alarm (Converts smoke alarm noise to a lower pitch audible to someone with high-frequency hearing loss.)

Several of my packages are in the VM Download Library :

  • CP1STLVL is a CP exit for second-level VM systems. It allows second-level users to invoke first-level commands without pausing the second-level system. It's handy in my software testing.
  • CPGRAB is a CP exit. I wrote it in order to grab, hold, and release certain CP locks.
  • SPITABCD is a test case generation tool, generating permutations of commands in a most-useful-first order. This package also includes a REXX program for raising polynomials to integer powers, which is useful for solving a "10 men each with 3 hats" combinatorics problem.
  • GETFILE is rather dated. It provided an FTP-like function.
  • OBFUSCAT is a tool to help you customize the way people surf into and through your VM-based web site.
  • CHUG is a tool we use in testing VM. Every night, CHUG generates hundreds of HTML files showing results of thousands of tests it controls.
  • SELFLGR allows you as a connected VM user to relocate yourself. The relocation function it applies to became available with z/VM 6.2.0. Most people will find it a novelty rather than actually useful. I created the tool to help with testing, but probably more because I kept being told that the thing it does couldn't be done.
  • RENSSI is a tool for renaming a member system of an SSI (Single System Image).
  • DR_DRCT is a pair of REXX EXECs addressing directory problems a VM System Administrator may encounter, plus other tools for working with VM directories.
  • D26C is a demonstration of invoking and receiving output from CP diagnose x'26C' from C. The diagnose has multiple subcodes relating to VSWITCHes, and so is primarily used by networking applications. D26C originated as a tool for testing the diagnose.

IBM folks may also access my Software Testing Symposium papers and tutorials on other topics on my internal page. But you can't link there unless you are inside the IBM firewall. Sorry.

If you haven't seen enough about fractals in the above links, take a look at St. Martins Press's book Fractal Horizons: The Future Use of Fractals (edited by Cliff Pickover), for which I wrote chapter 8. And after visiting all these other links, don't miss the riveting prose of my U. S. patents:

  • 5,574,798 Visual presentation system which determines length of time to present each slide or transparency
  • 5,642,430 Visual presentation system which determines length of time to present each slide or transparency
  • 5,973,665 Temporally invasive display guide
  • 5,987,466 Presenting web pages with discrete, browser-controlled complexity levels
  • 6,009,429 HTML guided web tour (To try this out, take one of the online tutorials on the CMS Pipelines page.)
  • 7,600,195 Selecting a menu option from a multiplicity of menu options which are automatically sequenced
  • 8,195,983 Method and system for evaluating software quality
  • 8,495,629 Virtual machine relocation system and associated methods
  • 9,183,122 Automated Program Testing to Facilitate Recreation of Test Failure

[Radioactive Self-Portrait] Around here, we like to do experimental nuclear physics...